Commit 558a9165e0 taught _bt_delitems_delete() to produce its own XID
horizon on the primary. Standbys no longer needed to generate their own
latestRemovedXid, since they could just use the explicitly logged value
from the primary instead. The deleted offset numbers array from the
xl_btree_delete WAL record was no longer used by the REDO routine for
anything other than deleting the items.
This enables a minor optimization: We now treat the array as buffer
state, not generic WAL data, following _bt_delitems_vacuum()'s example.
This should be a minor win, since it allows us to avoid including the
deleted items array in cases where XLogInsert() stores the whole buffer
anyway. The primary goal here is to make the code more maintainable,
though. Removing inessential differences between the two functions
highlights the fundamental differences that remain.
Also change xl_btree_delete to use uint32 for the size of the array of
item offsets being deleted. This brings xl_btree_delete closer to
xl_btree_vacuum. Furthermore, it seems like a good idea to use an
explicit-width integer type (the field was previously an "int").
Bump XLOG_PAGE_MAGIC because xl_btree_delete changed.
Discussion: https://postgr.es/m/CAH2-Wzkz4TjmezzfAbaV1zYrh=fr0bCpzuJTvBe5iUQ3aUPsCQ@mail.gmail.com
Adjust a comment that describes how alignment of the new left page high
key works in btree_xlog_split(), the nbtree page split REDO routine.
The wording used before commit 2c03216d83 is much clearer, so go back
to that.
When row triggers exist in partitioned partitions that are not either
part of FKs or deferred unique constraints, they are not correctly
cloned to their partitions. That's because they are marked "internal",
and those are purposefully skipped when doing the clone triggers dance.
Fix by relaxing the condition on which internal triggers are skipped.
Amit Langote initially diagnosed the problem and proposed a fix, but I
used a different approach.
Reported-by: Petr Fedorov
Discussion: https://postgr.es/m/6b3f0646-ba8c-b3a9-c62d-1c6651a1920f@phystech.edu
On further reflection about commit 4d02eb017, it occurs to me that
expandRTE() had better agree with what addRangeTableEntryForFunction()
is doing. So teach that about functions possibly having typmods, too.
One code path in addRangeTableEntryForFunction() neglected to assign
a collation to the tupdesc entry it constructs (which is a bit odd
considering the other path did do so). This didn't matter before commit
5815696bc, because nothing would look at the type data in this tupdesc;
but now it does.
While at it, make sure we assign the correct typmod as well. Most
function expressions don't have a determinate typmod, but some do.
Per buildfarm, which showed failures in non-C collations, a case
I'd not thought to test for this patch :-(
When I added the ParseNamespaceItem data structure (in commit 5ebaaa494),
it wasn't very tightly integrated into the parser's APIs. In the wake of
adding p_rtindex to that struct (commit b541e9acc), there is a good reason
to make more use of it: by passing around ParseNamespaceItem pointers
instead of bare RTE pointers, we can get rid of various messy methods for
passing back or deducing the rangetable index of an RTE during parsing.
Hence, refactor the addRangeTableEntryXXX functions to build and return
a ParseNamespaceItem struct, not just the RTE proper; and replace
addRTEtoQuery with addNSItemToQuery, which is passed a ParseNamespaceItem
rather than building one internally.
Also, add per-column data (a ParseNamespaceColumn array) to each
ParseNamespaceItem. These arrays are built during addRangeTableEntryXXX,
where we have column type data at hand so that it's nearly free to fill
the data structure. Later, when we need to build Vars referencing RTEs,
we can use the ParseNamespaceColumn info to avoid the rather expensive
operations done in get_rte_attribute_type() or expandRTE().
get_rte_attribute_type() is indeed dead code now, so I've removed it.
This makes for a useful improvement in parse analysis speed, around 20%
in one moderately-complex test query.
The ParseNamespaceColumn structs also include Var identity information
(varno/varattno). That info isn't actually being used in this patch,
except that p_varno == 0 is a handy test for a dropped column.
A follow-on patch will make more use of it.
Discussion: https://postgr.es/m/2461.1577764221@sss.pgh.pa.us
Currently while decoding changes, if the number of changes exceeds a
certain threshold, we spill those to disk. And this happens for each
(sub)transaction. Now, while reading all these files, we don't close them
until we read all the files. While reading these files, if the number of
such files exceeds the maximum number of file descriptors, the operation
errors out.
Use PathNameOpenFile interface to open these files as that internally has
the mechanism to release kernel FDs as needed to get us under the
max_safe_fds limit.
Reported-by: Amit Khandekar
Author: Amit Khandekar
Reviewed-by: Amit Kapila
Backpatch-through: 9.4
Discussion: https://postgr.es/m/CAJ3gD9c-sECEn79zXw4yBnBdOttacoE-6gAyP0oy60nfs_sabQ@mail.gmail.com
_bt_delitems_vacuum() comments claimed that it isn't worth another scan
of the page to avoid falsely unsetting the BTP_HAS_GARBAGE page flag
hint (this happens to be the same wording that was removed from
_bt_delitems_delete() by my recent commit fe97c61c). The comments made
little sense, though. The issue can't have much to do with performing a
second scan of the target leaf page, since an LP_DEAD test could easily
be performed in the first scan of the page anyway (the scan that takes
place in btvacuumpage() caller).
Revise the explanation. It makes much more sense to frame this as an
issue about recovery conflicts. _bt_delitems_vacuum() cannot easily
generate an XID cutoff in the same way that _bt_delitems_delete() is
designed to.
Falsely unsetting the page flag is not ideal, and is likely to happen
more often than was supposed by the original comments. Explain why it
usually isn't a problem in practice. There may be an argument for
_bt_delitems_vacuum() not clearing the BTP_HAS_GARBAGE bit, removing the
question of it being falsely unset by VACUUM (there may even be an
argument for not using a page level hint at all). This can be revisited
later.
Commit fe97c61c updated LP_DEAD item deletion comments, but missed a
minor discrepancy on the REDO side. Fix it now.
In passing, don't talk about the btree_xlog_vacuum() behavior within
btree_xlog_delete(). The reliance on XLOG_HEAP2_CLEANUP_INFO records
for recovery conflicts is already discussed within btvacuumpage() and
mentioned again in passing above btree_xlog_vacuum(), which seems
sufficient.
Use __builtin_clz() where available. Where it isn't, we can still win
a little by using the pg_leftmost_one_pos[] lookup table instead of
having a private table.
Also drop the initial right shift by ALLOC_MINBITS in favor of
subtracting ALLOC_MINBITS from the leftmost-one-pos result. This
is a win because the compiler can fold that adjustment into other
constants it'd have to add anyway, making the shift-removal free.
Also, we can explain this coding as an unrolled form of
pg_leftmost_one_pos32(), even though that's a bit ahistorical
since it long predates pg_bitutils.h.
John Naylor, with some cosmetic adjustments by me
Discussion: https://postgr.es/m/CACPNZCuNUGMxjK7WTn_=WZnRbfASDdBxmjsVf2+m9MdmeNw_sg@mail.gmail.com
This operation was possible for the owner of the schema or a superuser.
Down to 9.4, doing this operation would cause inconsistencies in a
session whose temporary schema was dropped, particularly if trying to
create new temporary objects after the drop. A more annoying
consequence is a crash of autovacuum on an assertion failure when
logging information about an orphaned temp table dropped. Note that
because of 246a6c8 (present in v11~), which has made the removal of
orphaned temporary tables more aggressive, the failure could be
triggered more easily, but it is possible to reproduce down to 9.4.
Reported-by: Mahendra Singh, Prabhat Sahu
Author: Michael Paquier
Reviewed-by: Kyotaro Horiguchi, Mahendra Singh
Discussion: https://postgr.es/m/CAKYtNAr9Zq=1-ww4etHo-VCC-k120YxZy5OS01VkaLPaDbv2tg@mail.gmail.com
Backpatch-through: 9.4
This follows multiple complains from Peter Geoghegan, Andres Freund and
Alvaro Herrera that this issue ought to be dug more before actually
happening, if it happens.
Discussion: https://postgr.es/m/20191226144606.GA5659@alvherre.pgsql
Instead of passing around a pointer to the RangeTblEntry that
provides the desired column, pass a pointer to the associated
ParseNamespaceItem. The RTE is trivially reachable from the nsitem,
and having the ParseNamespaceItem allows access to additional
information. As proof of concept for that, add the rangetable index
to ParseNamespaceItem, and use that to get rid of RTERangeTablePosn
searches.
(I have in mind to teach the parser to generate some different
representation for Vars that are nullable by outer joins, and
keeping the necessary information in ParseNamespaceItems seems
like a reasonable approach to that. But whether that ever
happens or not, this seems like good cleanup.)
Also refactor the code around scanRTEForColumn so that the
"fuzzy match" stuff does not leak out of parse_relation.c.
Discussion: https://postgr.es/m/26144.1576858373@sss.pgh.pa.us
The part in charge of doing the vacuum on all the indexes of a relation
was duplicated, with the same handling for progress reporting done.
While on it, update the progress reporting for heap vacuuming in the
subroutine doing the actual work, keeping the status update local. This
way, any future caller of lazy_vacuum_heap() does not have to worry
about doing any progress reporting update.
Author: Justin Pryzby, Michael Paquier
Discussion: https://postgr.es/m/20191120210600.GC30362@telsasoft.com
In the wake of commit 5b9312378, there's no particular reason
for this restriction (previously, it was problematic because of
the implied rowtype reference). A simple constraint on a whole-row
Var probably isn't that useful, but conceivably somebody would want
to pass one to a function that extracts a partitioning key. Besides
which, we're expending much more code to enforce the restriction than
we save by having it, since the latter quantity is now zero.
So drop the restriction.
Amit Langote
Discussion: https://postgr.es/m/CA+HiwqFUzjfj9HEsJtYWcr1SgQ_=iCAvQ=O2Sx6aQxoDu4OiHw@mail.gmail.com
Formerly the rd_partkey and rd_partdesc data structures were always
populated immediately when a relcache entry was built or rebuilt.
This patch changes things so that they are populated only when they
are first requested. (Hence, callers *must* now always use
RelationGetPartitionKey or RelationGetPartitionDesc; just fetching
the pointer directly is no longer acceptable.)
This seems to have some performance benefits, but the main reason to do
it is that it eliminates a recursive-reload failure that occurs if the
partkey or partdesc expressions contain any references to the relation's
rowtype (as discovered by Amit Langote). In retrospect, since loading
these data structures might result in execution of nearly-arbitrary code
via eval_const_expressions, it was a dumb idea to require that to happen
during relcache entry rebuild.
Also, fix things so that old copies of a relcache partition descriptor
will be dropped when the cache entry's refcount goes to zero. In the
previous coding it was possible for such copies to survive for the
lifetime of the session, as I'd complained of in a previous discussion.
(This management technique still isn't perfect, but it's better than
before.) Improve the commentary explaining how that works and why
it's safe to hand out direct pointers to these relcache substructures.
In passing, improve RelationBuildPartitionDesc by using the same
memory-context-parent-swap approach used by RelationBuildPartitionKey,
thereby making it less dependent on strong assumptions about what
partition_bounds_copy does. Avoid doing get_rel_relkind in the
critical section, too.
Patch by Amit Langote and Tom Lane; Robert Haas deserves some credit
for prior work in the area, too. Although this is a pre-existing
problem, no back-patch: the patch seems too invasive to be safe to
back-patch, and the bug it fixes is a corner case that seems
relatively unlikely to cause problems in the field.
Discussion: https://postgr.es/m/CA+HiwqFUzjfj9HEsJtYWcr1SgQ_=iCAvQ=O2Sx6aQxoDu4OiHw@mail.gmail.com
Discussion: https://postgr.es/m/CA+TgmoY3bRmGB6-DUnoVy5fJoreiBJ43rwMrQRCdPXuKt4Ykaw@mail.gmail.com
The following renaming is done so as source files related to index
access methods are more consistent with table access methods (the
original names used for index AMs ware too generic, and could be
confused as including features related to table AMs):
- amapi.h -> indexam.h.
- amapi.c -> indexamapi.c. Here we have an equivalent with
backend/access/table/tableamapi.c.
- amvalidate.c -> indexamvalidate.c.
- amvalidate.h -> indexamvalidate.h.
- genam.c -> indexgenam.c.
- genam.h -> indexgenam.h.
This has been discussed during the development of v12 when table AM was
worked on, but the renaming never happened.
Author: Michael Paquier
Reviewed-by: Fabien Coelho, Julien Rouhaud
Discussion: https://postgr.es/m/20191223053434.GF34339@paquier.xyz
Using \ is unnecessary and ugly, so remove that. While at it, stitch
the literals back into a single line: we've long discouraged splitting
error message literals even when they go past the 80 chars line limit,
to improve greppability.
Leave contrib/tablefunc alone.
Discussion: https://postgr.es/m/20191223195156.GA12271@alvherre.pgsql
Our algorithm for choosing batch numbers turned out not to work
effectively for multi-billion key inner relations. We would use
more hash bits than we have, and effectively concentrate all tuples
into a smaller number of batches than we intended. While ideally
we should switch to wider hashes, for now, change the algorithm to
one that effectively gives up bits from the bucket number when we
don't have enough bits. That means we'll finish up with longer
bucket chains than would be ideal, but that's better than having
batches that don't fit in work_mem and can't be divided.
Batch-patch to all supported releases.
Author: Thomas Munro
Reviewed-by: Tom Lane, thanks also to Tomas Vondra, Alvaro Herrera, Andres Freund for testing and discussion
Reported-by: James Coleman
Discussion: https://postgr.es/m/16104-dc11ed911f1ab9df%40postgresql.org
This wasn't checked originally, but it should have been, because
in general pseudo-types can't be stored to and retrieved from disk.
Notably, partition bound values of type "record" would not be
interpretable by another session.
In v12 and HEAD, add another flag to CheckAttributeType's repertoire
so that it can produce a specific error message for this case. That's
infeasible in older branches without an ABI break, so fall back to
a slightly-less-nicely-worded error message in v10 and v11.
Problem noted by Amit Langote, though this patch is not his initial
solution. Back-patch to v10 where partitioning was introduced.
Discussion: https://postgr.es/m/CA+HiwqFUzjfj9HEsJtYWcr1SgQ_=iCAvQ=O2Sx6aQxoDu4OiHw@mail.gmail.com
We probably should have thought of this case when ranges were added,
but we didn't. (It's not the fault of commit eb51af71f, because
ranges didn't exist then.)
It's an old bug, so back-patch to all supported branches.
Discussion: https://postgr.es/m/7782.1577051475@sss.pgh.pa.us
Comments about the consequences of clearing the BTP_HAS_GARBAGE page
flag bit that apply only to VACUUM were added to code that deals with
opportunistic deletion of LP_DEAD items by commit a760893d. The same
comment block was added to both _bt_delitems_vacuum() and
_bt_delitems_delete(). Correct _bt_delitems_delete()'s copy of the
comment block.
_bt_delitems_delete() reliably deletes items that were found by caller
to have their LP_DEAD bit set. There is no question about whether or
not unsetting the BTP_HAS_GARBAGE bit can miss some LP_DEAD items that
were set recently.
Also tweak a related section of the nbtree README.
A new function EmitProcSignalBarrier() can be used to emit a global
barrier which all backends that participate in the ProcSignal
mechanism must absorb, and a new function WaitForProcSignalBarrier()
can be used to wait until all relevant backends have in fact
absorbed the barrier.
This can be used to coordinate global state changes, such as turning
checksums on while the system is running.
There's no real client of this mechanism yet, although two are
proposed, but an enum has to have at least one element, so this
includes a placeholder type (PROCSIGNAL_BARRIER_PLACEHOLDER) which
should be replaced by the first real client of this mechanism to
get committed.
Andres Freund and Robert Haas, reviewed by Daniel Gustafsson and,
in earlier versions, by Magnus Hagander.
Discussion: http://postgr.es/m/CA+TgmoZwDk=BguVDVa+qdA6SBKef=PKbaKDQALTC_9qoz1mJqg@mail.gmail.com
The REDO routine for nbtree's xl_btree_vacuum record type hasn't
performed a "pin scan" since commit 3e4b7d87 went in, so clearly there
isn't any point in VACUUM WAL-logging information that won't actually be
used. Finish off the work of commit 3e4b7d87 (and the closely related
preceding commit 687f2cd7) by removing the code that generates this
unused information. Also remove the REDO routine code disabled by
commit 3e4b7d87.
Replace the unneeded lastBlockVacuumed field in xl_btree_vacuum with a
new "ndeleted" field. The new field isn't actually needed right now,
since we could continue to infer the array length from the overall
record length. However, an upcoming patch to add deduplication to
nbtree needs to add an "items updated" field to xl_btree_vacuum, so we
might as well start being explicit about the number of items now.
(Besides, it doesn't seem like a good idea to leave the xl_btree_vacuum
struct without any fields; the C standard says that that's undefined.)
nbtree VACUUM no longer forces writing a WAL record for the last block
in the index. Writing out a WAL record with no items for the final
block was supposed to force processing of a lastBlockVacuumed field by a
pin scan.
Bump XLOG_PAGE_MAGIC because xl_btree_vacuum changed.
Discussion: https://postgr.es/m/CAH2-WzmY_mT7UnTzFB5LBQDBkKpdV5UxP3B5bLb7uP%3D%3D6UQJRQ%40mail.gmail.com
The previous coding imagined that it could call before_shmem_exit()
when a non-exclusive backup began and then remove the previously-added
handler by calling cancel_before_shmem_exit() when that backup
ended. However, this only works provided that nothing else in the
system has registered a before_shmem_exit() hook in the interim,
because cancel_before_shmem_exit() is documented to remove a callback
only if it is the latest callback registered. It also only works
if nothing can ERROR out between the time that sessionBackupState
is reset and the time that cancel_before_shmem_exit(), which doesn't
seem to be strictly true.
To fix, leave the handler installed for the lifetime of the session,
arrange to install it just once, and teach it to quietly do nothing if
there isn't a non-exclusive backup in process.
This is a bug, but for now I'm not going to back-patch, because the
consequences are minor. It's possible to cause a spurious warning
to be generated, but that doesn't really matter. It's also possible
to trigger an assertion failure, but production builds shouldn't
have assertions enabled.
Patch by me, reviewed by Kyotaro Horiguchi, Michael Paquier (who
preferred a different approach, but got outvoted), Fujii Masao,
and Tom Lane, and with comments by various others.
Discussion: http://postgr.es/m/CA+TgmobMjnyBfNhGTKQEDbqXYE3_rXWpc4CM63fhyerNCes3mA@mail.gmail.com
Commit 7dbfea3c45 thought it could get
away with removing this, but Thomas Munro reports, on behalf of the
buildfarm, that it's still needed at least on Windows to avoid
compiler warnings.
The new function, heap_fetch_toast_slice, is shared between
toast_fetch_datum_slice and toast_fetch_datum, and does all the
work of scanning the TOAST table, fetching chunks, and storing
them into the space allocated for the result varlena.
As an incidental side effect, this allows toast_fetch_datum_slice
to perform the scan with only a single scankey if all chunks are
being fetched, which might have some tiny performance benefit.
Discussion: http://postgr.es/m/CA+TgmobBzxwFojJ0zV0Own3dr09y43hp+OzU2VW+nos4PMXWEg@mail.gmail.com
Tuple conversion support in tupconvert.c is able to convert rowtypes
between two relations, inner and outer, which are logically equivalent
but have a different ordering or even dropped columns (used mainly for
inheritance tree and partitions). This makes use of attribute mappings,
which are simple arrays made of AttrNumber elements with a length
matching the number of attributes of the outer relation. The length of
the attribute mapping has been treated as completely independent of the
mapping itself until now, making it easy to pass down an incorrect
mapping length.
This commit refactors the code related to attribute mappings and moves
it into an independent facility called attmap.c, extracted from
tupconvert.c. This merges the attribute mapping with its length,
avoiding to try to guess what is the length of a mapping to use as this
is computed once, when the map is built.
This will avoid mistakes like what has been fixed in dc816e58, which has
used an incorrect mapping length by matching it with the number of
attributes of an inner relation (a child partition) instead of an outer
relation (a partitioned table).
Author: Michael Paquier
Reviewed-by: Amit Langote
Discussion: https://postgr.es/m/20191121042556.GD153437@paquier.xyz
This patch allows building the local relmap cache for a subscribed
relation after processing pending invalidation messages and potential
relcache updates. Without this, the attributes in the local cache don't
tally with the updated relcache entry leading to invalid memory access.
Reported-by Jehan-Guillaume de Rorthais
Author: Jehan-Guillaume de Rorthais and Vignesh C
Reviewed-by: Amit Kapila
Backpatch-through: 10
Discussion: https://postgr.es/m/20191025175929.7e90dbf5@firost
This changes the routines in charge of recycling WAL segments past the
last redo LSN to not use anymore "RedoRecPtr" as a local variable, which
is also available in the context of the session as a static declaration,
replacing it with "lastredoptr". This confusion has been introduced by
d9fadbf, so backpatch down to v11 like the other commit.
Thanks to Tom Lane, Robert Haas, Alvaro Herrera, Mark Dilger and Kyotaro
Horiguchi for the input provided.
Author: Ranier Vilela
Discussion: https://postgr.es/m/MN2PR18MB2927F7B5F690065E1194B258E35D0@MN2PR18MB2927.namprd18.prod.outlook.com
Backpatch-through: 11
If CheckAttributeType() threw an error about the datatype of an
index expression column, it would report an empty column name,
which is pretty unhelpful and certainly not the intended behavior.
I (tgl) evidently broke this in commit cfc5008a5, by not noticing
that the column's attname was used above where I'd placed the
assignment of it.
In HEAD and v12, this is trivially fixable by moving up the
assignment of attname. Before v12 the code is a bit more messy;
to avoid doing substantial refactoring, I took the lazy way out
and just put in two copies of the assignment code.
Report and patch by Amit Langote. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/CA+HiwqFA+BGyBFimjiYXXMa2Hc3fcL0+OJOyzUNjhU4NCa_XXw@mail.gmail.com
Commit d5406dea25 used a slightly
novel, and wrong, approach to compute the length of the last
toast chunk. It worked fine unless the last chunk happened to
have the largest possible size.
Rework some of the checks for bad TOAST chunks to be a bit simpler
and easier to understand. These checks verify that (1) we get all
and only the chunk numbers we expect to see and (2) each chunk has
the expected size. However, the existing code was a bit hard to
understand, at least for me; try to make it clearer.
As part of that, have toast_fetch_datum_slice check the relationship
between endchunk and totalchunks only with an Assert() rather than
checking every chunk number against both values. There's no need to
check that relationship in production builds because it's not a
function of whether on-disk corruption is present; it's just a
question of whether the code does the right math.
Also, have toast_fetch_datum_slice() use ereport(ERROR) rather than
elog(ERROR). Commit fd6ec93bf8 made
the two functions inconsistent with each other.
Rename assorted variables for better clarity and consistency, and
move assorted variables from function scope to the function's main
loop. Remove a few variables that are used only once entirely.
Patch by me, reviewed by Peter Eisentraut.
Discussion: http://postgr.es/m/CA+TgmobBzxwFojJ0zV0Own3dr09y43hp+OzU2VW+nos4PMXWEg@mail.gmail.com
Where possible, share signal handler code and main loop interrupt
checking. This saves quite a bit of code and should simplify
maintenance, too.
This commit intends not to change the way anything works, even
though that might allow more code to be unified. It does unify
a bunch of individual variables into a ShutdownRequestPending
flag that has is now used by a bunch of different process types,
though.
Patch by me, reviewed by Andres Freund and Daniel Gustafsson.
Discussion: http://postgr.es/m/CA+TgmoZwDk=BguVDVa+qdA6SBKef=PKbaKDQALTC_9qoz1mJqg@mail.gmail.com
There seems to be no reason for every background process to have
its own flag indicating that a config-file reload is needed.
Instead, let's just use ConfigFilePending for that purpose
everywhere.
Patch by me, reviewed by Andres Freund and Daniel Gustafsson.
Discussion: http://postgr.es/m/CA+TgmoZwDk=BguVDVa+qdA6SBKef=PKbaKDQALTC_9qoz1mJqg@mail.gmail.com
Some auxiliary processes, as well as the autovacuum launcher,
have interrupt handling code directly in their main loops.
Try to abstract things a little better by moving it into
separate functions.
This doesn't make any functional difference, and leaves
in place relatively large differences among processes in how
interrupts are handled, but hopefully it at least makes it
easier to see the commonalities and differences across
process types.
Patch by me, reviewed by Andres Freund and Daniel Gustafsson.
Discussion: http://postgr.es/m/CA+TgmoZwDk=BguVDVa+qdA6SBKef=PKbaKDQALTC_9qoz1mJqg@mail.gmail.com
This Assert thought that an overflowed transaction can never get registered
for the group update. But that is not true, because even when the number
of children for a transaction got reduced, the overflow flag is not
changed. And, for group update, we only care about the current number of
children for a transaction that is being committed.
Based on comments by Andres Freund, remove a redundant Assert in
TransactionIdSetPageStatus as we already had a static Assert for the same
condition a few lines earlier.
Reported-by: Vignesh C
Author: Dilip Kumar
Reviewed-by: Amit Kapila
Backpatch-through: 11
Discussion: https://postgr.es/m/CAFiTN-s5=uJw-Z6JC9gcqtBSjXsrHnU63PXBrA=pnBjqnkm5UA@mail.gmail.com
force_parallel_mode = regress is supposed to force use of a Gather
node without having any impact on EXPLAIN output. But it failed to
accomplish that if both ANALYZE and VERBOSE are given, because that
enables per-worker output data that you wouldn't see if the Gather
hadn't been inserted. Improve the logic so that we suppress the
per-worker data too.
This allows putting the new test case added by commit 5935917ce
back into the originally intended form (cf. 776a2c887, 22864f6e0).
We can also get rid of a kluge in subselect.sql, which previously
had to clean up after force_parallel_mode's failure to do what it
said on the tin.
Discussion: https://postgr.es/m/18445.1576177309@sss.pgh.pa.us
recoveryDelayUntilTime was introduced by commit 36da3cfb45 as a global
because its method of operation was devilishly intrincate. Commit
c945af80cf removed all that complexity and could have turned it into a
local variable, but didn't. Do so now.
Discussion: https://postgr.es/m/20191213200751.GA10731@alvherre.pgsql
Reviewed-by: Michaël Paquier, Daniel Gustafsson
Commit a7ee7c8513 fixed a bug in GiST page split during index creation,
where we failed to re-find the position of a downlink after the page
containing it was split. However, that fix was incomplete; the other call
to gistinserttuples() in the same function needs to also clear
'downlinkoffnum'.
Fixes bug #16134 reported by Alexander Lakhin, for real this time. The
previous fix was enough to fix the crash with the reproducer script for
bug #16162, but the original script for #16134 was still crashing.
Backpatch to v12, like the previous incomplete fix.
Discussion: https://www.postgresql.org/message-id/d869f537-abe4-d2ea-0510-38cd053f5152%40gmail.com
The getpeereid() uses have so far been protected by HAVE_UNIX_SOCKETS,
so they didn't ever care about Windows support. But in anticipation
of Unix-domain socket support on Windows, that needs to be handled
differently.
Windows doesn't support getpeereid() at this time, so we use the
existing not-supported code path. We let configure do its usual thing
of picking up the replacement from libpgport, instead of the custom
overrides that it was doing before.
But then Windows doesn't have struct passwd, so this patch sprinkles
some additional #ifdef WIN32 around to make it work. This is similar
to existing code that deals with this issue.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/5974caea-1267-7708-40f2-6009a9d653b0@2ndquadrant.com
This has been introduced by c16dc1a since progress reporting for VACUUM
has been added. As this issue just causes some extra work and is
harmless, no backpatch is done.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20191213030831.GT2082@telsasoft.com
The RTE_RESULT simplification logic added by commit 4be058fe9 had a
flaw: it would collapse out a RTE_RESULT that is due to compute a
PlaceHolderVar, and reassign the PHV to the parent join level, even if
another input relation of the join contained a lateral reference to
the PHV. That can't work because the PHV would be computed too late.
In practice it led to failures of internal sanity checks later in
planning (either assertion failures or errors such as "failed to
construct the join relation").
To fix, add code to check for the presence of such PHVs in relevant
portions of the query tree. Notably, this required refactoring
range_table_walker so that a caller could ask to walk individual RTEs
not the whole list. (It might be a good idea to refactor
range_table_mutator in the same way, if only to keep those functions
looking similar; but I didn't do so here as it wasn't necessary for
the bug fix.)
This exercise also taught me that find_dependent_phvs(), as it stood,
could only safely be used on the entire Query, not on subtrees.
Adjust its API to reflect that; which in passing allows it to have
a fast path for the common case of no PHVs anywhere.
Per report from Will Leinweber. Back-patch to v12 where the bug
was introduced.
Discussion: https://postgr.es/m/CALLb-4xJMd4GZt2YCecMC95H-PafuWNKcmps4HLRx2NHNBfB4g@mail.gmail.com
When loading DH parameters used for the generation of ephemeral DH keys
in the backend, the code has never bothered releasing the memory used
for the DH information loaded from a file or from libpq's default. This
commit makes sure that the information is properly free()'d.
Note that as SSL parameters can be reloaded, this can cause an accumulation
of memory leaked. As the leak is minor, no backpatch is done.
Reported-by: Dmitry Uspenskiy
Discussion: https://postgr.es/m/16160-18367e56e9a28264@postgresql.org
The previous commit failed to consider that FileGetRawDesc() might
not return a valid fd, as discovered on the build farm. Switch to
using the File interface only.
Back-patch to 12, like the previous commit.
_mdfd_getseg() opens all segments up to the requested one. That
causes problems for mdsyncfiletag(), if mdunlinkfork() has
already unlinked other segment files. Open the file we want
directly by name instead, if it's not already open.
The consequence of this bug was a rare panic in the checkpointer,
made more likely if you saturated the sync request queue so that
the SYNC_FORGET_REQUEST messages for a given relation were more
likely to be absorbed in separate cycles by the checkpointer.
Back-patch to 12. Defect in commit 3eb77eba.
Author: Thomas Munro
Reported-by: Justin Pryzby
Discussion: https://postgr.es/m/20191119115759.GI30362%40telsasoft.com
The bug was similar to the one that was fixed in commit 22251686f0. When
we split page X and insert the downlink for the new page, the parent page
might also need to be split. When that happens, the downlink offset number
we remembered for X is no longer valid. We correctly called
gistFindCorrectParent() to re-find it, but gistFindCorrectParent() doesn't
do anything if the LSN of the page hasn't changed, and we stopped updating
LSNs during index build in commit 9155580fd5. The buggy codepath was taken
if the page was split into three or more pages, and inserting the downlink
caused the parent page to split. To fix, explicitly mark the downlink
offset number as invalid, to force gistFindCorrectParent() to re-find it.
Fixes bug #16134 reported by Alexander Lakhin, reported again as #16162 by
Andreas Kunert. Thanks to Jeff Janes, Tom Lane and Tomas Vondra for
debugging. Backpatch to v12, where we stopped WAL-logging during index
build.
Discussion: https://www.postgresql.org/message-id/16134-0423f729671dec64%40postgresql.org
Discussion: https://www.postgresql.org/message-id/16162-45d21b7b6c1a3105%40postgresql.org
The DTK_DOW/DTK_ISODOW and DTK_DOY switch cases in timestamp_part() and
timestamptz_part() contained calls of timestamp2tm() that were fully
redundant with the ones done just above the switch. This evidently crept
in during commit 258ee1b63, which relocated that code from another place
where the calls were indeed needed. Just delete the redundant calls.
I (tgl) noted that our test coverage of these functions left quite a
bit to be desired, so extend timestamp.sql and timestamptz.sql to
cover all the branches.
Back-patch to all supported branches, as the previous commit was.
There's no real issue here other than some wasted cycles in some
not-too-heavily-used code paths, but the test coverage seems valuable.
Report and patch by Li Japin; test case adjustments by me.
Discussion: https://postgr.es/m/SG2PR06MB37762CAE45DB0F6CA7001EA9B6550@SG2PR06MB3776.apcprd06.prod.outlook.com
This is made necessary by the fact that commit 6ef77cf46 added
AppendRelInfos to plan trees. I'd concluded that this extra code was
not necessary because we don't transmit that data to parallel workers
... but I forgot about -DWRITE_READ_PARSE_PLAN_TREES. Per buildfarm.
Previously, if the startup pruning logic proved that all child nodes
of an Append or MergeAppend could be pruned, we still kept one, just
to keep EXPLAIN from failing. The previous commit removed the
ruleutils.c limitation that required this kluge, so drop it. That
results in less-confusing EXPLAIN output, as per a complaint from
Yuzuko Hosoya.
David Rowley
Discussion: https://postgr.es/m/001001d4f44b$2a2cca50$7e865ef0$@lab.ntt.co.jp
This patch causes EXPLAIN to always assign a separate table alias to the
parent RTE of an append relation (inheritance set); before, such RTEs
were ignored if not actually scanned by the plan. Since the child RTEs
now always have that same alias to start with (cf. commit 55a1954da),
the net effect is that the parent RTE usually gets the alias used or
implied by the query text, and the children all get that alias with "_N"
appended. (The exception to "usually" is if there are duplicate aliases
in different subtrees of the original query; then some of those original
RTEs will also have "_N" appended.)
This results in more uniform output for partitioned-table plans than
we had before: the partitioned table itself gets the original alias,
and all child tables have aliases with "_N", rather than the previous
behavior where one of the children would get an alias without "_N".
The reason for giving the parent RTE an alias, even if it isn't scanned
by the plan, is that we now use the parent's alias to qualify Vars that
refer to an appendrel output column and appear above the Append or
MergeAppend that computes the appendrel. But below the append, Vars
refer to some one of the child relations, and are displayed that way.
This seems clearer than the old behavior where a Var that could carry
values from any child relation was displayed as if it referred to only
one of them.
While at it, change ruleutils.c so that the code paths used by EXPLAIN
deal in Plan trees not PlanState trees. This effectively reverts a
decision made in commit 1cc29fe7c, which seemed like a good idea at
the time to make ruleutils.c consistent with explain.c. However,
it's problematic because we'd really like to allow executor startup
pruning to remove all the children of an append node when possible,
leaving no child PlanState to resolve Vars against. (That's not done
here, but will be in the next patch.) This requires different handling
of subplans and initplans than before, but is otherwise a pretty
straightforward change.
Discussion: https://postgr.es/m/001001d4f44b$2a2cca50$7e865ef0$@lab.ntt.co.jp
This makes such log entries more useful, since the cause of the error
can be dependent on the parameter values.
Author: Alexey Bashtanov, Álvaro Herrera
Discussion: https://postgr.es/m/0146a67b-a22a-0519-9082-bc29756b93a2@imap.cc
Reviewed-by: Peter Eisentraut, Andres Freund, Tom Lane
Since its inception, our Windows signal emulation code has worked by
running a main signal thread that just watches for incoming signal
requests, and then spawns a new thread to handle each such request.
That design is meant for servers in which requests can take substantial
effort to process, and it's worth parallelizing the handling of
requests. But those assumptions are just bogus for our signal code.
It's not much more than pg_queue_signal(), which is cheap and can't
parallelize at all, plus we don't really expect lots of signals to
arrive at the same backend at once. More importantly, this approach
creates failure modes that we could do without: either inability to
spawn a new thread or inability to create a new pipe handle will risk
loss of signals. Hence, dispense with the separate per-signal threads
and just service each request in-line in the main signal thread. This
should be a bit faster (for the normal case of one signal at a time)
as well as more robust.
Patch by me; thanks to Andrew Dunstan for testing and Amit Kapila
for review.
Discussion: https://postgr.es/m/4412.1575748586@sss.pgh.pa.us
It was once possible to do ALTER TABLE ... SET STATISTICS on system
tables without allow_sytem_table_mods. This was changed apparently by
accident between PostgreSQL 9.1 and 9.2, but a code comment still
claimed this was possible. Without that functionality, having a
separate ATPrepSetStatistics() is useless, so use the generic
ATSimplePermissions() instead and move the remaining custom code into
ATExecSetStatistics().
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/cc8d2648-a0ec-7a86-13e5-db473484e19e%402ndquadrant.com
gcc-7 used with a sufficient optimization level complains about warnings
around do_to_timestamp() regarding the initialization and handling of
some of its variables. Recent commits 66c74f8 and d589f94 made things
made the interface more confusing, so document which variables are
always expected and initialize properly the optional ones when they are
set.
Author: Andrey Lepikhov, Michael Paquier
Discussion: https://postgr.es/m/a7e28b83-27b1-4e1c-c76b-4268c4b785bc@postgrespro.ru
This provides a mechanism to emit literal values in informative
messages, such as query parameters. The new code is more complex than
what it replaces, primarily because it wants to be more efficient.
It also has the (currently unused) additional optional capability of
specifying a maximum size to print.
The new function lives out of common/stringinfo.c so that frontend users
of that file need not pull in unnecessary multibyte-encoding support
code.
Author: Álvaro Herrera and Alexey Bashtanov, after a suggestion from Andres Freund
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/20190920203905.xkv5udsd5dxfs6tr@alap3.anarazel.de
AfterTriggerExecute() retrieves a fresh tuple or pair of tuples from a
tuplestore and then stores the tuple(s) in the passed-in slot(s) if
AFTER_TRIGGER_FDW_FETCH, while it uses the most-recently-retrieved
tuple(s) stored in the slot(s) if AFTER_TRIGGER_FDW_REUSE. This was
done correctly before 12, but commit ff11e7f4b broke it by mistakenly
clearing the tuple(s) stored in the slot(s) in that function, leading to
an assertion failure as reported in bug #16139 from Alexander Lakhin.
Also, fix some other issues with the aforementioned commit in passing:
* For tg_newslot, which is a slot added to the TriggerData struct by the
commit to store new updated tuples, it didn't ensure the slot was NULL
if there was no such tuple.
* The commit failed to update the documentation about the trigger
interface.
Author: Etsuro Fujita
Backpatch-through: 12
Discussion: https://postgr.es/m/16139-94f9ccf0db6119ec%40postgresql.org
pg_signal_dispatch_thread() responded to the client (signal sender)
and disconnected the pipe before actually setting the shared variables
that make the signal visible to the backend process's main thread.
In the worst case, it seems, effective delivery of the signal could be
postponed for as long as the machine has any other work to do.
To fix, just move the pg_queue_signal() call so that we do it before
responding to the client. This essentially makes pgkill() synchronous,
which is a stronger guarantee than we have on Unix. That may be
overkill, but on the other hand we have not seen comparable timing bugs
on any Unix platform.
While at it, add some comments to this sadly underdocumented code.
Problem diagnosis and fix by Amit Kapila; I just added the comments.
Back-patch to all supported versions, as it appears that this can cause
visible NOTIFY timing oddities on all of them, and there might be
other misbehavior due to slow delivery of other signals.
Discussion: https://postgr.es/m/32745.1575303812@sss.pgh.pa.us
When creating a uniqueness constraint using a pre-existing index,
we have always required that the index have the same properties you'd
get if you just let a new index get built. However, when collations
were added, we forgot to add the index's collation to that check.
It's hard to trip over this without intentionally trying to break it:
you'd have to explicitly specify a different collation in CREATE
INDEX, then convert it to a pkey or unique constraint. Still, if you
did that, pg_dump would emit a script that fails to reproduce the
index's collation. The main practical problem is that after a
pg_upgrade the index would be corrupt, because its actual physical
order wouldn't match what pg_index says. A more theoretical issue,
which is new as of v12, is that if you create the index with a
nondeterministic collation then it wouldn't be enforcing the normal
notion of uniqueness, causing the constraint to mean something
different from a normally-created constraint.
To fix, just add collation to the conditions checked for index
acceptability in ADD PRIMARY KEY/UNIQUE USING INDEX. We won't try
to clean up after anybody who's already created such a situation;
it seems improbable enough to not be worth the effort involved.
(If you do get into trouble, a REINDEX should be enough to fix it.)
In principle this is a long-standing bug, but I chose not to
back-patch --- the odds of causing trouble seem about as great
as the odds of preventing it, and both risks are very low anyway.
Per report from Alexey Bashtanov, though this is not his preferred
fix.
Discussion: https://postgr.es/m/b05ce36a-cefb-ca5e-b386-a400535b1c0b@imap.cc
Change default of ssl_min_protocol_version to TLSv1.2 (from TLSv1,
which means 1.0). Older versions are still supported, just not by
default.
TLS 1.0 is widely deprecated, and TLS 1.1 only slightly less so. All
OpenSSL versions that support TLS 1.1 also support TLS 1.2, so there
would be very little reason to, say, set the default to TLS 1.1
instead on grounds of better compatibility.
The test suite overrides this new setting, so it can still run with
older OpenSSL versions.
Discussion: https://www.postgresql.org/message-id/flat/b327f8df-da98-054d-0cc5-b76a857cfed9%402ndquadrant.com
Error messages referring to incorrect WAL segment names could have been
generated for a fsync() failure or when creating a new segment at the
end of recovery.
XLogFileNameP() is a wrapper routine able to build a palloc'd string for
a WAL segment name, which is used for error string generation. There
were several code paths where it gets called in a critical section,
where memory allocation is not allowed. This results in triggering
an assertion failure instead of generating the wanted error message.
Another, more annoying, problem is that if the allocation to generate
the WAL segment name fails on OOM, then the failure would be escalated
to a PANIC.
This removes the routine and all its callers are replaced with a logic
using a fixed-size buffer. This way, all the existing mistakes are
fixed and future ones are prevented.
Author: Masahiko Sawada
Reviewed-by: Michael Paquier, Álvaro Herrera
Discussion: https://postgr.es/m/CA+fd4k5gC9H4uoWMLg9K_QfNrnkkdEw+-AFveob9YX7z8JnKTA@mail.gmail.com
If an inheritance/partitioning parent table is assigned some column
alias names in the query, EXPLAIN mapped those aliases onto the
child tables' columns by physical position, resulting in bogus output
if a child table's columns aren't one-for-one with the parent's.
To fix, make expand_single_inheritance_child() generate a correctly
re-mapped column alias list, rather than just copying the parent
RTE's alias node. (We have to fill the alias field, not just
adjust the eref field, because ruleutils.c will ignore eref in
favor of looking at the real column names.)
This means that child tables will now always have alias fields in
plan rtables, where before they might not have. That results in
a rather substantial set of regression test output changes:
EXPLAIN will now always show child tables with aliases that match
the parent table (usually with "_N" appended for uniqueness).
But that seems like a net positive for understandability, since
the parent alias corresponds to something that actually appeared
in the original query, while the child table names didn't.
(Note that this does not change anything for cases where an explicit
table alias was written in the query for the parent table; it
just makes cases without such aliases behave similarly to that.)
Hence, while we could avoid these subsidiary changes if we made
inherit.c more complicated, we choose not to.
Discussion: https://postgr.es/m/12424.1575168015@sss.pgh.pa.us
This provides for cheaper mapping of child columns back to parent
columns. The one existing use-case in examine_simple_variable()
would hardly justify this by itself; but an upcoming bug fix will
make use of this array in a mainstream code path, and it seems
likely that we'll find other uses for it as we continue to build
out the partitioning infrastructure.
Discussion: https://postgr.es/m/12424.1575168015@sss.pgh.pa.us
We implement ON COMMIT DELETE ROWS by truncating tables marked that
way, which requires also truncating/rebuilding their indexes. But
RelationTruncateIndexes asks the relcache for up-to-date copies of any
index expressions, which may cause execution of eval_const_expressions
on them, which can result in actual execution of subexpressions.
This is a bad thing to have happening during ON COMMIT. Manuel Rigger
reported that use of a SQL function resulted in crashes due to
expectations that ActiveSnapshot would be set, which it isn't.
The most obvious fix perhaps would be to push a snapshot during
PreCommit_on_commit_actions, but I think that would just open the door
to more problems: CommitTransaction explicitly expects that no
user-defined code can be running at this point.
Fortunately, since we know that no tuples exist to be indexed, there
seems no need to use the real index expressions or predicates during
RelationTruncateIndexes. We can set up dummy index expressions
instead (we do need something that will expose the right data type,
as there are places that build index tupdescs based on this), and
just ignore predicates and exclusion constraints.
In a green field it'd likely be better to reimplement ON COMMIT DELETE
ROWS using the same "init fork" infrastructure used for unlogged
relations. That seems impractical without catalog changes though,
and even without that it'd be too big a change to back-patch.
So for now do it like this.
Per private report from Manuel Rigger. This has been broken forever,
so back-patch to all supported branches.
Make allow_system_table_mods settable at run time by superusers. It
was previously postmaster start only.
We don't want to make system catalog DDL wide-open, but there are
occasionally useful things to do like setting reloptions or statistics
on a busy system table, and blocking those doesn't help anyone. Also,
this enables the possibility of writing a test suite for this setting.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/8b00ea5e-28a7-88ba-e848-21528b632354%402ndquadrant.com
Previously, allow_system_table_mods allowed a non-superuser to do DML
on a system table without further permission checks. This has been
removed, as it was quite inconsistent with the rest of the meaning of
this setting. (Since allow_system_table_mods was previously only
accessible with a server restart, it is unlikely that anyone was using
this possibility.)
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/8b00ea5e-28a7-88ba-e848-21528b632354%402ndquadrant.com
When picking the best extended statistics object for a list of clauses,
it's not enough to look at attnums extracted from the clause list as a
whole. Consider for example this query with OR clauses:
SELECT * FROM t WHERE (t.a = 1) OR (t.b = 1) OR (t.c = 1)
with a statistics defined on columns (a,b). Relying on attnums extracted
from the whole OR clause, we'd consider the statistics usable. That does
not work, as we see the conditions as a single OR-clause, referencing an
attribute not covered by the statistic, leading to empty list of clauses
to be estimated using the statistics and an assert failure.
This changes choose_best_statistics to check which clauses are actually
covered, and only using attributes from the fully covered ones. For the
previous example this means the statistics object will not be considered
as compatible with the OR-clause.
Backpatch to 12, where MCVs were introduced. The issue does not affect
older versions because functional dependencies don't handle OR clauses.
Author: Tomas Vondra
Reviewed-by: Dean Rasheed
Reported-By: Manuel Rigger
Discussion: https://postgr.es/m/CA+u7OA7H5rcE2=8f263w4NZD6ipO_XOrYB816nuLXbmSTH9pQQ@mail.gmail.com
Backpatch-through: 12
The fix for CVE-2017-7484 disallowed use of pg_statistic data for
planning purposes if the user would not be able to select the associated
column and a non-leakproof function is to be applied to the statistics
values. That turns out to disable use of pg_statistic data in some
common cases involving inheritance/partitioning, where the user does
have permission to select from the parent table that was actually named
in the query, but not from a child table whose stats are needed. Since,
in non-corner cases, the user *can* select the child table's data via
the parent, this restriction is not actually useful from a security
standpoint. Improve the logic so that we also check the permissions of
the originally-named table, and allow access if select permission exists
for that.
When checking access to stats for a simple child column, we can map
the child column number back to the parent, and perform this test
exactly (including not allowing access if the child column isn't
exposed by the parent). For expression indexes, the current logic
just insists on whole-table select access, and this patch allows
access if the user can select the whole parent table. In principle,
if the child table has extra columns, this might allow access to
stats on columns the user can't read. In practice, it's unlikely
that the planner is going to do any stats calculations involving
expressions that are not visible to the query, so we'll ignore that
fine point for now. Perhaps someday we'll improve that logic to
detect exactly which columns are used by an expression index ...
but today is not that day.
Back-patch to v11. The issue was created in 9.2 and up by the
CVE-2017-7484 fix, but this patch depends on the append_rel_array[]
planner data structure which only exists in v11 and up. In
practice the issue is most urgent with partitioned tables, so
fixing v11 and later should satisfy much of the practical need.
Dilip Kumar and Amit Langote, with some kibitzing by me
Discussion: https://postgr.es/m/3876.1531261875@sss.pgh.pa.us
On some platforms, fsync() returns EBADFD when opening a file descriptor
with O_RDONLY (read-only), leading ultimately now to a PANIC to prevent
data corruption.
This commit adds a new sanity check in pg_fsync() based on fcntl() to
make sure that we don't repeat again mistakes with incorrectly-set file
descriptors so as problems are detected at an early stage. Without
that, such errors could only be detected after running Postgres on a
specific supported platform for the culprit code path, which could take
some time before being found. b8e19b93 was a fix for such a problem,
which got undetected for more than 5 years, and a586cc4b fixed another
similar issue.
Note that the new check added works as well when fsync=off is
configured, so as all regression tests would detect problems as long as
assertions are enabled. fcntl() being not available on Windows, the
new checks do not happen there.
Author: Michael Paquier
Reviewed-by: Mark Dilger
Discussion: https://postgr.es/m/20191009062640.GB21379@paquier.xyz
Revert part of commit 19df1702f5.
Early shutdown was added by that commit so that we could collect
statistics from workers, but unfortunately, it interacted badly with
rescans. The problem is that we ended up destroying the parallel context
which is required for rescans. This leads to rescans of a Limit node over
a Gather node to produce unpredictable results as it tries to access
destroyed parallel context. By reverting the early shutdown code, we
might lose statistics in some cases of Limit over Gather [Merge], but that
will require further study to fix.
Reported-by: Jerry Sievers
Diagnosed-by: Thomas Munro
Author: Amit Kapila, testcase by Vignesh C
Backpatch-through: 9.6
Discussion: https://postgr.es/m/87ims2amh6.fsf@jsievers.enova.com
AuxiliaryProcessMain does ProcSignalInit, so one might expect that
auxiliary processes would need to respond to SendProcSignal, but none
of the auxiliary processes do that. Change them to use
procsignal_sigusr1_handler instead of their own private handlers so
that they do. Besides seeming more correct, this is also less code. It
shouldn't make any functional difference right now because, as far as
we know, there are no current cases where SendProcSignal targets an
auxiliary process, but there are plans to change that in the future.
Andres Freund
Discussion: http://postgr.es/m/20181030051643.elbxjww5jjgnjaxg@alap3.anarazel.de
XLogReader, walsender and pg_waldump all had their own routines to read
data from WAL files to memory, with slightly different approaches
according to the particular conditions of each environment. There's a
lot of commonality, so we can refactor that into a single routine
WALRead in XLogReader, and move the differences to a separate (simpler)
callback that just opens the next WAL-segment. This results in a
clearer (ahem) code flow.
The error reporting needs are covered by filling in a new error-info
struct, WALReadError, and it's the caller's responsibility to act on it.
The backend has WALReadRaiseError() to do so.
We no longer ever need to seek in this interface; switch to using
pg_pread().
Author: Antonin Houska, with contributions from Álvaro Herrera
Reviewed-by: Michaël Paquier, Kyotaro Horiguchi
Discussion: https://postgr.es/m/14984.1554998742@spoje.net
"%ld" is not an acceptable format spec for int64 variables, though
it accidentally works on most non-Windows 64-bit platforms. Follow
the lead of commit 6a1cd8b92, and use "%lld" with an explicit cast
to long long. Per buildfarm.
This reworks the reloption parsing and build of a couple of index AMs by
creating new structures for each index AM's options. This split was
already done for BRIN, GIN and GiST (which actually has a fillfactor
parameter), but not for hash, B-tree and SPGiST which relied on
StdRdOptions due to an overlap with the default option set.
This saves a couple of bytes for rd_options in each relcache entry with
indexes making use of relation options, and brings more consistency
between all index AMs. While on it, add a couple of AssertMacro() calls
to make sure that utility macros to grab values of reloptions are used
with the expected index AM.
Author: Nikolay Shaplov
Reviewed-by: Amit Langote, Michael Paquier, Álvaro Herrera, Dent John
Discussion: https://postgr.es/m/4127670.gFlpRb6XCm@x200m
If LISTEN is the only action in a serializable-mode transaction,
and the session was not previously listening, and the notify queue
is not empty, predicate.c reported an assertion failure. That
happened because we'd acquire the transaction's initial snapshot
during PreCommit_Notify, which was called *after* predicate.c
expects any such snapshot to have been established.
To fix, just swap the order of the PreCommit_Notify and
PreCommit_CheckForSerializationFailure calls during CommitTransaction.
This will imply holding the notify-insertion lock slightly longer,
but the difference could only be meaningful in serializable mode,
which is an expensive option anyway.
It appears that this is just an assertion failure, with no
consequences in non-assert builds. A snapshot used only to scan
the notify queue could not have been involved in any serialization
conflicts, so there would be nothing for
PreCommit_CheckForSerializationFailure to do except assign it a
prepareSeqNo and set the SXACT_FLAG_PREPARED flag. And given no
conflicts, neither of those omissions affect the behavior of
ReleasePredicateLocks. This admittedly once-over-lightly analysis
is backed up by the lack of field reports of trouble.
Per report from Mark Dilger. The bug is old, so back-patch to all
supported branches; but the new test case only goes back to 9.6,
for lack of adequate isolationtester infrastructure before that.
Discussion: https://postgr.es/m/3ac7f397-4d5f-be8e-f354-440020675694@gmail.com
Discussion: https://postgr.es/m/13881.1574557302@sss.pgh.pa.us
This patch ensures that, if any notify messages were received during
a just-finished transaction, they get sent to the frontend just before
not just after the ReadyForQuery message. With libpq and other client
libraries that act similarly, this guarantees that the client will see
the notify messages as available as soon as it thinks the transaction
is done.
This probably makes no difference in practice, since in realistic
use-cases the application would have to cope with asynchronous
arrival of notify events anyhow. However, it makes it a lot easier
to build cross-session-notify test cases with stable behavior.
I'm a bit surprised now that we've not seen any buildfarm instability
with the test cases added by commit b10f40bf0. Tests that I intend
to add in an upcoming bug fix are definitely unstable without this.
Back-patch to 9.6, which is as far back as we can do NOTIFY testing
with the isolationtester infrastructure.
Discussion: https://postgr.es/m/13881.1574557302@sss.pgh.pa.us
This function wasn't touched in commit 51004c717, but that turns out
to be a bad idea, because its results now include any dead space
that exists in the NOTIFY queue on account of our being lazy about
advancing the queue tail. Notably, the isolation tests now fail
if run twice without a server restart between, because async-notify's
first test of the function will already show a positive value.
It seems likely that end users would be equally unhappy about the
result's instability. To fix, just make the function call
asyncQueueAdvanceTail before computing its result. That should end
in producing the same value as before, and it's hard to believe that
there's any practical use-case where pg_notification_queue_usage()
is called so often as to create a performance degradation, especially
compared to what we did before.
Out of paranoia, also mark this function parallel-restricted (it
was volatile, but parallel-safe by default, before). Although the
code seems to work fine when run in a parallel worker, that's outside
the design scope of async.c, and it's a bit scary to have intentional
side-effects happening in a parallel worker. There seems no plausible
use-case where it'd be important to try to parallelize this, so let's
not take any risk of introducing new bugs.
In passing, re-pgindent async.c and run reformat-dat-files on
pg_proc.dat, just because I'm a neatnik.
Discussion: https://postgr.es/m/13881.1574557302@sss.pgh.pa.us
All operations with acl permissions checks should have a corresponding hook
so that, for example, mandatory access control (MAC) may be enforced by an
extension. The command TRUNCATE is missing this hook, so add it. Patch by
Yuli Khodorkovskiy with some editorialization by me. Based on the discussion
not back-patched. A separate patch will exercise the hook in the sepgsql
extension.
Author: Yuli Khodorkovskiy
Reviewed-by: Joe Conway
Discussion: https://postgr.es/m/CAFL5wJcomybj1Xdw7qWmPJRpGuFukKgNrDb6uVBaCMgYS9dkaA%40mail.gmail.com
slot_modify_cstrings seriously abused the TupleTableSlot API by relying
on a slot's underlying data to stay valid across ExecClearTuple. Since
this abuse was also quite undocumented, it's little surprise that the
case got broken during the v12 slot rewrites. As reported in bug #16129
from Ondřej Jirman, this could lead to crashes or data corruption when
a logical replication subscriber processes a row update. Problems would
only arise if the subscriber's table contained columns of pass-by-ref
types that were not being copied from the publisher.
Fix by explicitly copying the datum/isnull arrays from the source slot
that the old row was in already. This ends up being about the same
thing that happened pre-v12, but hopefully in a less opaque and
fragile way.
We might've caught the problem sooner if there were any test cases
dealing with updates involving non-replicated or dropped columns.
Now there are.
Back-patch to v10 where this code came in. Even though the failure
does not manifest before v12, IMO this code is too fragile to leave
as-is. In any case we certainly want the additional test coverage.
Patch by me; thanks to Tomas Vondra for initial investigation.
Discussion: https://postgr.es/m/16129-a0c0f48e71741e5f@postgresql.org
While a self-referential view doesn't actually work, it's possible
to create one, and it turns out that this breaks some of the
information_schema views. Those views call relation_is_updatable(),
which neglected to consider the hazards of being recursive. In
older PG versions you get a "stack depth limit exceeded" error,
but since v10 it'd recurse to the point of stack overrun and crash,
because commit a4c35ea1c took out the expression_returns_set() call
that was incidentally checking the stack depth.
Since this function is only used by information_schema views, it
seems like it'd be better to return "not updatable" than suffer
an error. Hence, add tracking of what views we're examining,
in just the same way that the nearby fireRIRrules() code detects
self-referential views. I added a check_stack_depth() call too,
just to be defensive.
Per private report from Manuel Rigger. Back-patch to all
supported versions.
Previously DROP DATABASE generated as many XLOG_DBASE_DROP WAL records
as the number of tablespaces that the database to drop uses. This caused
the scans of shared_buffers as many times as the number of the tablespaces
during recovery because WAL replay of one XLOG_DBASE_DROP record needs
that full scan. This could make the recovery time longer especially
when shared_buffers is large.
This commit changes DROP DATABASE so that it generates only one
XLOG_DBASE_DROP record, and registers the information of all the tablespaces
into it. Then, WAL replay of XLOG_DBASE_DROP record needs full scan of
shared_buffers only once, and which may improve the recovery performance.
Author: Fujii Masao
Reviewed-by: Kirk Jamison, Simon Riggs
Discussion: https://postgr.es/m/CAHGQGwF8YwNH0ZaL+2wjZPkj+ji9UhC+Z4ScnG97WKtVY5L9iw@mail.gmail.com
This adds the statistics about transactions spilled to disk from
ReorderBuffer. Users can query the pg_stat_replication view to check
these stats.
Author: Tomas Vondra, with bug-fixes and minor changes by Dilip Kumar
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
Trying to use hypothetical indexes with BRIN currently fails when trying
to access a relation that does not exist when looking for the
statistics. With the current API, it is not possible to easily pass
a value for pages_per_range down to the hypothetical index, so this
makes use of the default value of BRIN_DEFAULT_PAGES_PER_RANGE, which
should be fine enough in most cases.
Being able to refine or enforce the hypothetical costs in more
optimistic ways would require more refactoring by filling in the
statistics when building IndexOptInfo in plancat.c. This would involve
ABI breakages around the costing routines, something not fit for stable
branches.
This is broken since 7e534ad, so backpatch down to v10.
Author: Julien Rouhaud, Heikki Linnakangas
Reviewed-by: Álvaro Herrera, Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/CAOBaU_ZH0LKEA8VFCocr6Lpte1ab0b6FpvgS0y4way+RPSXfYg@mail.gmail.com
Backpatch-through: 10
Make patternsel_common() select the comparison operators to use with
hardwired logic that matches pattern_prefix()'s new logic, eliminating
its dependencies on particular index opfamilies.
This shouldn't change any behavior, as it's just replacing runtime
operator lookups with the same values hard-wired. But it makes these
closely-related functions look more alike, and saving some runtime
syscache lookups is worth something.
Actually, it's not quite true that this is zero behavioral change:
when estimating for a column of type "name", the comparison constant
will be kept as "text" not coerced to "name". But that's more correct
anyway, and it allows additional simplification of the coercion logic,
again syncing this more closely with pattern_prefix().
Per consideration of a report from Manuel Rigger.
Discussion: https://postgr.es/m/CA+u7OA7nnGYy8rY0vdTe811NuA+Frr9nbcBO9u2Z+JxqNaud+g@mail.gmail.com
Historically, the planner's LIKE/regex index optimizations were only
carried out for specific index opfamilies. That's never been a great
idea from the standpoint of extensibility, but it didn't matter so
much as long as we had no practical way to extend such behaviors anyway.
With the addition of planner support functions, and in view of ongoing
work to support additional table and index AMs, it seems like a good
time to relax this.
Hence, recast the decisions in match_pattern_prefix() so that rather
than decide which operators to generate by looking at what the index
opfamily contains, we decide which operators to generate a-priori
and then see if the opfamily supports them. This is much more
defensible from a semantic standpoint anyway, since we know the
semantics of the chosen operators precisely, and we only need to
assume that the opfamily correctly implements operators it claims
to support.
The existing "pattern" opfamilies put a crimp in this approach, since
we need to select the pattern operators if we want those to work.
So we still have to special-case those opfamilies. But that seems
all right, since in view of the addition of collations, the pattern
opfamilies seem like a legacy hack that nobody will be building on.
The only immediate effect of this change, so far as the core code is
concerned, is that anchored LIKE/regex patterns can be mapped onto
BRIN index searches, and exact-match patterns can be mapped onto hash
indexes, not only btree and spgist indexes as before. That's not a
terribly exciting result, but it does fix an omission mentioned in
the ancient comments here.
Note: no catversion bump, even though this touches pg_operator.dat,
because it's only adding OID macros not changing the contents of
postgres.bki.
Per consideration of a report from Manuel Rigger.
Discussion: https://postgr.es/m/CA+u7OA7nnGYy8rY0vdTe811NuA+Frr9nbcBO9u2Z+JxqNaud+g@mail.gmail.com
The planner's optimization code for LIKE and regex operators could
error out with a complaint like "no = operator for opfamily NNN"
if someone created a binary-compatible index (for example, a
bpchar_ops index on a text column) on the LIKE's left argument.
This is a consequence of careless refactoring in commit 74dfe58a5.
The old code in match_special_index_operator only accepted specific
combinations of the pattern operator and the index opclass, thereby
indirectly guaranteeing that the opclass would have a comparison
operator with the same LHS input type as the pattern operator.
While moving the logic out to a planner support function, I simplified
that test in a way that no longer guarantees that. Really though we'd
like an altogether weaker dependency on the opclass, so rather than
put back exactly the old code, just allow lookup failure. I have in
mind now to rewrite this logic completely, but this is the minimum
change needed to fix the bug in v12.
Per report from Manuel Rigger. Back-patch to v12 where the mistake
came in.
Discussion: https://postgr.es/m/CA+u7OA7nnGYy8rY0vdTe811NuA+Frr9nbcBO9u2Z+JxqNaud+g@mail.gmail.com
By oversight 52ac6cd2d0 makes ginDeletePage() sets pd_prune_xid of page to be
deleted before entering the critical section. It appears that only versions 11
and later were affected by this oversight.
Backpatch-through: 11
We find GIN concurrency bugs from time to time. One of the problems here is
that concurrency of GIN isn't well-documented in README. So, it might be even
hard to distinguish design bugs from implementation bugs.
This commit revised concurrency section in GIN README providing more details.
Some examples are illustrated in ASCII art.
Also, this commit add the explanation of how is tuple layout in internal GIN
B-tree page different in comparison with nbtree.
Discussion: https://postgr.es/m/CAPpHfduXR_ywyaVN4%2BOYEGaw%3DcPLzWX6RxYLBncKw8de9vOkqw%40mail.gmail.com
Author: Alexander Korotkov
Reviewed-by: Peter Geoghegan
Backpatch-through: 9.4
Current GIN code appears to don't handle traversing to the deleted page via
downlink. This commit fixes that by stepping right from the delete page like
we do in nbtree.
This commit also fixes setting 'deleted' flag to the GIN pages. Now other page
flags are not erased once page is deleted. That helps to keep our assertions
true if we arrive deleted page via downlink.
Discussion: https://postgr.es/m/CAPpHfdvMvsw-NcE5bRS7R1BbvA4BxoDnVVjkXC5W0Czvy9LVrg%40mail.gmail.com
Author: Alexander Korotkov
Reviewed-by: Peter Geoghegan
Backpatch-through: 9.4
When ginDeletePage() is about to delete page it locks its left sibling to revise
the rightlink. So, it locks pages in right to left manner. Int he same time
ginStepRight() locks pages in left to right manner, and that could cause a
deadlock.
This commit makes ginScanToDelete() keep exclusive lock on left siblings of
currently investigated path. That elimites need to relock left sibling in
ginDeletePage(). Thus, deadlock with ginStepRight() can't happen anymore.
Reported-by: Chen Huajun
Discussion: https://postgr.es/m/5c332bd1.87b6.16d7c17aa98.Coremail.chjischj%40163.com
Author: Alexander Korotkov
Reviewed-by: Peter Geoghegan
Backpatch-through: 10
Instead of deciding to serialize a transaction merely based on the
number of changes in that xact (toplevel or subxact), this makes
the decisions based on amount of memory consumed by the changes.
The memory limit is defined by a new logical_decoding_work_mem GUC,
so for example we can do this
SET logical_decoding_work_mem = '128kB'
to reduce the memory usage of walsenders or set the higher value to
reduce disk writes. The minimum value is 64kB.
When adding a change to a transaction, we account for the size in
two places. Firstly, in the ReorderBuffer, which is then used to
decide if we reached the total memory limit. And secondly in the
transaction the change belongs to, so that we can pick the largest
transaction to evict (and serialize to disk).
We still use max_changes_in_memory when loading changes serialized
to disk. The trouble is we can't use the memory limit directly as
there might be multiple subxact serialized, we need to read all of
them but we don't know how many are there (and which subxact to
read first).
We do not serialize the ReorderBufferTXN entries, so if there is a
transaction with many subxacts, most memory may be in this type of
objects. Those records are not included in the memory accounting.
We also do not account for INTERNAL_TUPLECID changes, which are
kept in a separate list and not evicted from memory. Transactions
with many CTID changes may consume significant amounts of memory,
but we can't really do much about that.
The current eviction algorithm is very simple - the transaction is
picked merely by size, while it might be useful to also consider age
(LSN) of the changes for example. With the new Generational memory
allocator, evicting the oldest changes would make it more likely
the memory gets actually pfreed.
The logical_decoding_work_mem can be set in postgresql.conf, in which
case it serves as the default for all publishers on that instance.
Author: Tomas Vondra, with changes by Dilip Kumar and Amit Kapila
Reviewed-by: Dilip Kumar and Amit Kapila
Tested-By: Vignesh C
Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
Make it clear that _bt_pgaddtup() truncates the first data item on an
internal page because its key is supposed to be treated as minus
infinity within _bt_compare().
It turns out that commit e9f1c01b7 missed a case: we must print a
VALUES clause in long format if get_query_def is given a resultDesc
that would require the query's output column name(s) to be different
from what the bare VALUES clause would produce.
This applies in case an ALTER ... RENAME COLUMN has been done to
a view that formerly could be printed in simple format, as shown
in the added regression test case. It also explains bug #16119
from Dmitry Telpt, because it turns out that (unlike CREATE VIEW)
CREATE MATERIALIZED VIEW fails to apply any column aliases it's
given to the stored ON SELECT rule. So to get them to be printed,
we have to account for the resultDesc renaming. It might be worth
changing the matview code so that it creates the ON SELECT rule
with the correct aliases; but we'd still need these messy checks in
get_simple_values_rte to handle the case of a subsequent column
rename, so any such change would be just neatnik-ism not a bug fix.
Like the previous patch, back-patch to all supported branches.
Discussion: https://postgr.es/m/16119-e64823f30a45a754@postgresql.org
In detoast_attr_slice, VARSIZE_ANY was used to compute compressed length
of on-disk TOAST values. That's incorrect, because the varlena value may
be just a TOAST pointer, producing either bogus value or crashing.
This is likely why the code was crashing on big-endian machines before
540f316809 replaced the VARSIZE with VARSIZE_ANY, which however only
masked the issue.
Reported-by: Rushabh Lathia
Discussion: https://postgr.es/m/CAL-OGkthU9Gs7TZchf5OWaL-Gsi=hXqufTxKv9qpNG73d5na_g@mail.gmail.com
When estimating number of distinct groups, we failed to ignore system
attributes when matching the group expressions to mvdistinct stats,
causing failures like
ERROR: negative bitmapset member not allowed
Fix that by simply skipping anything that is not a regular attribute.
Backpatch to PostgreSQL 10, where the extended stats were introduced.
Bug: #16111
Reported-by: Tuomas Leikola
Author: Tomas Vondra
Backpatch-through: 10
Discussion: https://postgr.es/m/16111-687799584c3a7e73@postgresql.org
Call ExecShutdownNode() after ExecutePlan()'s loop, rather than at each
break. We had forgotten to do that in one case. The omission caused
intermittent "temporary file leak" warnings from multi-batch parallel
hash joins with a LIMIT clause.
Back-patch to 11. Though the problem exists in theory in earlier
parallel query releases, nothing really depended on it.
Author: Kyotaro Horiguchi
Reviewed-by: Thomas Munro, Amit Kapila
Discussion: https://postgr.es/m/20191111.212418.2222262873417235945.horikyota.ntt%40gmail.com
reloptions.h includes since ba748f7 a set of macros to handle reloption
types in a way similar to how parseRelOptions() works. They have never
been used in the core code, and we have more simple methods now to parse
and fill in rd_options for a given relation depending on its relkind, so
remove this interface to simplify things.
Per discussion between Amit Langote, Álvaro Herrera and me.
Discussion: https://postgr.es/m/CA+HiwqE6zbNO92az6pp5GiTw4tr-9rfCE0t84whQSP+YwSKjMQ@mail.gmail.com
Partitioned tables do not have relation options yet, but, similarly to
what's done for views which have their own parsing table, it could make
sense to introduce new parameters for some of the existing default ones
like fillfactor, autovacuum, etc. Splitting things has the advantage to
make the information stored in rd_options include only the necessary
information, reducing the amount of memory used for a relcache entry
with partitioned tables if new reloptions are introduced at this level.
Author: Nikolay Shaplov
Reviewed-by: Amit Langote, Michael Paquier
Discussion: https://postgr.es/m/1627387.Qykg9O6zpu@x200m
We should throw an error for indeterminate collation, but bpcharne()
was missing that logic, resulting in a much less user-friendly error
(either an assertion failure or "cache lookup failed for collation 0").
Per report from Manuel Rigger. Back-patch to v12 where the mistake
came in, evidently in commit 5e1963fb7. (Before non-deterministic
collations, this function wasn't collation sensitive.)
Discussion: https://postgr.es/m/CA+u7OA4HOjtymxAbuGNh4-X_2R0Lw5n01tzvP8E5-i-2gQXYWA@mail.gmail.com
This gets rid of our former behavior of forcibly downcasing
the postmaster's hostname list and truncating the elements to
NAMEDATALEN. In principle, DNS hostnames are case-insensitive
so the first behavior should be harmless, and server hostnames
are seldom long enough for the second behavior to be an issue.
But it's still dubious, and an easy fix is available: just use
SplitGUCList instead.
AFAICT, all other SplitIdentifierString calls in the backend are
OK: either the items actually are SQL identifiers, or they are
keywords that are short and case-insensitive.
Per thinking about bug #16106. While this has been wrong for
a very long time, the lack of field complaints means there's
little reason to back-patch.
Discussion: https://postgr.es/m/16106-7d319e4295d08e70@postgresql.org
Commit 6b76f1bb5 changed all the RADIUS auth parameters to be lists
rather than single values. But its use of SplitIdentifierString
to parse the list format was not very carefully thought through,
because that function thinks it's parsing SQL identifiers, which
means it will (a) downcase the strings and (b) truncate them to
be shorter than NAMEDATALEN. While downcasing should be harmless
for the server names and ports, it's just wrong for the shared
secrets, and probably for the NAS Identifier strings as well.
The truncation aspect is at least potentially a problem too,
though typical values for these parameters would fit in 63 bytes.
Fortunately, we now have a function SplitGUCList that is exactly
the same except for not doing the two unwanted things, so fixing
this is a trivial matter of calling that function instead.
While here, improve the documentation to show how to double-quote
the parameter values. I failed to resist the temptation to do
some copy-editing as well.
Report and patch from Marcos David (bug #16106); doc changes by me.
Back-patch to v10 where the aforesaid commit came in, since this is
arguably a regression from our previous behavior with RADIUS auth.
Discussion: https://postgr.es/m/16106-7d319e4295d08e70@postgresql.org
The TableFunc node (i.e., XMLTABLE) includes type and collation OIDs
that might not be referenced anywhere else in the expression tree,
so they need to be accounted for when extracting dependencies.
Fortunately, the practical effects of this are limited, since
(a) it's somewhat unlikely that people would be extracting
columns of non-builtin types from an XML document, and (b)
in many scenarios, the query would contain other references
to such types, or functions depending on them. However, it's
not hard to construct examples wherein the existing code lets
one drop a type used in XMLTABLE and thereby break a view.
This is evidently an original oversight in the XMLTABLE patch,
so back-patch to v10 where that came in.
Discussion: https://postgr.es/m/18427.1573508501@sss.pgh.pa.us
This commit changes xact_desc() so that it reports the detail information about
PREPARE TRANSACTION record, like GID (global transaction identifier),
timestamp at prepare transaction, delete-on-abort/commit relations,
XID of subtransactions, and invalidation messages. These are helpful
when diagnosing 2PC-related troubles.
Author: Fujii Masao
Reviewed-by: Michael Paquier, Andrey Lepikhov, Kyotaro Horiguchi, Julien Rouhaud, Alvaro Herrera
Discussion: https://postgr.es/m/CAHGQGwEvhASad4JJnCv=0dW2TJypZgW_Vpb-oZik2a3utCqcrA@mail.gmail.com
This new option terminates the other sessions connected to the target
database and then drop it. To terminate other sessions, the current user
must have desired permissions (same as pg_terminate_backend()). We don't
allow to terminate the sessions if prepared transactions, active logical
replication slots or subscriptions are present in the target database.
Author: Pavel Stehule with changes by me
Reviewed-by: Dilip Kumar, Vignesh C, Ibrar Ahmed, Anthony Nowocien,
Ryan Lambert and Amit Kapila
Discussion: https://postgr.es/m/CAP_rwwmLJJbn70vLOZFpxGw3XD7nLB_7+NKz46H5EOO2k5H7OQ@mail.gmail.com
It is pointless to show in those views auxiliary processes that don't
open network connections.
A small incompatibility is that anybody joining pg_stat_activity and
pg_stat_ssl/pg_stat_gssapi will have to use a left join if they want to
see such auxiliary processes.
Author: Euler Taveira
Discussion: https://postgr.es/m/20190904151535.GA29108@alvherre.pgsql
An upcoming patch that adds deduplication to the nbtree AM will rely on
_bt_keep_natts_fast() understanding that differences in TOAST input
state can never affect its answer. In particular, two opclass-equal
datums (with opclasses deemed safe for deduplication) should never be
treated as unequal by _bt_keep_natts_fast() due to TOAST input
differences.
This also seems like a good idea on general principle. nbtsplitloc.c
will now occasionally make better decisions about where to split a leaf
page. The behavior of _bt_keep_natts_fast() is now somewhat closer to
the behavior of _bt_keep_natts().
Discussion: https://postgr.es/m/CAH2-Wzn3Ee49Gmxb7V1VJ3-AC8fWn-Fr8pfWQebHe8rYRxt5OQ@mail.gmail.com
Bring datum_image_eq() in line with datumIsEqual() by adding support for
comparing cstring datums.
An upcoming patch that adds deduplication to the nbtree AM will use
datum_image_eq(). datum_image_eq() will need to work with all datatypes
that can be used as the storage type of a B-Tree index column, including
cstring. (cstring is used as the storage type for columns of type
"name" as a space-saving optimization.)
Discussion: https://postgr.es/m/CAH2-Wzn3Ee49Gmxb7V1VJ3-AC8fWn-Fr8pfWQebHe8rYRxt5OQ@mail.gmail.com
This completes the task begun in commit 1408d5d86, to synchronize
ECPG's exported definitions with the definition of bool used by
c.h (and, therefore, the one actually in use in the ECPG library).
On practically all modern platforms, ecpglib.h will now just
include <stdbool.h>, which should surprise nobody anymore.
That removes a header-inclusion-order hazard for ECPG clients,
who previously might get build failures or unexpected behavior
depending on whether they'd included <stdbool.h> themselves,
and if so, whether before or after ecpglib.h.
On platforms where sizeof(_Bool) is not 1 (only old PPC-based
Mac systems, as far as I know), things are still messy, as
inclusion of <stdbool.h> could still break ECPG client code.
There doesn't seem to be any clean fix for that, and given the
probably-negligible population of users who would care anymore,
it's not clear we should go far out of our way to cope with it.
This change at least fixes some header-inclusion-order hazards
for our own code, since c.h and ecpglib.h previously disagreed
on whether bool should be char or unsigned char.
To implement this with minimal invasion of ECPG client namespace,
move the choice of whether to rely on <stdbool.h> into configure,
and have it export a configuration symbol PG_USE_STDBOOL.
ecpglib.h no longer exports definitions for TRUE and FALSE,
only their lowercase brethren. We could undo that if we get
push-back about it.
Ideally we'd back-patch this as far as v11, which is where c.h
started to rely on <stdbool.h>. But the odds of creating problems
for formerly-working ECPG client code seem about as large as the
odds of fixing any non-working cases, so we'll just do this in HEAD.
Discussion: https://postgr.es/m/CAA4eK1LmaKO7Du9M9Lo=kxGU8sB6aL8fa3sF6z6d5yYYVe3BuQ@mail.gmail.com
PredicateLockTuple() has a fast exit if tuple was written by the current
transaction, as in that case it already has a lock. This check can be
performed using TransactionIdIsCurrentTransactionId() instead of
SubTransGetTopmostTransaction(), to avoid any chance of having to hit the
disk.
Author: Ashwin Agrawal, based on a suggestion from Andres Freund
Reviewed-by: Thomas Munro
Discussion: https://postgr.es/m/CALfoeiv0k3hkEb3Oqk%3DziWqtyk2Jys1UOK5hwRBNeANT_yX%2Bng%40mail.gmail.com
If the passed in xid is the current top transaction, we can do a fast
check and exit early. This should work well for the current heap but
also works very well for proposed AMs that don't use a separate xid
for subtransactions.
Author: Ashwin Agrawal, based on a suggestion from Andres Freund
Reviewed-by: Thomas Munro
Discussion: https://postgr.es/m/CALfoeiv0k3hkEb3Oqk%3DziWqtyk2Jys1UOK5hwRBNeANT_yX%2Bng%40mail.gmail.com
This happens when we add a replica identity column on a subscriber
that does not yet exist on the publisher, according to the mapping
maintained by the subscriber. Code that checks whether the target
relation on the subscriber is updatable would check the replica
identity attribute bitmap with a column number -1, which would result
in an error. To fix, skip such columns in the bitmap lookup and
consider the relation not updatable. The result is consistent with
the rule that the replica identity columns on the subscriber must be a
subset of those on the publisher, since if the column doesn't exist on
the publisher, the column set on the subscriber can't be a subset.
Reported-by: Tim Clarke <tim.clarke@minerva.info>
Analyzed-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Discussion: https://www.postgresql.org/message-id/flat/a9139c29-7ddd-973b-aa7f-71fed9c38d75%40minerva.info
Add some support for automatically showing backtraces in certain error
situations in the server. Backtraces are shown on assertion failure;
also, a new setting backtrace_functions can be set to a list of C
function names, and all ereport()s and elog()s from the mentioned
functions will have backtraces generated. Finally, the function
errbacktrace() can be manually added to an ereport() call to generate a
backtrace for that call.
Authors: Peter Eisentraut, Álvaro Herrera
Discussion: https://postgr.es/m//5f48cb47-bf1e-05b6-7aae-3bf2cd01586d@2ndquadrant.com
Discussion: https://postgr.es/m/CAMsr+YGL+yfWE=JvbUbnpWtrRZNey7hJ07+zT4bYJdVp4Szdrg@mail.gmail.com
nbtree index builds once stashed the "minimum key" for a page, which was
used as the basis of the pivot tuple that gets placed in the next level
up (i.e. the tuple that stores the downlink to the page in question).
It doesn't quite work that way anymore, so the "minimum key" terminology
now seems misleading (these days the minimum key is actually a straight
copy of the high key from the left sibling, which is a distinct thing in
subtle but important ways). Rename this concept to "low key". This
name is a lot clearer given that there is now a sharp distinction
between pivot and non-pivot tuples. Also remove comments that describe
obsolete details about how the minimum key concept used to work.
Rather than generating the minus infinity item for the leftmost page on
a level by copying the new item and truncating that copy, simply
allocate a small buffer. The old approach confusingly created the
impression that the new item had some kind of significance. This was
another artifact of how things used to work before commits 8224de4f and
dd299df8.
SET CONSTRAINTS ... DEFERRED failed on partitioned tables, because of a
sanity check that ensures that the affected constraints have triggers.
On partitioned tables, the triggers are in the leaf partitions, not in
the partitioned relations themselves, so the sanity check fails.
Removing the sanity check solves the problem, because the code needed to
support the case is already there.
Backpatch to 11.
Note: deferred unique constraints are not affected by this bug, because
they do have triggers in the parent partitioned table. I did not add a
test for this scenario.
Discussion: https://postgr.es/m/20191105212915.GA11324@alvherre.pgsql
This patch adopts the overflow check logic introduced by commit cbdb8b4c0
into two more places. interval_mul() failed to notice if it computed a
new microseconds value that was one more than INT64_MAX, and pgbench's
double-to-int64 logic had the same sorts of edge-case problems that
cbdb8b4c0 fixed in the core code.
To make this easier to get right in future, put the guts of the checks
into new macros in c.h, and add commentary about how to use the macros
correctly.
Back-patch to all supported branches, as we did with the previous fix.
Yuya Watari
Discussion: https://postgr.es/m/CAJ2pMkbkkFw2hb9Qb1Zj8d06EhWAQXFLy73St4qWv6aX=vqnjw@mail.gmail.com
If there is the WAL page that the continuation WAL record just fits within
(i.e., the continuation record ends just at the end of the page) and
the LSN in such page is specified with -s option, previously pg_waldump
caused an assertion failure. The cause of this assertion failure was that
XLogFindNextRecord() that pg_waldump -s calls mistakenly handled
such special WAL page.
This commit changes XLogFindNextRecord() so that it can handle
such WAL page correctly.
Back-patch to all supported versions.
Author: Andrey Lepikhov
Reviewed-by: Fujii Masao, Michael Paquier
Discussion: https://postgr.es/m/99303554-5dd5-06e6-f943-b3005ccd6edd@postgrespro.ru
SPI gets used to build a list of relation OIDs for XML object
generation, and one code path building a list uses SPI_execute() without
looking at errors it produces. So fix that.
Author: Mark Dilger
Reviewed-by: Michael Paquier, Pavel Stehule
Discussion: https://postgr.es/m/17d30445-4862-7917-170f-84328dcd292d@gmail.com
This allows logging a sample of statements, without incurring excessive
log traffic (which may impact performance). This can be useful when
analyzing workloads with lots of short queries.
The sampling is configured using two new GUC parameters:
* log_min_duration_sample - minimum required statement duration
* log_statement_sample_rate - sample rate (0.0 - 1.0)
Only statements with duration exceeding log_min_duration_sample are
considered for sampling. To enable sampling, both those GUCs have to
be set correctly.
The existing log_min_duration_statement GUC has a higher priority, i.e.
statements with duration exceeding log_min_duration_statement will be
always logged, irrespectedly of how the sampling is configured. This
means only configurations
log_min_duration_sample < log_min_duration_statement
do actually sample the statements, instead of logging everything.
Author: Adrien Nayrat
Reviewed-by: David Rowley, Vik Fearing, Tomas Vondra
Discussion: https://postgr.es/m/bbe0a1a8-a8f7-3be2-155a-888e661cc06c@anayrat.info
Avoid creating transiently-inconsistent slot states where possible,
by not setting TTS_FLAG_SHOULDFREE until after the slot actually has
a free'able tuple pointer, and by making sure that we reset tts_nvalid
and related derived state before we replace the tuple contents. This
would only matter if something were to examine the slot after we'd
suffered some kind of error (e.g. out of memory) while manipulating
the slot. We typically don't do that, so these changes might just be
cosmetic --- but even if so, it seems like good future-proofing.
Also remove some redundant Asserts, and add a couple for consistency.
Back-patch to v12 where all this code was rewritten.
Discussion: https://postgr.es/m/16095-c3ff2e5283b8dba5@postgresql.org
Since commit d26a810eb, we've defined bool as being either _Bool from
<stdbool.h>, or "unsigned char"; but that commit overlooked the fact
that probes.d has "#define bool char". For consistency, make it say
"unsigned char" instead. This should be strictly a cosmetic change,
but it seems best to be in sync.
Formally, in the now-normal case where we're using <stdbool.h>, it'd
be better to write "#define bool _Bool". However, then we'd need
some build infrastructure to inject that configuration choice into
probes.d, and it doesn't seem worth the trouble. We only use
<stdbool.h> if sizeof(_Bool) is 1, so having DTrace think that
bool parameters are "unsigned char" should be close enough.
Back-patch to v12 where d26a810eb came in.
Discussion: https://postgr.es/m/CAA4eK1LmaKO7Du9M9Lo=kxGU8sB6aL8fa3sF6z6d5yYYVe3BuQ@mail.gmail.com
When sending data for logical decoding using the streaming replication
protocol via a WAL sender, the timestamp of the sent write message is
allocated at the beginning of the message when preparing for the write,
and actually computed when the write message is ready to be sent.
The timestamp was getting computed after sending the message. This
impacts anything using logical decoding, causing for example logical
replication to report mostly NULL for last_msg_send_time in
pg_stat_subscription.
This commit makes sure that the timestamp is computed before sending the
message. This is wrong since 5a991ef, so backpatch down to 9.4.
Author: Jeff Janes
Discussion: https://postgr.es/m/CAMkU=1z=WMn8jt7iEdC5sYNaPgAgOASb_OW5JYv-vMdYaJSL-w@mail.gmail.com
Backpatch-through: 9.4
WindowAgg will potentially store large numbers of input rows into
tuplestores to allow access to other rows in the frame. If the input
is coming via an explicit Sort node, then unneeded columns will
already have been discarded (since Sort requests a small tlist); but
there are idioms like COUNT(*) OVER () that result in the input not
being sorted at all, and cases where the input is being sorted by some
means other than a Sort; if we don't request a small tlist, then
WindowAgg's storage requirement is inflated by the unneeded columns.
Backpatch back to 9.6, where the current tlist handling was added.
(Prior to that, WindowAgg would always use a small tlist.)
Discussion: https://postgr.es/m/87a7ator8n.fsf@news-spur.riddles.org.uk
Previously ALTER MATERIALIZED VIEW / FOREIGN TABLE ... RENAME COLUMN ...
returned "ALTER TABLE" as a command tag. This commit fixes them so that
they return "ALTER MATERIALIZED VIEW" and "ALTER FOREIGN TABLE" as
command tags, respectively.
This issue exists in all supported versions, but we don't back-patch this
because it's not enough of a bug to justify taking any compatibility risks for.
Otherwise, the back-patch would cause minor version update to break,
for example, the existing event trigger functions using TG_TAG.
Author: Fujii Masao
Reviewed-by: Ibrar Ahmed
Discussion: https://postgr.es/m/CAHGQGwGUaC03FFdTFoHsCuDrrNvFvNVQ6xyd40==P25WvuBJjg@mail.gmail.com
There's plenty places in frontend code that could benefit from a
string buffer implementation. Some because it yields simpler and
faster code, and some others because of the desire to share code
between backend and frontend.
While there is a string buffer implementation available to frontend
code, libpq's PQExpBuffer, it is clunkier than stringinfo, it
introduces a libpq dependency, doesn't allow for sharing between
frontend and backend code, and has a higher API/ABI stability
requirement due to being exposed via libpq.
Therefore it seems best to just making StringInfo being usable by
frontend code. There's not much to do for that, except for rewriting
two subsequent elog/ereport calls into others types of error
reporting, and deciding on a maximum string length.
For the maximum string size I decided to privately define MaxAllocSize
to the same value as used in the backend. It seems likely that we'll
want to reconsider this for both backend and frontend code in the not
too far away future.
For now I've left stringinfo.h in lib/, rather than common/, to reduce
the likelihood of unnecessary breakage. We could alternatively decide
to provide a redirecting stringinfo.h in lib/, or just not provide
compatibility.
Author: Andres Freund
Reviewed-By: Kyotaro Horiguchi, Daniel Gustafsson
Discussion: https://postgr.es/m/20190920051857.2fhnvhvx4qdddviz@alap3.anarazel.de
When maintaining or merging patches, one of the most common sources
for conflicts are the list of objects in makefiles. Especially when
the split across lines has been changed on both sides, which is
somewhat common due to attempting to stay below 80 columns, those
conflicts are unnecessarily laborious to resolve.
By splitting, and alphabetically sorting, OBJS style lines into one
object per line, conflicts should be less frequent, and easier to
resolve when they still occur.
Author: Andres Freund
Discussion: https://postgr.es/m/20191029200901.vww4idgcxv74cwes@alap3.anarazel.de
For a long time (since commit aed378e8d) we have had a policy to log
nothing about a connection if the client disconnects when challenged
for a password. This is because libpq-using clients will typically
do that, and then come back for a new connection attempt once they've
collected a password from their user, so that logging the abandoned
connection attempt will just result in log spam. However, this did
not work well for PAM authentication: the bottom-level function
pam_passwd_conv_proc() was on board with it, but we logged messages
at higher levels anyway, for lack of any reporting mechanism.
Add a flag and tweak the logic so that the case is silent, as it is
for other password-using auth mechanisms.
Per complaint from Yoann La Cancellera. It's been like this for awhile,
so back-patch to all supported branches.
Discussion: https://postgr.es/m/CACP=ajbrFFYUrLyJBLV8=q+eNCapa1xDEyvXhMoYrNphs-xqPw@mail.gmail.com
get_relkind_objtype, and hence get_object_type, failed when applied to a
toast table. This is not a good thing, because it prevents reporting of
perfectly legitimate permissions errors. (At present, these functions
are in fact *only* used to determine the ObjectType argument for
acl_error() calls.) It seems best to have them fall back to returning
OBJECT_TABLE in every case where they can't determine an object type
for a pg_class entry, so do that.
In passing, make some edits to alter.c to make it more obvious that
those calls of get_object_type() are used only for error reporting.
This might save a few cycles in the non-error code path, too.
Back-patch to v11 where this issue originated.
John Hsu, Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/C652D3DF-2B0C-4128-9420-FB5379F6B1E4@amazon.com
Commit d25ea0127 got rid of what I thought were entirely unnecessary
derived child expressions in EquivalenceClasses for EC members that
mention multiple baserels. But it turns out that some of the child
expressions that code created are necessary for partitionwise joins,
else we fail to find matching pathkeys for Sort nodes. (This happens
only for certain shapes of the resulting plan; it may be that
partitionwise aggregation is also necessary to show the failure,
though I'm not sure of that.)
Reverting that commit entirely would be quite painful performance-wise
for large partition sets. So instead, add code that explicitly
generates child expressions that match only partitionwise child join
rels we have actually generated.
Per report from Justin Pryzby. (Amit Langote noticed the problem
earlier, though it's not clear if he recognized then that it could
result in a planner error, not merely failure to exploit partitionwise
join, in the code as-committed.) Back-patch to v12 where commit
d25ea0127 came in.
Amit Langote, with lots of kibitzing from me
Discussion: https://postgr.es/m/CA+HiwqG2WVUGmLJqtR0tPFhniO=H=9qQ+Z3L_ZC+Y3-EVQHFGg@mail.gmail.com
Discussion: https://postgr.es/m/20191011143703.GN10470@telsasoft.com
Historically, the code to build relation options has been shaped the
same way in multiple code paths by using a set of datums in input with
the options parsed with a static table which is then filled with the
option values. This introduces a new common routine in reloptions.c to
do most of the legwork for the in-core code paths.
Author: Amit Langote
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/CA+HiwqGsoSn_uTPPYT19WrtR7oYpYtv4CdS0xuedTKiHHWuk_g@mail.gmail.com
As the code stands, nEntries counts the number of ginEntryInsert()
calls, so that's what you end up with at the end of a GIN index build.
However, ginvacuumcleanup() recomputes nEntries as the number of
surviving leaf tuples, and that's generally consistent with the way that
gincostestimate() uses the value. So let's clearly define nEntries
as the number of leaf tuples, and therefore adjust ginEntryInsert() to
increment it only when we make a new one, not when we add TIDs into an
existing tuple or posting tree.
In practice this inconsistency probably has little impact, so I don't
feel a need to back-patch.
Insung Moon and Keisuke Kuroda
Discussion: https://postgr.es/m/CAEMmqBuH_O-oXL+3_ArQ6F5cJ7kXVow2SGQB3HRacku_T+xkmA@mail.gmail.com
Rearrange the logic in record_image_cmp() and datum_image_eq() to
error out on unexpected typlens (either not supported there or
completely invalid due to corruption). Barring corruption, this is
not possible today but it seems more future-proof and robust to fix
this.
Reported-by: Peter Geoghegan <pg@bowt.ie>
Commit 8af1624e3 introduced a warning about possibly returning
without a value, on compilers that don't realize that ereport(ERROR)
doesn't return. Tweak the code to avoid that.
Per buildfarm. Back-patch to 9.6, like the aforesaid commit.
Using incorrect, or just mismatched, dictionary and affix files
could result in a crash, due to failure to cross-check offsets
obtained from the file. Add necessary validation, as well as
some Asserts for future-proofing.
Per bug #16050 from Alexander Lakhin. Back-patch to 9.6 where the
problem was introduced.
Arthur Zakirov, per initial investigation by Tomas Vondra
Discussion: https://postgr.es/m/16050-024ae722464ab604@postgresql.org
Discussion: https://postgr.es/m/20191013012610.2p2fp3zzpoav7jzf@development
When using CREATE TABLE for a new partition, the partitioned indexes of
the parent are created automatically in a fashion similar to LIKE
INDEXES. The new partition and its parent use a mapping for attribute
numbers for this operation, and while the mapping was correctly built,
its length was defined as the number of attributes of the newly-created
child, and not the parent. If the parent includes dropped columns, this
could cause failures.
This is wrong since 8b08f7d which has introduced the concept of
partitioned indexes, so backpatch down to 11.
Reported-by: Wyatt Alt
Author: Michael Paquier
Reviewed-by: Amit Langote
Discussion: https://postgr.es/m/CAGem3qCcRmhbs4jYMkenYNfP2kEusDXvTfw-q+eOhM0zTceG-g@mail.gmail.com
Backpatch-through: 11
A couple of routines assume that the LWLock SyncRepLock needs to be
taken, so add a couple of assertions to be sure of that. Also, when
waiting for a given LSN at transaction commit, the code implied that the
syncrep queue cleanup happens while holding interrupts, but the code
never checked after that.
Author: Michael Paquier
Reviewed-by: Fujii Masao, Kyotaro Horiguchi, Dongming Liu
Discussion: https://postgr.es/m/a0806273-8bbb-43b3-bbe1-c45a58f6ae21.lingce.ldm@alibaba-inc.com
When a backend exits, it gets deleted from the syncrep queue if present.
The queue was checked without SyncRepLock taken in exclusive mode, so it
would have been possible for a backend to remove itself after a WAL
sender already did the job. Fix this issue based on a suggestion from
Fujii Masao, by first checking the queue without the lock. Then, if the
backend is present in the queue, take the lock and perform an additional
lookup check before doing the element deletion.
Author: Dongming Liu
Reviewed-by: Kyotaro Horiguchi, Fujii Masao, Michael Paquier
Discussion: https://postgr.es/m/a0806273-8bbb-43b3-bbe1-c45a58f6ae21.lingce.ldm@alibaba-inc.com
Backpatch-through: 9.4
This gives an alternative way of catching exceptions, for the common
case where the cleanup code is the same in the error and non-error
cases. So instead of
PG_TRY();
{
... code that might throw ereport(ERROR) ...
}
PG_CATCH();
{
cleanup();
PG_RE_THROW();
}
PG_END_TRY();
cleanup();
one can write
PG_TRY();
{
... code that might throw ereport(ERROR) ...
}
PG_FINALLY();
{
cleanup();
}
PG_END_TRY();
Discussion: https://www.postgresql.org/message-id/flat/95a822c3-728b-af0e-d7e5-71890507ae0c%402ndquadrant.com
IDENT_USERNAME_MAX is the maximum length of the information returned
by an ident server, per RFC 1413. Using it as the buffer size in peer
authentication is inappropriate. It was done here because of the
historical relationship between peer and ident authentication. To
reduce confusion between the two authenticaton methods and disentangle
their code, use a dynamically allocated buffer instead.
Discussion: https://www.postgresql.org/message-id/flat/c798fba5-8b71-4f27-c78e-37714037ea31%402ndquadrant.com
For historical reasons, the functions for peer authentication were
grouped under ident authentication. But they are really completely
separate, so give them their own section headings.
When cancelling REINDEX CONCURRENTLY after swapping the old and new
indexes (for example interruption at step 5), the old index remains
around and is marked as invalid. The old index should also be manually
droppable to clean up the parent relation from any invalid indexes still
remaining. For a partition index reindexed, pg_class.relispartition was
not getting updated, causing the index to not be droppable as DROP INDEX
would look for dependencies in a partition tree, which do not exist
anymore after the swap phase is done.
The fix here is simple: when swapping the old and new indexes, make sure
that pg_class.relispartition is correctly switched, similarly to what is
done for the index name.
Reported-by: Justin Pryzby
Author: Michael Paquier
Discussion: https://postgr.es/m/20191015164047.GA22729@telsasoft.com
Backpatch-through: 12
Teach get_expr_result_type() to manufacture a tuple descriptor directly
from a RowExpr node. If the RowExpr has type RECORD, this is the only
way to get a tupdesc for its result, since even if the rowtype has been
blessed, we don't have its typmod available at this point. (If the
RowExpr has some named composite type, we continue to let the existing
code handle it, since the RowExpr might well not have the correct column
names embedded in it.)
This fixes assorted corner cases illustrated by the added regression
tests.
Discussion: https://postgr.es/m/10872.1572202006@sss.pgh.pa.us
Commit 9556aa01c rearranged the innards of text_position() in a way
that would make it not work for empty search strings. Which is fine,
because all callers of that code special-case an empty pattern in
some way. However, the primary use-case (text_position itself) got
special-cased incorrectly: historically it's returned 1 not 0 for
an empty search string. Restore the historical behavior.
Per complaint from Austin Drenski (via Shay Rojansky).
Back-patch to v12 where it got broken.
Discussion: https://postgr.es/m/CADT4RqAz7oN4vkPir86Kg1_mQBmBxCp-L_=9vRpgSNPJf0KRkw@mail.gmail.com
When swapping the dependencies of the old and new indexes, the code has
been correctly switching all links in pg_depend from the old to the new
index for both referencing and referenced entries. However it forgot
the fact that the new index may itself have existing entries in
pg_depend, like references to the parent table attributes. This
resulted in duplicated entries in pg_depend after running REINDEX
CONCURRENTLY.
Fix this problem by removing any existing entries in pg_depend on the
new index before switching the dependencies of the old index to the new
one. More regression tests are added to check the consistency of
entries in pg_depend for indexes, including partition indexes.
Author: Michael Paquier
Discussion: https://postgr.es/m/20191025064318.GF8671@paquier.xyz
Backpatch-through: 12
9155580 has changed the value of the first fake LSN for unlogged
relations from 1 to FirstNormalUnloggedLSN (aka 1000), GiST requiring a
non-zero LSN on some pages to allow an interlocking logic to work, but
its value was still initialized to 1 at the beginning of recovery or
after running pg_resetwal. This fixes the initialization for both code
paths.
Author: Takayuki Tsunakawa
Reviewed-by: Dilip Kumar, Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/OSBPR01MB2503CE851940C17DE44AE3D9FE6F0@OSBPR01MB2503.jpnprd01.prod.outlook.com
Backpatch-through: 12
Remove SQL_LANGUAGES, which was eliminated in SQL:2008, and
SQL_PACKAGES and SQL_SIZING_PROFILES, which were eliminated in
SQL:2011. Since they were dropped by the SQL standard, the
information in them was no longer updated and therefore no longer
useful.
This also removes the feature-package association information in
sql_feature_packages.txt, but for the time begin we are keeping the
information which features are in the Core package (that is, mandatory
SQL features). Maybe at some point someone wants to invent a way to
store that that does not involve using the "package" mechanism
anymore.
Discussion https://www.postgresql.org/message-id/flat/91334220-7900-071b-9327-0c6ecd012017%402ndquadrant.com
Commit f8e5f156b added private state in postgres.c to track whether
a statement timeout is running. This seems like bad design to me;
timeout.c's private state should be the single source of truth about
that. We already fixed one bug associated with failure to keep those
states in sync (cf. be42015fc), and I've got little faith that we
won't find more in future. So get rid of postgres.c's local variable
by exposing a way to ask timeout.c whether a timeout is running.
(Obviously, such an inquiry is subject to race conditions, but it
seems fine for the purpose at hand.)
To make get_timeout_active() as cheap as possible, add a flag in
the per-timeout struct showing whether that timeout is active.
This allows some small savings elsewhere in timeout.c, mainly
elimination of unnecessary searches of the active_timeouts array.
While at it, fix enable_statement_timeout to not call disable_timeout
when statement_timeout is 0 and the timeout is not running. This
avoids a useless deschedule-and-reschedule-timeouts cycle, which
represents a significant savings (at least one kernel call) when
there is any other active timeout. Right now, there usually isn't,
but there are proposals around to change that.
Discussion: https://postgr.es/m/16035-456e6e69ebfd4374@postgresql.org
Historically, we started the timer (if StatementTimeout > 0) at the
beginning of a simple-Query message and usually let it run until the
end, so that the timeout limit applied to the entire query string,
and intra-string changes of the statement_timeout GUC had no effect.
But, confusingly, a COMMIT within the string would reset the state
and allow a fresh timeout cycle to start with the current setting.
Commit f8e5f156b changed the behavior of statement_timeout for extended
query protocol, and as an apparently-unintended side effect, a change in
the statement_timeout GUC during a multi-statement simple-Query message
might have an effect immediately --- but only if it was going from
"disabled" to "enabled".
This is all pretty confusing, not to mention completely undocumented.
Let's change things so that the timeout is always reset between queries
of a multi-query string, whether they're transaction control commands
or not. Thus the active timeout setting is applied to each query in
the string, separately. This costs a few more cycles if statement_timeout
is active, but it provides much more intuitive behavior, especially if one
changes statement_timeout in one of the queries of the string.
Also, add something to the documentation to explain all this.
Per bug #16035 from Raj Mohite. Although this is a bug fix, I'm hesitant
to back-patch it; conceivably somebody has worked out the old behavior
and is depending on it. (But note that this change should make the
behavior less restrictive in most cases, since the timeout will now
be applied to shorter segments of code.)
Discussion: https://postgr.es/m/16035-456e6e69ebfd4374@postgresql.org
Phases 2 (building the new index) and 3 (validating the new index)
checked for interrupts outside a transaction context, having as
consequence to not release session-level locks taken on the parent
relation and the old and new indexes processed. This could for example
be triggered with statement_timeout and a bad timing, and would issue
confusing error messages when shutting down the session still holding
the locks (note that an assertion failure would be triggered first), on
top of more issues with concurrent sessions trying to take a lock that
would interfere with the SHARE UPDATE EXCLUSIVE locks hold here.
This moves all the interruption checks inside a transaction context.
Note that I have manually tested all interruptions to make sure that
invalid indexes can be cleaned up properly. Partition indexes still
have issues on their own with some missing dependency handling, which
will be dealt with in a follow-up patch.
Reported-by: Justin Pryzby
Author: Michael Paquier
Discussion: https://postgr.es/m/20191013025145.GC4475@telsasoft.com
Backpatch-through: 12
In the first transaction run for REINDEX CONCURRENTLY, a thinko in the
existing logic caused two session locks to be taken on the old index,
causing the session lock on the newly-created index to be missed. This
made possible concurrent DDL commands (like ALTER INDEX) on the new
index while REINDEX CONCURRENTLY was processing from the point where the
first internal transaction committed.
This issue has been discovered while digging into another bug.
Author: Michael Paquier
Discussion: https://postgr.es/m/20191021074323.GB1869@paquier.xyz
Backpatch-through: 12
Any callback set would have no meaning in the context of an exception.
As an autovacuum worker exits quickly in this context, this could be
only an issue within EmitErrorReport(), where the elog hook is for
example called. That's unlikely to going to be a problem, but let's be
clean and consistent with other code paths handling exceptions. This is
present since 2909419, which introduced autovacuum.
Author: Ashwin Agrawal
Reviewed-by: Tom Lane, Michael Paquier
Discussion: https://postgr.es/m/CALfoeisM+_+dgmAdAOHAu0k-ZpEHHqSSG=GRf3pKJGm8OqWX0w@mail.gmail.com
Backpatch-through: 9.4
While casting from timestamp to timestamptz we do timestamp2tm() then
tm2timestamp(). This commit eliminates call to tm2timestamp(). Instead, it
directly applies timezone offset to the original timestamp value. That makes
upcoming datetime overflow handling in jsonpath easier. That should also save
us some CPU cycles.
Discussion: https://postgr.es/m/CAPpHfdvRPRh_mTGar5WmDeRZ%3DU5dOXHdxspYYD%3D76m3knNGjXA%40mail.gmail.com
Author: Alexander Korotkov
Reviewed-by: Tom Lane
We memorize all internal and empty leaf pages in the 1st vacuum stage for
gist indexes. They are used in the 2nd stage, to delete all the empty
pages. There was a memory context page_set_context for this purpose, but
we never used it.
Reported-by: Amit Kapila
Author: Dilip Kumar
Reviewed-by: Amit Kapila
Backpatch-through: 12, where it got introduced
Discussion: https://postgr.es/m/CAA4eK1LGr+MN0xHZpJ2dfS8QNQ1a_aROKowZB+MPNep8FVtwAA@mail.gmail.com
Since pluggable storage has been introduced, those two routines have
been replaced by table_open/close, with some compatibility macros still
present to allow extensions to compile correctly with v12.
Some code paths using the old routines still remained, so replace them.
Based on the discussion done, the consensus reached is that it is better
to remove those compatibility macros so as nothing new uses the old
routines, so remove also the compatibility macros.
Discussion: https://postgr.es/m/20191017014706.GF5605@paquier.xyz
recovery_min_apply_delay parameter is intended for use with streaming
replication deployments. However, the document clearly explains that
the parameter will be honored in all cases if it's specified. So it should
take effect even if in archive recovery. But, previously, archive recovery
with recovery_min_apply_delay enabled always failed, and caused assertion
failure if --enable-caasert is enabled.
The cause of this problem is that; the ownership of recoveryWakeupLatch
that recovery_min_apply_delay uses was taken only when standby mode
is requested. So unowned latch could be used in archive recovery, and
which caused the failure.
This commit changes recovery code so that the ownership of
recoveryWakeupLatch is taken even in archive recovery. Which prevents
archive recovery with recovery_min_apply_delay from failing.
Back-patch to v9.4 where recovery_min_apply_delay was added.
Author: Fujii Masao
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/CAHGQGwEyD6HdZLfdWc+95g=VQFPR4zQL4n+yHxQgGEGjaSVheQ@mail.gmail.com
In v11 or before, this setting could not take effect in crash recovery
because it's specified in recovery.conf and crash recovery always
starts without recovery.conf. But commit 2dedf4d9a8 integrated
recovery.conf into postgresql.conf and which unexpectedly allowed
this setting to take effect even in crash recovery. This is definitely
not good behavior.
To fix the issue, this commit makes crash recovery always ignore
recovery_min_apply_delay setting.
Back-patch to v12 where the issue was added.
Author: Fujii Masao
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/CAHGQGwEyD6HdZLfdWc+95g=VQFPR4zQL4n+yHxQgGEGjaSVheQ@mail.gmail.com
Discussion: https://postgr.es/m/e445616d-023e-a268-8aa1-67b8b335340c@pgmasters.net
Apparently while this code was being developed,
ReindexRelationConcurrently operated on multiple relations. The version
that was ultimately pushed doesn't, so this comment's use of plural is
inaccurate.
The timestamp tracking the last moment a message is received in a
logical replication worker was initialized in each loop checking if a
message was received or not, causing wal_receiver_timeout to be ignored
in basically any logical replication deployments. This also broke the
ping sent to the server when reaching half of wal_receiver_timeout.
This simply moves the initialization of the timestamp out of the apply
loop to the beginning of LogicalRepApplyLoop().
Reported-by: Jehan-Guillaume De Rorthais
Author: Julien Rouhaud
Discussion: https://postgr.es/m/CAOBaU_ZHESFcWva8jLjtZdCLspMj7vqaB2k++rjHLY897ZxbYw@mail.gmail.com
Backpatch-through: 10
Logical walsender should exit when it catches up with sending WAL during
shutdown; but there was a rare corner case when it failed to because of
a race condition that puts it back to wait for more WAL instead -- but
since there wasn't any, it'd not shut down immediately. It would only
continue the shutdown when wal_sender_timeout terminates the sleep,
which causes annoying waits during shutdown procedure. Restructure the
code so that we no longer forget to set WalSndCaughtUp in that case.
This was an oversight in commit c6c333436.
Backpatch all the way down to 9.4.
Author: Craig Ringer, Álvaro Herrera
Discussion: https://postgr.es/m/CAMsr+YEuz4XwZX_QmnX_-2530XhyAmnK=zCmicEnq1vLr0aZ-g@mail.gmail.com
Otherwise it can be hard to see where an error is coming from, when
the parallel worker sets all the GUCs that it received from the
leader. Bug #15726. Back-patch to 9.5, where RestoreGUCState()
appeared.
Reported-by: Tiago Anastacio
Reviewed-by: Daniel Gustafsson, Tom Lane
Discussion: https://postgr.es/m/15726-6d67e4fa14f027b3%40postgresql.org
Commits 801c2dc7 and 801c2dc7 made it possible for vacuum to
try to freeze a multixact that is still running. That was
prevented by a check, but raised an error. Repair.
Back-patch all the way.
Author: Nathan Bossart, Jeremy Schneider
Reported-by: Jeremy Schneider
Reviewed-by: Jim Nasby, Thomas Munro
Discussion: https://postgr.es/m/DAFB8AFF-2F05-4E33-AD7F-FF8B0F760C17%40amazon.com
A race condition can make us try to dereference a NULL pointer to the
PGPROC struct of a process that's already finished. That results in
crashes during REINDEX CONCURRENTLY and CREATE INDEX CONCURRENTLY.
This was introduced in ab0dfc961b, so backpatch to pg12.
Reported by: Justin Pryzby
Reviewed-by: Michaël Paquier
Discussion: https://postgr.es/m/20191012004446.GT10470@telsasoft.com
Using glibc's version string to detect potential collation definition
changes is not 100% reliable, but it's better than nothing. Currently
this affects only collations explicitly provided by "libc". More work
will be needed to handle the default collation.
Author: Thomas Munro, based on a suggestion from Christoph Berg
Reviewed-by: Peter Eisentraut
Discussion: https://postgr.es/m/4b76c6d4-ae5e-0dc6-7d0d-b5c796a07e34%402ndquadrant.com
Since the introduction of different slot types, in 1a0586de36, we
create a virtual slot in tuplesort_begin_cluster(). While that looks
right, it unfortunately doesn't actually work, as ExecStoreHeapTuple()
is used to store tuples in the slot. Unfortunately no regression tests
for CLUSTER on expression indexes existed so far.
Fix the slot type, and add bare bones tests for CLUSTER on expression
indexes.
Reported-By: Justin Pryzby
Author: Andres Freund
Discussion: https://postgr.es/m/20191011210320.GS10470@telsasoft.com
Backpatch: 12, like 1a0586de36
POSIX sigaction(2) can be told to block a set of signals while a
signal handler executes. Make use of that instead of manually
blocking and unblocking signals in the postmaster's signal handlers.
This should save a few cycles, and it also prevents recursive
invocation of signal handlers when many signals arrive in close
succession. We have seen buildfarm failures that seem to be due to
postmaster stack overflow caused by such recursion (exacerbated by
a Linux PPC64 kernel bug).
This doesn't change anything about the way that it works on Windows.
Somebody might consider adjusting port/win32/signal.c to let it work
similarly, but I'm not in a position to do that.
For the moment, just apply to HEAD. Possibly we should consider
back-patching this, but it'd be good to let it age awhile first.
Discussion: https://postgr.es/m/14878.1570820201@sss.pgh.pa.us
When dropping a column on a partitioned table which has one or more
partitioned indexes, the operation was failing as dependencies with
partitioned indexes using the column dropped were not getting removed in
a way consistent with the columns involved across all the relations part
of an inheritance tree.
This commit refactors the code executing column drop so as all the
columns from an inheritance tree to remove are gathered first, and
dropped all at the end. This way, we let the dependency machinery sort
out by itself the deletion of all the columns with the partitioned
indexes across a partition tree.
This issue has been introduced by 1d92a0c, so backpatch down to
REL_12_STABLE.
Author: Amit Langote, Michael Paquier
Reviewed-by: Álvaro Herrera, Ashutosh Sharma
Discussion: https://postgr.es/m/CA+HiwqE9kuBsZ3b5pob2-cvE8ofzPWs-og+g8bKKGnu6b4-yTQ@mail.gmail.com
Backpatch-through: 12
Within the context of SCRAM, "verifier" has a specific meaning in the
protocol, per RFCs. The existing code used "verifier" differently, to
mean whatever is or would be stored in pg_auth.rolpassword.
Fix this by using the term "secret" for this, following RFC 5803.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/be397b06-6e4b-ba71-c7fb-54cae84a7e18%402ndquadrant.com
In v11 or before, those settings could not take effect in crash recovery
because they are specified in recovery.conf and crash recovery always
starts without recovery.conf. But commit 2dedf4d9a8 integrated
recovery.conf into postgresql.conf and which unexpectedly allowed
those settings to take effect even in crash recovery. This is definitely
not good behavior.
To fix the issue, this commit makes crash recovery always ignore
restore_command and recovery_end_command settings.
Back-patch to v12 where the issue was added.
Author: Fujii Masao
Reviewed-by: Peter Eisentraut
Discussion: https://postgr.es/m/e445616d-023e-a268-8aa1-67b8b335340c@pgmasters.net
In c2fe139c20 I made ATRewriteTable() use tuple slots. Unfortunately
I did not notice that columns can be added in a rewrite that do not
have a default, when another column is added/altered requiring one.
Initialize columns to NULL again, and add tests.
Bug: #16038
Reported-By: anonymous
Author: Andres Freund
Discussion: https://postgr.es/m/16038-5c974541f2bf6749@postgresql.org
Backpatch: 12, where the bug was introduced in c2fe139c20
The file descriptor was opened with read-only to fsync a regular file,
which would cause EBADFD errors on some platforms.
This is similar to the recent fix done by a586cc4b (which was broken by
me with 82a5649), except that I noticed this issue while monitoring the
backend code for similar mistakes. Backpatch to 9.4, as this has been
introduced since logical decoding exists as of b89e151.
Author: Michael Paquier
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/20191006045548.GA14532@paquier.xyz
Backpatch-through: 9.4
As of d9dd406fe2, we require MSVC 2013,
which means _MSC_VER >= 1800. This means that conditionals about
older versions of _MSC_VER can be removed or simplified.
Previous code was also in some cases handling MinGW, where _MSC_VER is
not defined at all, incorrectly, such as in pg_ctl.c and win32_port.h,
leading to some compiler warnings. This should now be handled better.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
The postmaster's code path for spawning a bgworker neglected to check
whether we already have the max number of live child processes. That's
a bit hard to hit, since it would necessarily be a transient condition;
but if we do, AssignPostmasterChildSlot() fails causing a postmaster
crash, as seen in a report from Bhargav Kamineni.
To fix, invoke canAcceptConnections() in the bgworker code path, as we
do in the other code paths that spawn children. Since we don't want
the same pmState tests in this case, add a child-process-type parameter
to canAcceptConnections() so that it can know what to do.
Back-patch to 9.5. In principle the same hazard exists in 9.4, but the
code is enough different that this patch wouldn't quite fix it there.
Given the tiny usage of bgworkers in that branch it doesn't seem worth
creating a variant patch for it.
Discussion: https://postgr.es/m/18733.1570382257@sss.pgh.pa.us
Commit 1cff1b95a included some code that supposed it could repalloc()
a memory chunk to a smaller size without risk of the chunk moving.
That was not a great idea, because it depended on undocumented behavior
of AllocSetRealloc, which commit c477f3e44 changed thereby breaking it.
(Not to mention that this code ought to work with other memory context
types, which might not work the same...) So get rid of the repalloc
calls, and instead just wipe the now-unused ListCell array and/or tell
Valgrind it's NOACCESS, as if we'd freed it.
In cases where the initial list allocation had been quite large, this
could represent an annoying waste of space. In principle we could
ameliorate that by allocating the initial cell array separately when
it exceeds some threshold. But that would complicate new_list() which
is hot code, and the returns would materialize only in narrow cases.
On balance I don't think it'd be worth it.
Discussion: https://postgr.es/m/17059.1570208426@sss.pgh.pa.us
When ExecBRUpdateTriggers()'s GetTupleForTrigger() follows an EPQ
chain the former needs to run the result tuple through the junkfilter
again, and update the slot containing the new version of the tuple to
contain that new version. The input tuple may already be in the
junkfilter's output slot, which used to be OK - we don't need the
previous version anymore. Unfortunately ff11e7f4b9 started to use
ExecCopySlot() to update newslot, and ExecCopySlot() doesn't support
copying a slot into itself, leading to a slot in a corrupt
state, which then can cause crashes or other symptoms.
Fix this by skipping the ExecCopySlot() when copying into itself.
While we could have easily made ExecCopySlot() handle that case, it
seems better to add an assert forbidding doing so instead. As the goal
of copying might be to make the contents of one slot independent from
another, it seems failure prone to handle doing so silently.
A follow-up commit will add tests for the obviously under-covered
combination of EPQ and triggers. Done as a separate commit as it might
make sense to backpatch them further than this bug.
Also remove confusion with confusing variable names for slots in
ExecBRDeleteTriggers() and ExecBRUpdateTriggers().
Bug: #16036
Reported-By: Антон Власов
Author: Andres Freund
Discussion: https://postgr.es/m/16036-28184c90d952fb7f@postgresql.org
Backpatch: 12-, where ff11e7f4b9 was merged
Cribbing from dfbaed45975:
Some operating systems, including the reporter's windows, return EBADFD
or similar when fsync() is invoked on a O_RDONLY file descriptor.
Unfortunately RestoreSlotFromDisk() does exactly that; which causes
failures after restarts in at least some scenarios.
If you hit the bug the error message will be something like
ERROR: could not fsync file "pg_replslot/$name/state": Bad file descriptor
Simply use O_RDWR instead of O_RDONLY when opening the relevant file
descriptor to fix the bug.
Unfortunately this fix was undone in 82a5649fb9. Re-apply, and add a
comment.
Bug: 16039
Reported-By: Hans Buschmann
Author: Andres Freund
Discussion: https://postgr.es/m/16039-196fc97cc05e141c@postgresql.org
Backpatch: 12-, as 82a5649fb9
The old names for the attribute-detoasting functions names included
the word "heap," which seems outdated now that the heap is only one of
potentially many table access methods.
On the other hand, toast_insert_or_update and toast_delete are
heap-specific, so rename them by adding "heap_" as a prefix.
Not all of the work of making the TOAST system fully accessible to AMs
other than the heap is done yet, but there seems to be little harm in
getting this renaming out of the way now. Commit
8b94dab066 already divided up the
functions among various files partially according to whether it was
intended that they should be heap-specific or AM-agnostic, so this is
just clarifying the division contemplated by that commit.
Patch by me, reviewed and tested by Prabhat Sabu, Thomas Munro,
Andres Freund, and Álvaro Herrera.
Discussion: http://postgr.es/m/CA+TgmoZv-=2iWM4jcw5ZhJeL18HF96+W1yJeYrnGMYdkFFnEpQ@mail.gmail.com
Commit 5ac0d9360 failed to entirely fix bitshiftright's habit of
leaving one-bits in the pad space that should be all zeroes,
because in a moment of sheer brain fade I'd concluded that only
the code path used for not-a-multiple-of-8 shift distances needed
to be fixed. Of course, a multiple-of-8 shift distance can also
cause the problem, so we need to forcibly zero the extra bits
in both cases.
Per bug #16037 from Alexander Lakhin. As before, back-patch to all
supported branches.
Discussion: https://postgr.es/m/16037-1d1ebca564db54f4@postgresql.org
Commit 5dd7fc1519 added block-level memory accounting, but used int64 variable to
track the amount of allocated memory. That is incorrect, because we have Size for
exactly these purposes, but it was mostly harmless until c477f3e449 which changed
how we handle with repalloc() when downsizing the chunk. Previously we've ignored
these cases and just kept using the original chunk, but now we need to update the
accounting, and the code was doing this:
context->mem_allocated += blksize - oldblksize;
Both blksize and oldblksize are Size (so unsigned) which means the subtraction
underflows, producing a very high positive value. On 64-bit platforms (where Size
has the same size as mem_alllocated) this happens to work because the result wraps
to the right value, but on (some) 32-bit platforms this fails.
This fixes two things - it changes mem_allocated (and related variables) to Size,
and it splits the update to two separate steps, to prevent any underflows.
Discussion: https://www.postgresql.org/message-id/15151.1570163761%40sss.pgh.pa.us
Encoding conversion uses the very simplistic rule that the output
can't be more than 4X longer than the input, and palloc's a buffer
of that size. This results in failure to convert any string longer
than 1/4 GB, which is becoming an annoying limitation.
As a band-aid to improve matters, allow the allocated output buffer
size to exceed 1GB. We still insist that the final result fit into
MaxAllocSize (1GB), though. Perhaps it'd be safe to relax that
restriction, but it'd require close analysis of all callers, which
is daunting (not least because external modules might call these
functions). For the moment, this should allow a 2X to 4X improvement
in the longest string we can convert, which is a useful gain in
return for quite a simple patch.
Also, once we have successfully converted a long string, repalloc
the output down to the actual string length, returning the excess
to the malloc pool. This seems worth doing since we can usually
expect to give back several MB if we take this path at all.
This still leaves much to be desired, most notably that the assumption
that MAX_CONVERSION_GROWTH == 4 is very fragile, and yet we have no
guard code verifying that the output buffer isn't overrun. Fixing
that would require significant changes in the encoding conversion
APIs, so it'll have to wait for some other day.
The present patch seems safely back-patchable, so patch all supported
branches.
Alvaro Herrera and Tom Lane
Discussion: https://postgr.es/m/20190816181418.GA898@alvherre.pgsql
Discussion: https://postgr.es/m/3614.1569359690@sss.pgh.pa.us
Up to now, if you resized a large (>8K) palloc chunk down to a smaller
size, aset.c made no attempt to return any space to the malloc pool.
That's unpleasant if a really large allocation is resized to a
significantly smaller size. I think no such cases existed when this
code was designed, and I'm not sure whether they're common even yet,
but an upcoming fix to encoding conversion will certainly create such
cases. Therefore, fix AllocSetRealloc so that it gives realloc()
a chance to do something with the block. This doesn't noticeably
increase complexity, we mostly just have to change the order in which
the cases are considered.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/20190816181418.GA898@alvherre.pgsql
Discussion: https://postgr.es/m/3614.1569359690@sss.pgh.pa.us
query_tree_walker and query_tree_mutator were skipping the
windowClause of the query, without regard for the fact that the
startOffset and endOffset in a WindowClause node are expression trees
that need to be processed. This was an oversight in commit ec4be2ee6
from 2010 which added the expression fields; the main symptom is that
function parameters in window frame clauses don't work in inlined
functions.
Fix (as conservatively as possible since this needs to not break
existing out-of-tree callers) and add tests.
Backpatch all the way, since this has been broken since 9.0.
Per report from Alastair McKinley; fix by me with kibitzing and review
from Tom Lane.
Discussion: https://postgr.es/m/DB6PR0202MB2904E7FDDA9D81504D1E8C68E3800@DB6PR0202MB2904.eurprd02.prod.outlook.com
cbc55da has reworked the order of some actions at the end of archive
recovery. Unfortunately this overlooked the fact that the startup
process needs to remove RECOVERYXLOG (for temporary WAL segment newly
recovered from archives) and RECOVERYHISTORY (for temporary history
file) at this step, leaving the files around even after recovery ended.
Backpatch to 9.5, like the previous commit.
Author: Sawada Masahiko
Reviewed-by: Fujii Masao, Michael Paquier
Discussion: https://postgr.es/m/CAD21AoBO_eDQub6zojFnWtnmutRBWvYf7=cW4Hsqj+U_R26w3Q@mail.gmail.com
Backpatch-through: 9.5
The location of the session end hook has been chosen so as it is
possible to allow modules to do their own transactions, however any
trying to any any subsystem which went through before_shmem_exit()
would cause issues, limiting the pluggability of the hook.
Per discussion with Tom Lane and Andres Freund.
Discussion: https://postgr.es/m/18722.1569906636@sss.pgh.pa.us
Commit 4d0e994eed added support for partial TOAST decompression, so the
decompression is interrupted after producing the requested prefix. For
prefix and slices near the beginning of the entry, this may saves a lot
of decompression work.
That however only deals with decompression - the whole compressed entry
was still fetched and re-assembled, even though the compression used
only a small fraction of it. This commit improves that by computing how
much compressed data may be needed to decompress the requested prefix,
and then fetches only the necessary part.
We always need to fetch a bit more compressed data than the requested
(uncompressed) prefix, because the prefix may not be compressible at all
and pglz itself adds a bit of overhead. That means this optimization is
most effective when the requested prefix is much smaller than the whole
compressed entry.
Author: Binguo Bao
Reviewed-by: Andrey Borodin, Tomas Vondra, Paul Ramsey
Discussion: https://www.postgresql.org/message-id/flat/CAL-OGkthU9Gs7TZchf5OWaL-Gsi=hXqufTxKv9qpNG73d5na_g@mail.gmail.com
These hooks can be used in loadable modules. A simple test module is
included.
The first attempt was done with cd8ce3a but we lacked handling for
NO_INSTALLCHECK in the MSVC scripts (problem solved afterwards by
431f1599) so the buildfarm got angry. This also fixes a couple of
issues noticed upon review compared to the first attempt, so the code
has slightly changed, resulting in a more simple test module.
Author: Fabrízio de Royes Mello, Yugo Nagata
Reviewed-by: Andrew Dunstan, Michael Paquier, Aleksandr Parfenov
Discussion: https://postgr.es/m/20170720204733.40f2b7eb.nagata@sraoss.co.jp
Discussion: https://postgr.es/m/20190823042602.GB5275@paquier.xyz
Adds accounting of memory allocated in a memory context. Compared to
various ad hoc solutions, the main advantage is that the accounting is
transparent and does not require direct control over allocations (this
matters for use cases where the allocations happen in user code, like
for example aggregate states allocated in a transition functions).
To reduce overhead, the accounting happens at the block level (not for
individual chunks) and only the context immediately owning the block is
updated. When inquiring about amount of memory allocated in a context,
we have to recursively walk all children contexts.
This "lazy" accounting works well for cases with relatively small number
of contexts in the relevant subtree and/or with infrequent inquiries.
Author: Jeff Davis
Reivewed-by: Tomas Vondra, Melanie Plageman, Soumyadeep Chakraborty
Discussion: https://www.postgresql.org/message-id/flat/027a129b8525601c6a680d27ce3a7172dab61aab.camel@j-davis.com
That avoids unnecessary work during both interpreted execution, and
JIT compiled expression evaluation. Both benefit from fewer expression
steps needing be processed, and for interpreted execution there now is
a fastpath dedicated to just fetching a value from a virtual
slot. That's e.g. beneficial for hashjoins over nodes that perform
projections, as the hashed columns are currently fetched individually.
Author: Soumyadeep Chakraborty, Andres Freund
Discussion: https://postgr.es/m/CAE-ML+9OKSN71+mHtfMD-L24oDp8dGTfaVjDU6U+j+FNAW5kRQ@mail.gmail.com
In v11 or before, recovery target settings could not take effect in
crash recovery because they are specified in recovery.conf and
crash recovery always starts without recovery.conf. But commit
2dedf4d9a8 integrated recovery.conf into postgresql.conf and
which unexpectedly allowed recovery target settings to take effect
even in crash recovery. This is definitely not good behavior.
To fix the issue, this commit makes crash recovery always ignore
recovery target settings.
Back-patch to v12.
Author: Peter Eisentraut
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/e445616d-023e-a268-8aa1-67b8b335340c@pgmasters.net
In the course of 5567d12ce0, 356687bd8 and 317ffdfeaa, I changed
BuildTupleHashTable[Ext]'s call to ExecBuildGroupingEqual to not pass
in the parent node, but NULL. Which in turn prevents the tuple
equality comparator from being JIT compiled. While that fixes
bug #15486, it is not actually necessary after all of the above commits,
as we don't re-build the comparator when using the new
BuildTupleHashTableExt() interface (as the content of the hashtable
are reset, but the TupleHashTable itself is not).
Therefore re-allow jit compilation for callers that use
BuildTupleHashTableExt with a separate context for "metadata" and
content.
As in the previous commit, there's ongoing work to make this easier to
test to prevent such regressions in the future, but that
infrastructure is not going to be backpatchable.
The performance impact of not JIT compiling hashtable equality
comparators can be substantial e.g. for aggregation queries that
aggregate a lot of input rows to few output rows (when there are a lot
of output groups, there will be fewer comparisons).
Author: Andres Freund
Discussion: https://postgr.es/m/20190927072053.njf6prdl3vb7y7qb@alap3.anarazel.de
Backpatch: 11, just as 5567d12ce0
For many queries the fact that the tuple descriptor from the lower
node was not taken into account when determining whether the type of a
slot is fixed, lead to tuple deforming for such upper nodes not to be
JIT accelerated.
I broke this in 675af5c01e.
There is ongoing work to enable writing regression tests for related
behavior (including a patch that would have detected this
regression), by optionally showing such details in EXPLAIN. But as it
seems unlikely that that will be suitable for stable branches, just
merge the fix for now.
While it's fairly close to the 12 release window, the fact that 11
continues to perform JITed tuple deforming in these cases, that
there's still cases where we do so in 12, and the fact that the
performance regression can be sizable, weigh in favor of fixing it
now.
Author: Andres Freund
Discussion: https://postgr.es/m/20190927072053.njf6prdl3vb7y7qb@alap3.anarazel.de
Backpatch: 12-, where 675af5c01e was merged.
Some older OpenSSL versions (0.9.8 branch) define TLS*_VERSION macros
but not the corresponding SSL_OP_NO_* macro, which causes the code for
handling ssl_min_protocol_version/ssl_max_protocol_version to fail to
compile. To fix, add more #ifdefs and error handling.
Reported-by: Victor Wagner <vitus@wagner.pp.ru>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/20190924101859.09383b4f%40fafnir.local.vm
HEAD supports OpenSSL 0.9.8 and newer versions, and this code likely got
forgotten as its surrounding comments mention an incorrect version
number.
Author: Michael Paquier
Reviewed-by: Peter Eisentraut
Discussion: https://postgr.es/m/20190927032311.GB8485@paquier.xyz
For some reason at least gcc-9 warns about the fallthrough, even
though it otherwise recognizes that elog(ERROR, ...) doesn't return.
Author: Andres Freund
The code was enforcing AccessExclusiveLock for all custom relation
options, which is incorrect as the APIs allow a custom lock level to be
set.
While on it, fix a couple of inconsistencies in the tests and the README
of dummy_index_am.
Oversights in commit 773df88.
Discussion: https://postgr.es/m/20190925234152.GA2115@paquier.xyz
LIKE INCLUDING DEFAULTS tried to copy the attrdef expression without
copying the state of the attgenerated column. This is in fact wrong,
because GENERATED and DEFAULT expressions are not the same kind of animal;
one can contain Vars and the other not. We *must* copy attgenerated
when we're copying the attrdef expression. Rearrange the if-tests
so that the expression is copied only when the correct one of
INCLUDING DEFAULTS and INCLUDING GENERATED has been specified.
Per private report from Manuel Rigger.
Tom Lane and Peter Eisentraut
This commit implements jsonpath .datetime() method as it's specified in
SQL/JSON standard. There are no-argument and single-argument versions of
this method. No-argument version selects first of ISO datetime formats
matching input string. Single-argument version accepts template string as
its argument.
Additionally to .datetime() method itself this commit also implements
comparison ability of resulting date and time values. There is some difficulty
because exising jsonb_path_*() functions are immutable, while comparison of
timezoned and non-timezoned types involves current timezone. At first, current
timezone could be changes in session. Moreover, timezones themselves are not
immutable and could be updated. This is why we let existing immutable functions
throw errors on such non-immutable comparison. In the same time this commit
provides jsonb_path_*_tz() functions which are stable and support operations
involving timezones. As new functions are added to the system catalog,
catversion is bumped.
Support of .datetime() method was the only blocker prevents T832 from being
marked as supported. sql_features.txt is updated correspondingly.
Extracted from original patch by Nikita Glukhov, Teodor Sigaev, Oleg Bartunov.
Heavily revised by me. Comments were adjusted by Liudmila Mantrova.
Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Alexander Korotkov, Nikita Glukhov, Teodor Sigaev, Oleg Bartunov, Liudmila Mantrova
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut
SQL/JSON standard allows manipulation with datetime values. So, it appears to
be convinient to allow datetime values to be represented in JsonbValue struct.
These datetime values are allowed for temporary representation only. During
serialization datetime values are converted into strings.
SQL/JSON requires writing timestamps with timezone in the same timezone offset
as they were parsed. This is why we allow storage of timezone offset in
JsonbValue struct. For the same reason timezone offset argument is added to
JsonEncodeDateTime() function.
Extracted from original patch by Nikita Glukhov, Teodor Sigaev, Oleg Bartunov.
Revised by me. Comments were adjusted by Liudmila Mantrova.
Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Nikita Glukhov, Teodor Sigaev, Oleg Bartunov, Alexander Korotkov, Liudmila Mantrova
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut
Add support of error suppression in some date and time manipulation functions
as it's required for jsonpath .datetime() method support. This commit doesn't
use PG_TRY()/PG_CATCH() in order to implement that. Instead, it provides
internal versions of date and time functions used, which support error
suppression.
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Alexander Korotkov, Nikita Glukhov
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut
This commit adds parse_datetime() function, which implements datetime
parsing with extended features demanded by upcoming jsonpath .datetime()
method:
* Dynamic type identification based on template string,
* Support for standard-conforming 'strict' mode,
* Timezone offset is returned as separate value.
Extracted from original patch by Nikita Glukhov, Teodor Sigaev, Oleg Bartunov.
Revised by me.
Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Nikita Glukhov, Teodor Sigaev, Oleg Bartunov, Alexander Korotkov
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut
SQL Standard 2016 defines rules for handling separators in datetime template
strings, which are different to to_date()/to_timestamp() rules. Standard
allows only small set of separators and requires strict matching for them.
Standard applies to jsonpath .datetime() method and CAST (... FORMAT ...) SQL
clause. We're not going to change handling of separators in existing
to_date()/to_timestamp() functions, because their current behavior is familiar
for users. Standard behavior now available by special flag, which will be used
in upcoming .datetime() jsonpath method.
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Alexander Korotkov
All our current in core relation options of type string (not many,
admittedly) behave in reality like enums. But after seeing an
implementation for enum reloptions, it's clear that strings are messier,
so introduce the new reloption type. Switch all string options to be
enums instead.
Fortunately we have a recently introduced test module for reloptions, so
we don't lose coverage of string reloptions, which may still be used by
third-party modules.
Authors: Nikolay Shaplov, Álvaro Herrera
Reviewed-by: Nikita Glukhov, Aleksandr Parfenov
Discussion: https://postgr.es/m/43332102.S2V5pIjXRx@x200m
Relation options can define a lock mode other than AccessExclusiveMode
since 47167b7, but modules defining custom relation options did not
really have a way to enforce that. Correct that by extending the
current API set so as modules can define a custom lock mode.
Author: Michael Paquier
Reviewed-by: Kuntal Ghosh
Discussion: https://postgr.es/m/20190920013831.GD1844@paquier.xyz
In-core relation options can use a custom lock mode since 47167b7, that
has lowered the lock available for some autovacuum parameters. However
it forgot to consider custom relation options. This causes failures
with ALTER TABLE SET when changing a custom relation option, as its lock
is not defined. The existing APIs to define a custom reloption does not
allow to define a custom lock mode, so enforce its initialization to
AccessExclusiveMode which should be safe enough in all cases. An
upcoming patch will extend the existing APIs to allow a custom lock mode
to be defined.
The problem can be reproduced with bloom indexes, so add a test there.
Reported-by: Nikolay Sharplov
Analyzed-by: Thomas Munro, Michael Paquier
Author: Michael Paquier
Reviewed-by: Kuntal Ghosh
Discussion: https://postgr.es/m/20190920013831.GD1844@paquier.xyz
Backpatch-through: 9.6
The state-tracking of WAL reading in various places was pretty messy,
mostly because the ancient physical-replication WAL reading code wasn't
using the XLogReader abstraction. This led to some untidy code. Make
it prettier by creating two additional supporting structs,
WALSegmentContext and WALOpenSegment which keep track of WAL-reading
state. This makes code cleaner, as well as supports more future
cleanup.
Author: Antonin Houska
Reviewed-by: Álvaro Herrera and (older versions) Robert Haas
Discussion: https://postgr.es/m/14984.1554998742@spoje.net
Fix an oversight in commit 7266d0997: as it stood, the code failed
when a function-in-FROM returns composite and can be simplified
to a composite constant.
For the moment, just test for composite result and abandon pullup
if we see one. To make it actually work, we'd have to decompose
the composite constant into per-column constants; which is surely
do-able, but I'm not convinced it's worth the code space.
Per report from Raúl Marín Rodríguez.
Discussion: https://postgr.es/m/CAM6_UM4isP+buRA5sWodO_MUEgutms-KDfnkwGmryc5DGj9XuQ@mail.gmail.com
When a relation is truncated, shared_buffers needs to be scanned
so that any buffers for the relation forks are invalidated in it.
Previously, shared_buffers was scanned for each relation forks, i.e.,
MAIN, FSM and VM, when VACUUM truncated off any empty pages
at the end of relation or TRUNCATE truncated the relation in place.
Since shared_buffers needed to be scanned multiple times,
it could take a long time to finish those commands especially
when shared_buffers was large.
This commit changes the logic so that shared_buffers is scanned only
one time for those three relation forks.
Author: Kirk Jamison
Reviewed-by: Masahiko Sawada, Thomas Munro, Alvaro Herrera, Takayuki Tsunakawa and Fujii Masao
Discussion: https://postgr.es/m/D09B13F772D2274BB348A310EE3027C64E2067@g01jpexmbkw24
If the bitstring length is not a multiple of 8, we'd shift the
rightmost bits into the pad space, which must be zeroes --- bit_cmp,
for one, depends on that. This'd lead to the result failing to
compare equal to what it should compare equal to, as reported in
bug #16013 from Daryl Waycott.
This is, if memory serves, not the first such bug in the bitstring
functions. In hopes of making it the last one, do a bit more work
than minimally necessary to fix the bug:
* Add assertion checks to bit_out() and varbit_out() to complain if
they are given incorrectly-padded input. This will improve the
odds that manual testing of any new patch finds problems.
* Encapsulate the padding-related logic in macros to make it
easier to use.
Also, remove unnecessary padding logic from bit_or() and bitxor().
Somebody had already noted that we need not re-pad the result of
bit_and() since the inputs are required to be the same length,
but failed to extrapolate that to the other two.
Also, move a comment block that once was near the head of varbit.c
(but people kept putting other stuff in front of it), to put it in
the header block.
Note for the release notes: if anyone has inconsistent data as a
result of saving the output of bitshiftright() in a table, it's
possible to fix it with something like
UPDATE mytab SET bitcol = ~(~bitcol) WHERE bitcol != ~(~bitcol);
This has been broken since day one, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/16013-c2765b6996aacae9@postgresql.org
The code used the destination slot's natts where it intended to
use the source slot's natts. Adding an Assert shows that there
is no case in "make check-world" where these counts are different,
so maybe this is a harmless bug, but it's still a bug.
Takayuki Tsunakawa
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1FD34C0E@G01JPEXMBYT05
Move the responsibility for advancing the NOTIFY queue tail pointer
from the listener(s) to the notification sender, and only have the
sender do it once every few queue pages, rather than after every batch
of notifications as at present. This reduces the number of times we
execute asyncQueueAdvanceTail, and reduces contention when there are
multiple listeners (since that function requires exclusive lock).
This change relies on the observation that we don't really need the tail
pointer to be exactly up-to-date. It's certainly not necessary to
attempt to release disk space more often than once per SLRU segment.
The only other usage of the tail pointer is that an incoming listener,
if it's the only listener in its database, will need to scan the queue
forward from the tail; but that's surely a less performance-critical
path than routine sending and receiving of notifies. We compromise by
advancing the tail pointer after every 4 pages of output, so that it
shouldn't get more than a few pages behind.
Also, when sending signals to other backends after adding notify
message(s) to the queue, recognize that only backends in our own
database are going to care about those messages, so only such
backends really need to be awakened promptly. Backends in other
databases should get kicked if they're well behind on reading the
queue, else they'll hold back the global tail pointer; but wakening
them for every single message is pointless. This change can
substantially reduce signal traffic if listeners are spread among
many databases. It won't help for the common case of only a single
active database, but the extra check costs very little.
Martijn van Oosterhout, with some adjustments by me
Discussion: https://postgr.es/m/CADWG95vtRBFDdrx1JdT1_9nhOFw48KaeTev6F_LtDQAFVpSPhA@mail.gmail.com
Discussion: https://postgr.es/m/CADWG95uFj8rLM52Er80JnhRsTbb_AqPP1ANHS8XQRGbqLrU+jA@mail.gmail.com
Since we introduced the idea of leakproof functions, texteq and textne
were marked leakproof but their sibling text comparison functions were
not. This inconsistency seemed justified because texteq/textne just
relied on memcmp() and so could easily be seen to be leakproof, while
the other comparison functions are far more complex and indeed can
throw input-dependent errors.
However, that argument crashed and burned with the addition of
nondeterministic collations, because now texteq/textne may invoke
the exact same varstr_cmp() infrastructure as the rest. It makes no
sense whatever to give them different leakproofness markings.
After a certain amount of angst we've concluded that it's all right
to consider varstr_cmp() to be leakproof, mostly because the other
choice would be disastrous for performance of many queries where
leakproofness matters. The input-dependent errors should only be
reachable for corrupt input data, or so we hope anyway; certainly,
if they are reachable in practice, we've got problems with requirements
as basic as maintaining a btree index on a text column.
Hence, run around to all the SQL functions that derive from varstr_cmp()
and mark them leakproof. This should result in a useful gain in
flexibility/performance for queries in which non-leakproofness degrades
the efficiency of the query plan.
Back-patch to v12 where nondeterministic collations were added.
While this isn't an essential bug fix given the determination
that varstr_cmp() is leakproof, we might as well apply it now that
we've been forced into a post-beta4 catversion bump.
Discussion: https://postgr.es/m/31481.1568303470@sss.pgh.pa.us
text_pattern_ops and its siblings can't be used with nondeterministic
collations, because they use the text_eq operator which will not behave
as bitwise equality if applied with a nondeterministic collation. The
initial implementation of that restriction was to insert a run-time test
in the related comparison functions, but that is inefficient, may throw
misleading errors, and will throw errors in some cases that would work.
It seems sufficient to just prevent the combination during CREATE INDEX,
so do that instead.
Lacking any better way to identify the opclasses involved, we need to
hard-wire tests for them, which requires hand-assigned values for their
OIDs, which forces a catversion bump because they previously had OIDs
that would be assigned automatically. That's slightly annoying in the
v12 branch, but fortunately we're not at rc1 yet, so just do it.
Back-patch to v12 where nondeterministic collations were added.
In passing, run make reformat-dat-files, which found some unrelated
whitespace issues (slightly different ones in HEAD and v12).
Peter Eisentraut, with small corrections by me
Discussion: https://postgr.es/m/22566.1568675619@sss.pgh.pa.us
The new function stashes its output value in a JsonbValue that can be
passed in by the caller, which enables some of them to pass
stack-allocated structs -- saving palloc cycles. It also allows some
callers that know they are handling a jsonb object to use this new jsonb
object-specific API, instead of going through generic container
findJsonbValueFromContainer.
Author: Nikita Glukhov
Discussion: https://postgr.es/m/7c417f90-f95f-247e-ba63-d95e39c0ad14@postgrespro.ru
Instead of creating an iterator object at each step down the JSONB
object/array, we can just just examine its object/array flags, which is
faster. Also, use the recently introduced JsonbValueAsText instead of
open-coding the same thing, for code simplicity.
Author: Nikita Glukhov
Discussion: https://postgr.es/m/7c417f90-f95f-247e-ba63-d95e39c0ad14@postgrespro.ru
jsonb_object_field_text and jsonb_array_element_text both contained
identical copies of this code, so extract that into new routine
JsonbValueAsText. This can also be used in other places, to measurable
performance benefit: the jsonb_each() and jsonb_array_elements()
functions can use it for outputting text forms instead of their less
efficient current implementation (because we no longer need to build
intermediate a jsonb representation of each value).
Author: Nikita Glukhov
Discussion: https://postgr.es/m/7c417f90-f95f-247e-ba63-d95e39c0ad14@postgrespro.ru
Although the SQL/JSON tech report makes reference to ECMAScript which
allows both single- and double-quoted strings, all the rest of the
report speaks only of double-quoted string literals in jsonpaths.
That's more compatible with JSON itself; moreover single-quoted strings
are hard to use inside a jsonpath that is itself a single-quoted SQL
literal. So guess that the intent is to allow only double-quoted
literals, and remove lexer support for single-quoted literals.
It'll be less painful to add this again later if we're wrong, than to
remove a shipped feature.
Also, adjust the lexer so that unrecognized backslash sequences are
treated as just meaning the escaped character, not as errors. This
change has much better support in the standards, as JSON, JavaScript
and ECMAScript all make it plain that that's what's supposed to
happen.
Back-patch to v12.
Discussion: https://postgr.es/m/CAPpHfdvDci4iqNF9fhRkTqhe-5_8HmzeLt56drH%2B_Rv2rNRqfg@mail.gmail.com
This commit improves subject in two ways:
* It removes ugliness of 02f90879e7, which stores distance values and null
flags in two separate arrays after GISTSearchItem struct. Instead we pack
both distance value and null flag in IndexOrderByDistance struct. Alignment
overhead should be negligible, because we typically deal with at most few
"col op const" expressions in ORDER BY clause.
* It fixes handling of "col op NULL" expression in KNN-SP-GiST. Now, these
expression are not passed to support functions, which can't deal with them.
Instead, NULL result is implicitly assumed. It future we may decide to
teach support functions to deal with NULL arguments, but current solution is
bugfix suitable for backpatch.
Reported-by: Nikita Glukhov
Discussion: https://postgr.es/m/826f57ee-afc7-8977-c44c-6111d18b02ec%40postgrespro.ru
Author: Nikita Glukhov
Reviewed-by: Alexander Korotkov
Backpatch-through: 9.4
Make the error messages around GSSAPI encryption a bit clearer. Tweak
some messages to avoid plural problems.
Also make a code change for clarity. Using "conf" for "confidential"
is quite confusing. Using "conf_state" is perhaps not much better but
that's what the GSSAPI documentation uses, so there is at least some
hope of understanding it.
The SQL spec defers to XQuery to define what the option flags are
for LIKE_REGEX patterns. XQuery says that:
* 's' allows the dot character to match newlines, which by
default it will not;
* 'm' allows ^ and $ to match at newlines, not only at the
start/end of the whole string.
Thus, these are *not* inverses as they are for the similarly-named
POSIX options, and neither one corresponds to the POSIX 'n' option.
Fortunately, Spencer's library does expose these two behaviors as
separately twiddlable flags, so we just have to fix the mapping from
JSP flag bits to REG flag bits. I also chose to rename the symbol
for 's' to DOTALL, to make it clearer that it's not the inverse
of MLINE.
Also, XQuery says that if the 'q' flag "is used together with the m, s,
or x flag, that flag has no effect". I read this as saying that 'q'
overrides the other flags; whoever wrote our code seems to have read
it backwards.
Lastly, while XQuery's 'x' flag is related to what Spencer's code
does for REG_EXPANDED, it's not the same or a subset. It seems best
to treat XQuery's 'x' as unimplemented for now. Maybe later we can
expand our regex code to offer 'x'-style parsing as a separate option.
While at it, refactor the jsonpath code so that (a) there's only
one copy of the flag transformation logic not two, and (b) the
processing of flags is independent of the order in which the flags
are written.
We need some documentation updates to go with this, but I'll
tackle that separately.
Back-patch to v12 where this code originated.
Discussion: https://postgr.es/m/CAPpHfdvDci4iqNF9fhRkTqhe-5_8HmzeLt56drH%2B_Rv2rNRqfg@mail.gmail.com
Reference: https://www.w3.org/TR/2017/REC-xpath-functions-31-20170321/#flags
SQL Standard 2016 defines SSSSS format pattern for seconds past midnight in
jsonpath .datetime() method and CAST (... FORMAT ...) SQL clause. In our
datetime parsing engine we currently support it with SSSS name.
This commit adds SSSSS as an alias for SSSS. Alias is added in favor of
upcoming jsonpath .datetime() method. But it's also supported in to_date()/
to_timestamp() as positive side effect.
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Nikita Glukhov, Alexander Korotkov
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut
SQL Standard 2016 defines FF1-FF9 format patters for fractions of seconds in
jsonpath .datetime() method and CAST (... FORMAT ...) SQL clause. Parsing
engine of upcoming .datetime() method will be shared with to_date()/
to_timestamp().
This patch implements FF1-FF6 format patterns for upcoming jsonpath .datetime()
method. to_date()/to_timestamp() functions will also get support of this
format patterns as positive side effect. FF7-FF9 are not supported due to
lack of precision in our internal timestamp representation.
Extracted from original patch by Nikita Glukhov, Teodor Sigaev, Oleg Bartunov.
Heavily revised by me.
Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Nikita Glukhov, Teodor Sigaev, Oleg Bartunov, Alexander Korotkov
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut
Most WAL records are ignored in early SnapBuild snapshot build phases.
But it's critical to process some of them, so that later messages have
the correct transaction state after the snapshot is completely built; in
particular, XLOG_XACT_ASSIGNMENT messages are critical in order for
sub-transactions to be correctly assigned to their parent transactions,
or at least one assert misbehaves, as reported by Ildar Musin.
Diagnosed-by: Masahiko Sawada
Author: Masahiko Sawada
Discussion: https://postgr.es/m/CAONYFtOv+Er1p3WAuwUsy1zsCFrSYvpHLhapC_fMD-zNaRWxYg@mail.gmail.com
The progress state was being clobbered once the first index completed
being rebuilt, causing the final phases of the operation not show
anything in the progress view. This was inadvertently broken in
03f9e5cba0, which added progress tracking for REINDEX.
(The reason this bugfix is this small is that I had already noticed this
problem when writing monitoring for CREATE INDEX, and had already worked
around it, as can be seen in discussion starting at
https://postgr.es/m/20190329150218.GA25010@alvherre.pgsql Fixing the
problem is just a matter of fixing one place touched by the REINDEX
monitoring.)
Reported by: Álvaro Herrera
Author: Álvaro Herrera
Discussion: https://postgr.es/m/20190801184333.GA21369@alvherre.pgsql
Include newitemoff in rmgr desc output for nbtree page split records.
In passing, correct an obsolete comment that claimed that newitemoff is
only logged for _L variant nbtree page split WAL records.
Both issues were oversights in commit 2c03216d83, which revamped the
WAL format.
Author: Peter Geoghegan
Backpatch: 9.5-, where the WAL format was revamped.
This is a second try at what commit 57431a911 tried to do, namely,
launch the syslogger before we open postmaster sockets so that our
messages about the sockets end up in the syslogger files. That
commit fell foul of a bunch of subtle issues caused by trying to
launch a postmaster child process before creating shared memory.
Rather than messing with that interaction, let's postpone opening
the sockets till after we launch the syslogger.
This would not have been terribly safe before commit 7de19fbc0,
because we relied on socket opening to detect whether any competing
postmasters were using the same port number. But now that we choose
IPC keys without regard to the port number, there's no interaction
to worry about.
Also delay creation of the external PID file (if requested) till after
the sockets are open, since external code could plausibly be relying
on that ordering of events. And postpone most of the work of
RemovePgTempFiles() so that that potentially-slow processing still
happens after we make the external PID file. We have to be a bit
careful about that last though: as noted in the discussion subsequent to
bug #15804, EXEC_BACKEND builds still have to clear the parameter-file
temp dir before launching the syslogger.
Patch by me; thanks to Michael Paquier for review/testing.
Discussion: https://postgr.es/m/15804-3721117bf40fb654@postgresql.org
When building statistics, we need to decide how many rows to sample and
how accurate the resulting statistics should be. Until now, it was not
possible to explicitly define statistics target for extended statistics
objects, the value was always computed from the per-attribute targets
with a fallback to the system-wide default statistics target.
That's a bit inconvenient, as it ties together the statistics target set
for per-column and extended statistics. In some cases it may be useful
to require larger sample / higher accuracy for extended statics (or the
other way around), but with this approach that's not possible.
So this commit introduces a new command, allowing to specify statistics
target for individual extended statistics objects, overriding the value
derived from per-attribute targets (and the system default).
ALTER STATISTICS stat_name SET STATISTICS target_value;
When determining statistics target for an extended statistics object we
first look at this explicitly set value. When this value is -1, we fall
back to the old formula, looking at the per-attribute targets first and
then the system default. This means the behavior is backwards compatible
with older PostgreSQL releases.
Author: Tomas Vondra
Discussion: https://postgr.es/m/20190618213357.vli3i23vpkset2xd@development
Reviewed-by: Kirk Jamison, Dean Rasheed
Up to now, async.c scanned its whole array of per-backend state
whenever it needed to find listening backends. That's expensive
if MaxBackends is large, so extend the data structure with list
links that thread the active entries together.
A downside of this change is that asyncQueueUnregister (unregister
a listening backend at backend exit) now requires exclusive not shared
lock, and it can take awhile if there are many other listening
backends. We could improve the latter issue by using a doubly- not
singly-linked list, but it's probably not worth the storage space;
typical usage patterns for LISTEN/NOTIFY have fairly long-lived
listeners.
In return for that, Exec_ListenPreCommit (initially register a
listening backend), SignalBackends, and asyncQueueAdvanceTail
get significantly faster when MaxBackends is much larger than
the number of listening backends. If most of the potential
backend slots are listening, we don't win, but that's a case
where the actual interprocess-signal overhead is going to swamp
these considerations anyway.
Martijn van Oosterhout, hacked a bit more by me
Discussion: https://postgr.es/m/CADWG95vtRBFDdrx1JdT1_9nhOFw48KaeTev6F_LtDQAFVpSPhA@mail.gmail.com
Assert that _bt_binsrch() binary searches with scantid set in insertion
scankey cannot be performed on leaf pages. Leaf-level binary searches
where scantid is set must use _bt_binsrch_insert() instead.
_bt_binsrch_insert() is likely to have additional responsibilities in
the future, such as searching within GIN-style posting lists using
scantid. It seems like a good idea to tighten things up now.
In ad0bda5d24 I changed the EvalPlanQual machinery to store
substitution tuples in slot, instead of using plain HeapTuples. The
main motivation for that was that using HeapTuples will be inefficient
for future tableams. But it turns out that that conversion was buggy
for non-locking rowmarks - the wrong tuple descriptor was used to
create the slot.
As a secondary issue 5db6df0c0 changed ExecLockRows() to begin EPQ
earlier, to allow to fetch the locked rows directly into the EPQ
slots, instead of having to copy tuples around. Unfortunately, as Tom
complained, that forces some expensive initialization to happen
earlier.
As a third issue, the test coverage for EPQ was clearly insufficient.
Fixing the first issue is unfortunately not trivial: Non-locked row
marks were fetched at the start of EPQ, and we don't have the type
information for the rowmarks available at that point. While we could
change that, it's not easy. It might be worthwhile to change that at
some point, but to fix this bug, it seems better to delay fetching
non-locking rowmarks when they're actually needed, rather than
eagerly. They're referenced at most once, and in cases where EPQ
fails, might never be referenced. Fetching them when needed also
increases locality a bit.
To be able to fetch rowmarks during execution, rather than
initialization, we need to be able to access the active EPQState, as
that contains necessary data. To do so move EPQ related data from
EState to EPQState, and, only for EStates creates as part of EPQ,
reference the associated EPQState from EState.
To fix the second issue, change EPQ initialization to allow use of
EvalPlanQualSlot() to be used before EvalPlanQualBegin() (but
obviously still requiring EvalPlanQualInit() to have been done).
As these changes made struct EState harder to understand, e.g. by
adding multiple EStates, significantly reorder the members, and add a
lot more comments.
Also add a few more EPQ tests, including one that fails for the first
issue above. More is needed.
Reported-By: yi huang
Author: Andres Freund
Reviewed-By: Tom Lane
Discussion:
https://postgr.es/m/CAHU7rYZo_C4ULsAx_LAj8az9zqgrD8WDd4hTegDTMM1LMqrBsg@mail.gmail.comhttps://postgr.es/m/24530.1562686693@sss.pgh.pa.us
Backpatch: 12-, where the EPQ changes were introduced
f2e40380 introduces support of non-key attributes in GiST indexes. Then if
get_index_column_opclass() is asked by gistproperty() to get an opclass of
non-key column, it returns garbage past oidvector value. This commit fixes
that by making get_index_column_opclass() return InvalidOid in this case.
Discussion: https://postgr.es/m/20190902231948.GA5343%40alvherre.pgsql
Author: Nikita Glukhov, Alexander Korotkov
Backpatch-through: 12
Some of these are quite old, but that doesn't make them not bugs.
We'd rather report a failure via elog than SIGSEGV.
While at it, uniformly spell the error check as !RelationIsValid(rel)
rather than a bare rel == NULL test. The machine code is the same
but it seems better to be consistent.
Coverity complained about this today, not sure why, because the
mistake is in fact old.
In order to implement NULL LAST semantic GiST previously assumed distance to
the NULL value to be Inf. However, our distance functions can return Inf and
NaN for non-null values. In such cases, NULL LAST semantic appears to be
broken. This commit fixes that by introducing separate array of null flags for
distances.
Backpatch to all supported versions.
Discussion: https://postgr.es/m/CAPpHfdsNvNdA0DBS%2BwMpFrgwT6C3-q50sFVGLSiuWnV3FqOJuQ%40mail.gmail.com
Author: Alexander Korotkov
Backpatch-through: 9.4
Previously plain float comparison was used in GiST pairing heap. Such
comparison doesn't provide proper ordering for value sets containing Inf and Nan
values. This commit fixes that by usage of float8_cmp_internal(). Note, there
is remaining problem with NULL distances, which are represented as Inf in
pairing heap. It would be fixes in subsequent commit.
Backpatch to all supported versions.
Reported-by: Andrey Borodin
Discussion: https://postgr.es/m/CAPpHfdsNvNdA0DBS%2BwMpFrgwT6C3-q50sFVGLSiuWnV3FqOJuQ%40mail.gmail.com
Author: Alexander Korotkov
Reviewed-by: Heikki Linnakangas
Backpatch-through: 9.4
When using COMMIT AND CHAIN or ROLLBACK AND CHAIN not in an explicit
transaction block, the previous implementation would leave a
transaction block active in the ROLLBACK case but not the COMMIT case.
To fix for now, error out when using these commands not in an explicit
transaction block. This restriction could be lifted if a sensible
definition and implementation is found.
Bug: #15977
Author: fn ln <emuser20140816@gmail.com>
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
Commit 6f6b99d13 stuck an INFO message into the fast path for
checking partition constraints, for no very good reason except
that it made it easy for the regression tests to verify that
that path was taken. Assorted later patches did likewise,
increasing the unsuppressable-chatter level from ALTER TABLE
even more. This isn't good for the user experience, so let's
drop these messages down to DEBUG1 where they belong. So as
not to have a loss of test coverage, create a TAP test that
runs the relevant queries with client_min_messages = DEBUG1
and greps for the expected messages.
This testing method is a bit brute-force --- in particular,
it duplicates the execution of a fair amount of the core
create_table and alter_table tests. We experimented with
other solutions, but running any significant amount of
standard testing with client_min_messages = DEBUG1 seems
to have a lot of output-stability pitfalls, cf commits
bbb96c370 and 5655565c0. Possibly at some point we'll look
into whether we can reduce the amount of test duplication.
Backpatch into v12, because some of these messages are new
in v12 and we don't really want to ship it that way.
Sergei Kornilov
Discussion: https://postgr.es/m/81911511895540@web58j.yandex.ru
Discussion: https://postgr.es/m/4859321552643736@myt5-02b80404fd9e.qloud-c.yandex.net
As a result of some long-ago quick hacks, the SIMILAR TO operator
and the corresponding flavor of substring() interpreted "ESCAPE NULL"
as selecting the default escape character '\'. This is both
surprising and not per spec: the standard is clear that these
functions should return NULL for NULL input.
Additionally, because of inconsistency of the strictness markings
of 3-argument substring() and similar_escape(), the planner could not
inline the SQL definition of substring(), resulting in a substantial
performance penalty compared to the underlying POSIX substring()
function.
The simplest fix for this would be to change the strictness marking
of similar_escape(), but if we do that we risk breaking existing views
that depend on that function. Hence, leave similar_escape() as-is
as a compatibility function, and instead invent a new function
similar_to_escape() that comes in two strict variants.
There are a couple of other behaviors in this area that are also
not per spec, but they are documented and seem generally at least
as sane as the spec's definition, so leave them alone. But improve
the documentation to describe them fully.
Patch by me; thanks to Álvaro Herrera and Andrew Gierth for review
and discussion.
Discussion: https://postgr.es/m/14047.1557708214@sss.pgh.pa.us
This moves much of the non-heap-specific logic from toast_delete and
toast_insert_or_update into a helper functions accessible via a new
header, toast_helper.h. Using the functions in this module, a table
AM can implement creation and deletion of TOAST table rows with
much less code duplication than was possible heretofore. Some
table AMs won't want to use the TOAST logic at all, but for those
that do this will make that easier.
Patch by me, reviewed and tested by Prabhat Sabu, Thomas Munro,
Andres Freund, and Álvaro Herrera.
Discussion: http://postgr.es/m/CA+TgmoZv-=2iWM4jcw5ZhJeL18HF96+W1yJeYrnGMYdkFFnEpQ@mail.gmail.com
The old code didn't differentiate between a read error and a
concurrent truncation. fread reports both of these by returning 0;
you have to use feof() or ferror() to distinguish between them,
which this code did not do.
It might be a better idea to use read() rather than fread() here,
so that we can display a less-generic error message, but I'm not
sure that would qualify as a back-patchable bug fix, so just do
this much for now.
Jeevan Chalke, reviewed by Jeevan Ladhe and by me.
Discussion: http://postgr.es/m/CA+TgmobG4ywMzL5oQq2a8YKp8x2p3p1LOMMcGqpS7aekT9+ETA@mail.gmail.com
Previously even if postmaster died and WaitLatch() woke up with that event
while pg_promote() was waiting for the standby promotion to finish,
pg_promote() did nothing special and kept waiting until timeout occurred.
This could cause a busy loop.
This patch make pg_promote() return false immediately when postmaster
dies, to avoid such a busy loop.
Back-patch to v12 where pg_promote() was added.
Author: Fujii Masao
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/CAHGQGwEs9ROgSp+QF+YdDU+xP8W=CY1k-_Ov-d_Z3JY+to3eXA@mail.gmail.com
This approach provides a much tighter binding between a data directory
and the associated SysV shared memory block (and SysV or named-POSIX
semaphores, if we're using those). Key collisions are still possible,
but only between data directories stored on different filesystems,
so the situation should be negligible in practice. More importantly,
restarting the postmaster with a different port number no longer
risks failing to identify a relevant shared memory block, even when
postmaster.pid has been removed. A standalone backend is likewise
much more certain to detect conflicting leftover backends.
(In the longer term, we might now think about deprecating the port as
a cluster-wide value, so that one postmaster could support sockets
with varying port numbers. But that's for another day.)
The hazards fixed here apply only on Unix systems; our Windows code
paths already use identifiers derived from the data directory path
name rather than the port.
src/test/recovery/t/017_shm.pl, which intends to test key-collision
cases, has been substantially rewritten since it can no longer use
two postmasters with identical port numbers to trigger the case.
Instead, use Perl's IPC::SharedMem module to create a conflicting
shmem segment directly. The test script will be skipped if that
module is not available. (This means that some older buildfarm
members won't run it, but I don't think that that results in any
meaningful coverage loss.)
Patch by me; thanks to Noah Misch and Peter Eisentraut for discussion
and review.
Discussion: https://postgr.es/m/16908.1557521200@sss.pgh.pa.us
detoast.c/h contain functions required to detoast a datum, partially
or completely, plus a few other utility functions for examining the
size of toasted datums.
toast_internals.c/h contain functions that are used internally to the
TOAST subsystem but which (mostly) do not need to be accessed from
outside.
heaptoast.c/h contains code that is intrinsically specific to the
heap AM, either because it operates on HeapTuples or is based on the
layout of a heap page.
detoast.c and toast_internals.c are placed in
src/backend/access/common rather than src/backend/access/heap. At
present, both files still have dependencies on the heap, but that will
be improved in a future commit.
Patch by me, reviewed and tested by Prabhat Sabu, Thomas Munro,
Andres Freund, and Álvaro Herrera.
Discussion: http://postgr.es/m/CA+TgmoZv-=2iWM4jcw5ZhJeL18HF96+W1yJeYrnGMYdkFFnEpQ@mail.gmail.com
Use the explicit_bzero() function in places where it is important that
security information such as passwords is cleared from memory. There
might be other places where it could be useful; this is just an
initial collection.
For platforms that don't have explicit_bzero(), provide various
fallback implementations. (explicit_bzero() itself isn't standard,
but as Linux/glibc, FreeBSD, and OpenBSD have it, it's the most common
spelling, so it makes sense to make that the invocation point.)
Discussion: https://www.postgresql.org/message-id/flat/42d26bde-5d5b-c90d-87ae-6cab875f73be%402ndquadrant.com
The logic ending progress reporting for a backend entry introduced by
b6fb647 causes callers of pgstat_progress_end_command() to do some extra
work when track_activities is enabled as the process fields are reset in
the backend entry even if no command were started for reporting.
This resets the fields only if a command is registered for progress
reporting, and only if track_activities is enabled.
Author: Masahiho Sawada
Discussion: https://postgr.es/m/CAD21AoCry_vJ0E-m5oxJXGL3pnos-xYGCzF95rK5Bbi3Uf-rpA@mail.gmail.com
Backpatch-through: 9.6
This function is only used by xlogreader.c itself, so there's no need to
export it. It was introduced by commit 3b02ea4f07 with the apparent
intention that it could be used externally, but I couldn't find any
external code calling it.
I (Álvaro) couldn't resist the urge to sort nearby function prototypes
properly while at it.
Author: Antonin Houska
Discussion: https://postgr.es/m/14984.1554998742@spoje.net
The message was included as a parameter when this function was added in
dcb2bda9b7, but I don't think it has ever served any useful purpose.
Let's stop spreading it pointlessly.
Reviewed by Amit Langote and Peter Eisentraut.
Discussion: https://postgr.es/m/20190806224728.GA17233@alvherre.pgsql
The leak happens in str_tolower, str_toupper and str_initcap, which are
used in several places including their equivalent SQL-level functions,
and can only be triggered when using an ICU-provided collation when
converting the input string.
b615920 fixed a similar leak. Backpatch down 10 where ICU collations
have been introduced.
Author: Konstantin Knizhnik
Discussion: https://postgr.es/m/94c0ad0a-cbc2-e4a3-7829-2bdeaf9146db@postgrespro.ru
Backpatch-through: 10
In what seems like a fit of misplaced optimization,
ExtractReplicaIdentity() accessed the relation's replica-identity
index without taking any lock on it. Usually, the surrounding query
already holds some lock so this is safe enough ... but in the case
of a previously-planned delete, there might be no existing lock.
Given a suitable test case, this is exposed in v12 and HEAD by an
assertion added by commit b04aeb0a0.
The whole thing's rather poorly thought out anyway; rather than
looking directly at the index, we should use the index-attributes
bitmap that's held by the parent table's relcache entry, as the
caller functions do. This is more consistent and likely a bit
faster, since it avoids a cache lookup. Hence, change to doing it
that way.
While at it, rather than blithely assuming that the identity
columns are non-null (with catastrophic results if that's wrong),
add assertion checks that they aren't null. Possibly those should
be actual test-and-elog, but I'll leave it like this for now.
In principle, this is a bug that's been there since this code was
introduced (in 9.4). In practice, the risk seems quite low, since
we do have a lock on the index's parent table, so concurrent
changes to the index's catalog entries seem unlikely. Given the
precedent that commit 9c703c169 wasn't back-patched, I won't risk
back-patching this further than v12.
Per report from Hadi Moshayedi.
Discussion: https://postgr.es/m/CAK=1=Wrek44Ese1V7LjKiQS-Nd-5LgLi_5_CskGbpggKEf3tKQ@mail.gmail.com
The comment did not match what the code actually did for integers with
the 43rd bit set. You get an integer like that, if you have a posting
list with two adjacent TIDs that are more than 2^31 blocks apart.
According to the comment, we would store that in 6 bytes, with no
continuation bit on the 6th byte, but in reality, the code encodes it
using 7 bytes, with a continuation bit on the 6th byte as normal.
The decoding routine also handled these 7-byte integers correctly, except
for an overflow check that assumed that one integer needs at most 6 bytes.
Fix the overflow check, and fix the comment to match what the code
actually does. Also fix the comment that claimed that there are 17 unused
bits in the 64-bit representation of an item pointer. In reality, there
are 64-32-11=21.
Fitting any item pointer into max 6 bytes was an important property when
this was written, because in the old pre-9.4 format, item pointers were
stored as plain arrays, with 6 bytes for every item pointer. The maximum
of 6 bytes per integer in the new format guaranteed that we could convert
any page from the old format to the new format after upgrade, so that the
new format was never larger than the old format. But we hardly need to
worry about that anymore, and running into that problem during upgrade,
where an item pointer is expanded from 6 to 7 bytes such that the data
doesn't fit on a page anymore, is implausible in practice anyway.
Backpatch to all supported versions.
This also includes a little test module to test these large distances
between item pointers, without requiring a 16 TB table. It is not
backpatched, I'm including it more for the benefit of future development
of new posting list formats.
Discussion: https://www.postgresql.org/message-id/33bfc20a-5c86-f50c-f5a5-58e9925d05ff%40iki.fi
Reviewed-by: Masahiko Sawada, Alexander Korotkov
RelationAllowsEarlyPruning() performed a catalog scan, but is used
in two contexts where that was a bad idea:
1. In heap_page_prune_opt(), which runs very frequently in some large
scans. This caused major performance problems in a field report
that was easy to reproduce.
2. In TestForOldSnapshot(), which runs while we hold a buffer content
lock. It's not clear if this was guaranteed to be free of buffer
deadlock risk.
The check was introduced in commit 2cc41acd8 and defended against a
real problem: 9.6's hash indexes have no page LSN and so we can't
allow early pruning (ie the snapshot-too-old feature). We can remove
the check from all later releases though: hash indexes are now logged,
and there is no way to create UNLOGGED indexes on regular logged
tables.
If a future release allows such a combination, it might need to put
a similar check in place, but it'll need some more thought.
Back-patch to 10.
Author: Thomas Munro
Reviewed-by: Tom Lane, who spotted the second problem
Discussion: https://postgr.es/m/CA%2BhUKGKT8oTkp5jw_U4p0S-7UG9zsvtw_M47Y285bER6a2gD%2Bg%40mail.gmail.com
Discussion: https://postgr.es/m/CAA4eK1%2BWy%2BN4eE5zPm765h68LrkWc3Biu_8rzzi%2BOYX4j%2BiHRw%40mail.gmail.com
Commit efada2b8e9, which made the nbtree page deletion algorithm more
robust, removed the concept of a half-dead internal page. Remove a
comment about half dead parent pages that was overlooked.
An empty file name or subdirectory name leads join_path_components() to
just produce the parent directory name, which leads to weird failures or
recursive inclusions. Let's throw a specific error for that. It takes
only slightly more code to detect all-blank names, so do so.
Also, detect direct recursion, ie a file calling itself. As coded
this will also detect recursion via "include_dir '.'", which is
perhaps more likely than explicitly including the file itself.
Detecting indirect recursion would require API changes for guc-file.l
functions, which seems not worth it since extensions might call them.
The nesting depth limit will catch such cases eventually, just not
with such an on-point error message.
In passing, adjust the example usages in postgresql.conf.sample
to perhaps eliminate the problem at the source: there's no reason
for the examples to suggest that an empty value is valid.
Per a trouble report from Brent Bates. Back-patch to 9.5; the
issue is old, but the code in 9.4 is enough different that the
patch doesn't apply easily, and it doesn't seem worth the trouble
to fix there.
Ian Barwick and Tom Lane
Discussion: https://postgr.es/m/8c8bcbca-3bd9-dc6e-8986-04a5abdef142@2ndquadrant.com
A report from Alvaro Herrera shows that if we're in PM_STARTUP
state, and we spawn a dead_end child to reject some incoming
connection request, and that child dies with an unexpected exit
code, the postmaster does not respond well. We correctly send
SIGQUIT to the startup process, but then:
* if the startup process exits with nonzero exit code, as expected,
we thought that that indicated a crash and aborted startup.
* if the startup process exits with zero exit code, which is possible
due to the inherent race condition, we'd advance to PM_RUN state
which is fine --- but the code forgot that AbortStartTime would be
nonzero in this situation. We'd either die on the Asserts saying
that it was zero, or perhaps misbehave later on. (A quick look
suggests that the only misbehavior might be busy-waiting due to
DetermineSleepTime doing the wrong thing.)
To fix the first point, adjust the state-machine logic to recognize
that a nonzero exit code is expected after sending SIGQUIT, and have
it transition to a state where we can restart the startup process.
To fix the second point, change the Asserts to clear the variable
rather than just claiming it should be clear already.
Perhaps we could improve this further by not treating a crash of
a dead_end child as a reason for panic'ing the database. However,
since those child processes are connected to shared memory, that
seems a bit risky. There are few good reasons for a dead_end child
to report failure anyway (the cause of this in Alvaro's report is
quite unclear). On balance, therefore, a minimal fix seems best.
This is an oversight in commit 45811be94. While that was back-patched,
I'm hesitant to back-patch this change. The lack of reasons for a
dead_end child to fail suggests that the case should be very rare in
the field, which squares with the lack of reports; so it seems like
this might not be worth the risk of introducing new issues. In any
case we can let it bake awhile in HEAD before considering a back-patch.
Discussion: https://postgr.es/m/20190615160950.GA31378@alvherre.pgsql
Bleeding-edge LLVM has stopped supplying replacements for various
C++14 library features, for people on older C++ versions. Since we're
not ready to require C++14 yet, just use plain old new instead of
make_unique. As revealed by buildfarm animal seawasp.
Back-patch to 11.
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/CA%2BhUKGJWG7unNqmkxg7nC5o3o-0p2XP6co4r%3D9epqYMm8UY4Mw%40mail.gmail.com
The Postgres approach to coupling locks during an ascent of the tree is
slightly different to the approach taken by Lehman and Yao. Add a new
paragraph to the "Differences to the Lehman & Yao algorithm" section of
the nbtree README that explains the similarities and differences.
Adjust the struct comment that describes how page splits use their
descent stack to cascade up the tree from the leaf level.
In passing, fix up some unrelated nbtree comments that had typos or were
obsolete.
In early development patches, "replication origins" were called "identifiers";
almost everything was renamed, but these references to the old terminology
went unnoticed.
Reported-by: Craig Ringer
If the record argument is NULL and has no declared type more concrete
than RECORD, we can't extract useful information about the desired
rowtype from it. In this case, see if we're in FROM with an AS clause,
and if so extract the needed rowtype info from AS.
It worked like this before v11, but commit 37a795a60 removed the
behavior, reasoning that it was undocumented, inefficient, and utterly
not self-consistent. If you want to take type info from an AS clause,
you should be using the json_to_record() family of functions not the
json_populate_record() family. Also, it was already the case that
the "populate" functions would fail for a null-valued RECORD input
(with an unfriendly "record type has not been registered" error)
when there wasn't an AS clause at hand, and it wasn't obvious that
that behavior wasn't OK when there was one. However, it emerges
that some people were depending on this to work, and indeed the
rather off-point error message you got if you left off AS encouraged
slapping on AS without switching to the json_to_record() family.
Hence, put back the fallback behavior of looking for AS. While at it,
improve the run-time error you get when there's no place to obtain type
info; we can do a lot better than "record type has not been registered".
(We can't, unfortunately, easily improve the parse-time error message
that leads people down this path in the first place.)
While at it, I refactored the code a bit to avoid duplicating the
same logic in several different places.
Per bug #15940 from Jaroslav Sivy. Back-patch to v11 where the
current coding came in. (The pre-v11 deficiencies in this area
aren't regressions, so we'll leave those branches alone.)
Patch by me, based on preliminary analysis by Dmitry Dolgov.
Discussion: https://postgr.es/m/15940-2ab76dc58ffb85b6@postgresql.org
Prefix inet_net_ntop and sibling routines with "pg_" to ensure that
they aren't mistaken for C-library functions. This fixes warnings
from cpluspluscheck on some platforms, and should help reduce reader
confusion everywhere, since our functions aren't exactly interchangeable
with the library versions (they may have different ideas about address
family codes).
This shouldn't be fixing any actual bugs, unless somebody's linker
is misbehaving, so no need to back-patch.
Discussion: https://postgr.es/m/20518.1559494394@sss.pgh.pa.us
Remove use of "register" keyword in hashfn.c. It's obsolescent
according to recent C++ compilers, and no modern C compiler pays
much attention to it either.
Also fix one cosmetic warning about signed vs unsigned comparison.
Discussion: https://postgr.es/m/20518.1559494394@sss.pgh.pa.us
If a table inherits from multiple unrelated parents, we must disallow
changing the type of a column inherited from multiple such parents, else
it would be out of step with the other parents. However, it's possible
for the column to ultimately be inherited from just one common ancestor,
in which case a change starting from that ancestor should still be
allowed. (I would not be excited about preserving that option, were
it not that we have regression test cases exercising it already ...)
It's slightly annoying that this patch looks different from the logic
with the same end goal in renameatt(), and more annoying that it
requires an extra syscache lookup to make the test. However, the
recursion logic is quite different in the two functions, and a
back-patched bug fix is no place to be trying to unify them.
Per report from Manuel Rigger. Back-patch to 9.5. The bug exists in
9.4 too (and doubtless much further back); but the way the recursion
is done in 9.4 is a good bit different, so that substantial refactoring
would be needed to fix it in 9.4. I'm disinclined to do that, or risk
introducing new bugs, for a bug that has escaped notice for this long.
Discussion: https://postgr.es/m/CA+u7OA4qogDv9rz1HAb-ADxttXYPqQdUdPY_yd4kCzywNxRQXA@mail.gmail.com
For most uses of acl.h the details of how "Acl" internally looks like
are irrelevant. It might make sense to move a lot of the
implementation details into a separate header at a later point.
The main motivation of this change is to avoid including fmgr.h (via
array.h, which needs it for exposed structs) in a lot of files that
otherwise don't need it. A subsequent commit will remove the fmgr.h
include from a lot of files.
Directly include utils/array.h and utils/expandeddatum.h from the
files that need them, but previously included them indirectly, via
acl.h.
Author: Andres Freund
Discussion: https://postgr.es/m/20190803193733.g3l3x3o42uv4qj7l@alap3.anarazel.de
Commit 4b93f5799 rearranged things in plpgsql to make it cope better with
composite types changing underneath it intra-session. However, I failed to
consider the case of a composite type being dropped and recreated entirely.
In my defense, the previous coding didn't consider that possibility at all
either --- but it would accidentally work so long as you didn't change the
type's field list, because the built-at-compile-time list of component
variables would then still match the type's new definition. The new
coding, however, occasionally tries to re-look-up the type by OID, and
then fails to find the dropped type.
To fix this, we need to save the TypeName struct, and then redo the type
OID lookup from that. Of course that's expensive, so we don't want to do
it every time we need the type OID. This can be fixed in the same way that
4b93f5799 dealt with changes to composite types' definitions: keep an eye
on the type's typcache entry to see if its tupledesc has been invalidated.
(Perhaps, at some point, this mechanism should be generalized so it can
work for non-composite types too; but for now, plpgsql only tries to
cope with intra-session redefinitions of composites.)
I'm slightly hesitant to back-patch this into v11, because it changes
the contents of struct PLpgSQL_type as well as the signature of
plpgsql_build_datatype(), so in principle it could break code that is
poking into the innards of plpgsql. However, the only popular extension
of that ilk is pldebugger, and it doesn't seem to be affected. Since
this is a regression for people who were relying on the old behavior,
it seems worth taking the small risk of causing compatibility issues.
Per bug #15913 from Daniel Fiori. Back-patch to v11 where 4b93f5799
came in.
Discussion: https://postgr.es/m/15913-a7e112e16dedcffc@postgresql.org
Previously, async.c got rid of duplicate notifications by scanning
the list of pending events to compare each one to the proposed new
event. This works okay for very small numbers of distinct events,
but degrades as O(N^2) for many events. We can improve matters by
using a hash table to probe for duplicates. So as not to add a
lot of overhead for the simple cases that the code did handle well
before, create the hash table only once a (sub)transaction has
queued more than 16 distinct notify events.
A downside is that we now have to do per-event work to propagate
a successful subtransaction's notify events up to its parent.
(But this isn't significant unless the subtransaction had many
events, in which case the O(N^2) behavior would have been in
play already, so we still come out ahead.)
We can make some lemonade out of this lemon, though: since we must
examine each event anyway, it's now possible to de-duplicate events
fully, rather than skipping that for events merged up from
subtransactions. Hence, remove the old weasel wording in notify.sgml
about whether de-duplication happens or not, and adjust the test
case in async-notify.spec that exhibited the old behavior.
While at it, rearrange the definition of struct Notification to make
it more compact and require just one palloc per event, rather than
two or three. This saves space when there are a lot of events,
in fact more than enough to buy back the space needed for the hash
table.
Patch by me, based on discussions around a different patch
submitted by Filip Rembiałkowski.
Discussion: https://postgr.es/m/17822.1564186806@sss.pgh.pa.us
ALTER SYSTEM itself normally won't make duplicate entries (although
up till this patch, it was possible to confuse it by writing case
variants of a GUC's name). However, if some external tool has appended
entries to the file, that could result in duplicate entries for a single
GUC name. In such a situation, ALTER SYSTEM did exactly the wrong thing,
because it replaced or removed only the first matching entry, leaving
the later one(s) still there and hence still determining the active value.
This patch fixes that by making ALTER SYSTEM sweep through the file and
remove all matching entries, then (if not ALTER SYSTEM RESET) append the
new setting to the end. This means entries will be in order of last
setting rather than first setting, but that shouldn't hurt anything.
Also, make the comparisons case-insensitive so that the right things
happen if you do, say, ALTER SYSTEM SET "TimeZone" = 'whatever'.
This has been broken since ALTER SYSTEM was invented, so back-patch
to all supported branches.
Ian Barwick, with minor mods by me
Discussion: https://postgr.es/m/aed6cc9f-98f3-2693-ac81-52bb0052307e@2ndquadrant.com
The initial value of the nbtree stack downlink block number field
recorded during an initial descent of the tree wasn't actually used.
Both _bt_getstackbuf() callers overwrote the value with their own value.
Remove the block number field from the stack struct, and add a child
block number argument to _bt_getstackbuf() in its place. This makes the
overall design of _bt_getstackbuf() clearer.
Author: Peter Geoghegan
Reviewed-By: Anastasia Lubennikova
Discussion: https://postgr.es/m/CAH2-Wzmx+UbXt2YNOUCZ-a04VdXU=S=OHuAuD7Z8uQq-PXTYUg@mail.gmail.com
Commit d2086b08b0 removed almost all cases where nbtree must release a
read buffer lock and acquire a write buffer lock instead, so remaining
cases in which that's still necessary are not notable enough to appear
in the nbtree README.
More importantly, holding on to a buffer pin in cases where nbtree must
trade a read lock for a write lock is very unlikely to save any I/O.
This seems to have been a long overlooked throwback to a time when
nbtree cared about write-ordering dependencies, and performed
synchronous buffer writes. It hasn't worked that way in many years.
Use the PageIndexTupleOverwrite() bufpage.c routine within nbtree
instead of deleting a tuple and re-inserting its replacement. This
makes the intent of affected code slightly clearer. It also makes
CREATE INDEX slightly faster, since there is no longer a need to shift
every leaf page's line pointer array back and forth during index builds.
Author: Peter Geoghegan, Anastasia Lubennikova
Reviewed-By: Anastasia Lubennikova
Discussion: https://postgr.es/m/CAH2-Wz=Zk=B9+Vwm376WuO7YTjFc2SSskifQm4Nme3RRRPtOSQ@mail.gmail.com
We only need to invoke constraint exclusion on partitioned tables when
they are a partition, and they themselves contain a default partition;
it's not necessary otherwise, and it's expensive, so avoid it. Also, we
were trying once for each clause separately, but we can do it for all
the clauses at once.
While at it, centralize setting of RelOptInfo->partition_qual instead of
computing it in slightly different ways in different places.
Per complaints from Simon Riggs about 4e85642d935e; reviewed by Yuzuko
Hosoya, Kyotaro Horiguchi.
Author: Amit Langote. I (Álvaro) again mangled the patch somewhat.
Discussion: https://postgr.es/m/CANP8+j+tMCY=nEcQeqQam85=uopLBtX-2vHiLD2bbp7iQQUKpA@mail.gmail.com
As coded, the ICU-collation path in pattern_char_isalpha() failed
to consider regular ASCII letters to be case-varying. This led to
like_fixed_prefix treating too much of an ILIKE pattern as being a
fixed prefix, so that indexscans derived from an ILIKE clause might
miss entries that they should find.
Per bug #15892 from James Inform. This is an oversight in the original
ICU patch (commit eccfef81e), so back-patch to v10 where that came in.
Discussion: https://postgr.es/m/15892-e5d2bea3e8a04a1b@postgresql.org
Now that list_nth is O(1), there's no good reason to maintain a
separate array of RTE pointers rather than indexing into
estate->es_range_table. Deleting the array doesn't save all that
much either; but just on cleanliness grounds, it's better not to
have duplicate representations of the identical information.
Discussion: https://postgr.es/m/14960.1565384592@sss.pgh.pa.us
In the wake of commit 1cff1b95a, the result of list_concat no longer
shares the ListCells of the second input. Therefore, we can replace
"list_concat(x, list_copy(y))" with just "list_concat(x, y)".
To improve call sites that were list_copy'ing the first argument,
or both arguments, invent "list_concat_copy()" which produces a new
list sharing no ListCells with either input. (This is a bit faster
than "list_concat(list_copy(x), y)" because it makes the result list
the right size to start with.)
In call sites that were not list_copy'ing the second argument, the new
semantics mean that we are usually leaking the second List's storage,
since typically there is no remaining pointer to it. We considered
inventing another list_copy variant that would list_free the second
input, but concluded that for most call sites it isn't worth worrying
about, given the relative compactness of the new List representation.
(Note that in cases where such leakage would happen, the old code
already leaked the second List's header; so we're only discussing
the size of the leak not whether there is one. I did adjust two or
three places that had been troubling to free that header so that
they manually free the whole second List.)
Patch by me; thanks to David Rowley for review.
Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
We have implemented jsonpath string comparison using default database locale.
However, standard requires us to compare Unicode codepoints. This commit
implements that, but for performance reasons we still use per-byte comparison
for "==" operator. Thus, for consistency other comparison operators do per-byte
comparison if Unicode codepoints appear to be equal.
In some edge cases, when same Unicode codepoints have different binary
representations in database encoding, we diverge standard to achieve better
performance of "==" operator. In future to implement strict standard
conformance, we can do normalization of input JSON strings.
Original patch was written by Nikita Glukhov, rewritten by me.
Reported-by: Markus Winand
Discussion: https://postgr.es/m/8B7FA3B4-328D-43D7-95A8-37B8891B8C78%40winand.at
Author: Nikita Glukhov, Alexander Korotkov
Backpatch-through: 12
This failed with either "tuple already updated by self" or "duplicate
key value violates unique constraint", depending on whether the table
had previously been analyzed or not. The reason is that ANALYZE tried
to insert or update the same pg_statistic rows twice, and there was no
CommandCounterIncrement between. So add one. The same case works fine
outside a transaction block, because then there's a whole transaction
boundary between, as a consequence of the way VACUUM works.
This issue has been latent all along, but the problem was unreachable
before commit 11d8d72c2 added the ability to specify multiple tables
in ANALYZE. We could, perhaps, alternatively fix it by adding code to
de-duplicate the list of VacuumRelations --- but that would add a
lot of overhead to work around dumb commands, so it's not attractive.
Per bug #15946 from Yaroslav Schekin. Back-patch to v11.
(Note: in v11 I also back-patched the test added by commit 23224563d;
otherwise the problem doesn't manifest in the test I added, because
"vactst" is empty when the tests for multiple ANALYZE targets are
reached. That seems like not a very good thing anyway, so I did this
rather than rethinking the choice of test case.)
Discussion: https://postgr.es/m/15946-5c7570a2884a26cf@postgresql.org
Rename the "tupindex" field from tuplesort.c's SortTuple struct to
"srctape", since it can only ever be used to store a source/input tape
number when merging external sort runs. This has been the case since
commit 8b304b8b72, which removed replacement selection sort from
tuplesort.c.
Merge setup_append_rel_array into setup_simple_rel_arrays. There's no
particularly good reason to keep them separate, and it's inconsistent
with the lack of separation in expand_planner_arrays. The only apparent
benefit was that the fast path for trivial queries in query_planner()
doesn't need to set up the append_rel_array; but all we're saving there
is an if-test and NULL assignment, which surely ought to be negligible.
Also improve some obsolete comments.
Discussion: https://postgr.es/m/17220.1565301350@sss.pgh.pa.us
b654714 has reworked the way trailing CR/LF characters are removed from
strings. This commit introduces a new routine in common/string.c and
refactors the code so as the logic is in a single place, mostly.
Author: Michael Paquier
Reviewed-by: Bruce Momjian
Discussion: https://postgr.es/m/20190801031820.GF29334@paquier.xyz
READTUP() routines do not and cannot use the resettable "tuplecontext"
memory context, since it is deleted when merging begins. Update an
obsolete comment that claimed otherwise. This was an oversight in
commit e94568ecc1.
In passing, fix an unrelated tuplesort typo.
We were applying constraint exclusion on the partition constraint when
generating pruning steps for a clause, but only for the rather
restricted situation of them being boolean OR operators; however it is
possible to have differently shaped clauses that also benefit from
constraint exclusion. This applies particularly to the default
partition since their constraints are in essence a long list of OR'ed
subclauses ... but it applies to other cases too. So in certain cases
we're scanning partitions that we don't need to.
Remove the specialized code in OR clauses, and add a generally
applicable test of the clause refuting the partition constraint; mark
the whole pruning operation as contradictory if it hits.
This has the unwanted side-effect of testing some (most? all?)
constraints more than once if constraint_exclusion=on. That seems
unavoidable as far as I can tell without some additional work, but
that's not the recommended setting for that parameter anyway.
However, because this imposes additional processing cost for all
queries using partitioned tables, I decided not to backpatch this
change.
Author: Amit Langote, Yuzuko Hosoya, Álvaro Herrera
Reviewers: Shawn Wang, Thibaut Madeleine, Yoshikazu Imai, Kyotaro
Horiguchi; they were also uncredited reviewers for commit 489247b0e6.
Discussion: https://postgr.es/m/9bb31dfe-b0d0-53f3-3ea6-e64b811424cf@lab.ntt.co.jp
In serializable mode, heap_hot_search_buffer() incorrectly acquired a
predicate lock on the root tuple, not the returned tuple that satisfied
the visibility checks. As explained in README-SSI, the predicate lock does
not need to be copied or extended to other tuple versions, but for that to
work, the correct, visible, tuple version must be locked in the first
place.
The original SSI commit had this bug in it, but it was fixed back in 2013,
in commit 81fbbfe335. But unfortunately, it was reintroduced a few months
later in commit b89e151054. Wising up from that, add a regression test
to cover this, so that it doesn't get reintroduced again. Also, move the
code that sets 't_self', so that it happens at the same time that the
other HeapTuple fields are set, to make it more clear that all the code in
the loop operate on the "current" tuple in the chain, not the root tuple.
Bug spotted by Andres Freund, analysis and original fix by Thomas Munro,
test case and some additional changes to the fix by Heikki Linnakangas.
Backpatch to all supported versions (9.4).
Discussion: https://www.postgresql.org/message-id/20190731210630.nqhszuktygwftjty%40alap3.anarazel.de
When parsing a timetz string with a dynamic timezone abbreviation or a
timezone not specified, it was possible to generate incorrect timestamps
based on a date which uses some non-initialized variables if the input
string did not specify fully a date to parse. This is already checked
when a full timezone spec is included in the input string, but the two
other cases mentioned above missed the same checks.
This gets fixed by generating an error as this input is invalid, or in
short when a date is not fully specified.
Valgrind was complaining about this problem.
Bug: #15910
Author: Alexander Lakhin
Discussion: https://postgr.es/m/15910-2eba5106b9aa0c61@postgresql.org
Backpatch-through: 9.4
As of now, logical decoding of a multi-insert has been scanning all
xl_multi_insert_tuple entries only if XLH_INSERT_CONTAINS_NEW_TUPLE was
getting set in the record. This is not an issue on HEAD as multi-insert
records are not used for system catalogs, but the logical decoding logic
includes all the code necessary to handle that properly, except that the
code missed to iterate correctly over all xl_multi_insert_tuple entries
when the flag is not set. Hence, when trying to use multi-insert for
system catalogs, an assertion would be triggered.
An upcoming patch is going to make use of multi-insert for system
catalogs, and this fixes the logic to make sure that all entries are
scanned correctly without softening the existing assertions.
Reported-by: Daniel Gustafsson
Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/CBFFD532-C033-49EB-9A5A-F67EAEE9EB0B@yesql.se
Commit bf6c614a2 rearranged the lookup of the comparison operators
needed in a hashed subplan, and in so doing, broke the cross-type
case: it caused the original LHS-vs-RHS operator to be used to compare
hash table entries too (which of course are all of the RHS type).
This leads to C functions being passed a Datum that is not of the
type they expect, with the usual hazards of crashes and unauthorized
server memory disclosure.
For the set of hashable cross-type operators present in v11 core
Postgres, this bug is nearly harmless on 64-bit machines, which
may explain why it escaped earlier detection. But it is a live
security hazard on 32-bit machines; and of course there may be
extensions that add more hashable cross-type operators, which
would increase the risk.
Reported by Andreas Seltenreich. Back-patch to v11 where the
problem came in.
Security: CVE-2019-10209
Commit aa27977fe2 introduced this
restriction for pg_temp.function_name(arg); do likewise for types
created in temporary schemas. Programs that this breaks should add
"pg_temp." schema qualification or switch to arg::type_name syntax.
Back-patch to 9.4 (all supported versions).
Reviewed by Tom Lane. Reported by Tom Lane.
Security: CVE-2019-10208
Those data types use parsing and/or calculation wrapper routines which
can generate some generic error messages in the event of a failure. The
caller of these routines can also pass a pointer variable settable by
the routine to track if an error has happened, letting the caller decide
what to do in the event of an error and what error message to generate.
Those routines have been slacking the initialization of the tracking
flag, which can be confusing when reading the code, so add some
safeguards against calls of these parsing routines which could lead to a
dubious result.
The LSN parsing gains an assertion to make sure that the tracking flag
is set, while numeric and float paths initialize the flag to a saner
state.
Author: Jeevan Ladhe
Reviewed-by: Álvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/CAOgcT0NOM9oR0Hag_3VpyW0uF3iCU=BDUFSPfk9JrWXRcWQHqw@mail.gmail.com
This reverts commit 88bdbd3f74.
As committed, statement sampling used the existing duration threshold
(log_min_duration_statement) when decide which statements to sample.
The issue is that even the longest statements are subject to sampling,
and so may not end up logged. An improvement was proposed, introducing
a second duration threshold, but it would not be backwards compatible.
So we've decided to revert this feature - the separate threshold should
be part of the feature itself.
Discussion: https://postgr.es/m/CAFj8pRDS8tQ3Wviw9%3DAvODyUciPSrGeMhJi_WPE%2BEB8%2B4gLL-Q%40mail.gmail.com
This reverts commit 9dc1225855.
As committed, statement sampling used the existing duration threshold
(log_min_duration_statement) when decide which statements to sample.
The issue is that even the longest statements are subject to sampling,
and so may not end up logged. An improvement was proposed, introducing
a second duration threshold, but it would not be backwards compatible.
So we've decided to revert this feature - the separate threshold should
be part of the feature itself.
Discussion: https://postgr.es/m/CAFj8pRDS8tQ3Wviw9%3DAvODyUciPSrGeMhJi_WPE%2BEB8%2B4gLL-Q%40mail.gmail.com
When querying a partitioned table containing a default partition, we
were wrongly deciding to include it in the scan too early in the
process, failing to exclude it in some cases. If we reinterpret the
PruneStepResult.scan_default flag slightly, we can do a better job at
detecting that it can be excluded. The change is that we avoid setting
the flag for that pruning step unless the step absolutely requires the
default partition to be scanned (in contrast with the previous
arrangement, which was to set it unless the step was able to prune it).
So get_matching_partitions() must explicitly check the partition that
each returned bound value corresponds to in order to determine whether
the default one needs to be included, rather than relying on the flag
from the final step result.
Author: Yuzuko Hosoya <hosoya.yuzuko@lab.ntt.co.jp>
Reviewed-by: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Discussion: https://postgr.es/m/00e601d4ca86$932b8bc0$b982a340$@lab.ntt.co.jp
This portion of the code got forgotten in 7cce159 which has introduced a
new routine to build this node, and this finishes the unification of the
places where IndexInfo is initialized.
Author: Michael Paquier
Discussion: https://postgr.es/m/20190801041322.GA3435@paquier.xyz
In 5f32b29c18 I changed the creation of HashState.hashkeys to
actually use HashState as the parent (instead of HashJoinState, which
was incorrect, as they were executed below HashState), to fix the
problem of hashkeys expressions otherwise relying on slot types
appropriate for HashJoinState, rather than HashState as would be
correct. That reliance was only introduced in 12, which is why it
previously worked to use HashJoinState as the parent (although I'd be
unsurprised if there were problematic cases).
Unfortunately that's not a sufficient solution, because before this
commit, the to-be-hashed expressions referenced inner/outer as
appropriate for the HashJoin, not Hash. That didn't have obvious bad
consequences, because the slots containing the tuples were put into
ecxt_innertuple when hashing a tuple for HashState (even though Hash
doesn't have an inner plan).
There are less common cases where this can cause visible problems
however (rather than just confusion when inspecting such executor
trees). E.g. "ERROR: bogus varno: 65000", when explaining queries
containing a HashJoin where the subsidiary Hash node's hash keys
reference a subplan. While normally hashkeys aren't displayed by
EXPLAIN, if one of those expressions references a subplan, that
subplan may be printed as part of the Hash node - which then failed
because an inner plan was referenced, and Hash doesn't have that.
It seems quite possible that there's other broken cases, too.
Fix the problem by properly splitting the expression for the HashJoin
and Hash nodes at plan time, and have them reference the proper
subsidiary node. While other workarounds are possible, fixing this
correctly seems easy enough. It was a pretty ugly hack to have
ExecInitHashJoin put the expression into the already initialized
HashState, in the first place.
I decided to not just split inner/outer hashkeys inside
make_hashjoin(), but also to separate out hashoperators and
hashcollations at plan time. Otherwise we would have ended up having
two very similar loops, one at plan time and the other during executor
startup. The work seems to more appropriately belong to plan time,
anyway.
Reported-By: Nikita Glukhov, Alexander Korotkov
Author: Andres Freund
Reviewed-By: Tom Lane, in an earlier version
Discussion: https://postgr.es/m/CAPpHfdvGVegF_TKKRiBrSmatJL2dR9uwFCuR+teQ_8tEXU8mxg@mail.gmail.com
Backpatch: 12-
This allows simplification of the plan tree in some common usage
patterns: we can get rid of a join to the function RTE.
In principle we could pull up any immutable expression, but restricting
it to Consts avoids the risk that multiple evaluations of the expression
might cost more than we can save. (Possibly this could be improved in
future --- but we've more or less promised people that putting a function
in FROM guarantees single evaluation, so we'd have to tread carefully.)
To do this, we need to rearrange when eval_const_expressions()
happens for expressions in function RTEs. I moved it to
inline_set_returning_functions(), which already has to iterate over
every function RTE, and in consequence renamed that function to
preprocess_function_rtes(). A useful consequence is that
inline_set_returning_function() no longer has to do this for itself,
simplifying that code.
In passing, break out pull_up_simple_subquery's code that knows where
everything that needs pullup_replace_vars() processing is, so that
the new pull_up_constant_function() routine can share it. We'd
gotten away with one-and-a-half copies of that code so far, since
pull_up_simple_values() could assume that a lot of cases didn't apply
to it --- but I don't think pull_up_constant_function() can make any
simplifying assumptions. Might as well make pull_up_simple_values()
use it too.
(Possibly this refactoring should go further: maybe we could share
some of the code to fill in the pullup_replace_vars_context struct?
For now, I left it that the callers fill that completely.)
Note: the one existing test case that this patch changes has to be
changed because inlining its function RTEs would destroy the point
of the test, namely to check join order.
Alexander Kuzmenkov and Aleksandr Parfenov, reviewed by
Antonin Houska and Anastasia Lubennikova, and whacked around
some more by me
Discussion: https://postgr.es/m/402356c32eeb93d4fed01f66d6c7fe2d@postgrespro.ru
Add sort support for inet, including support for abbreviated keys.
Testing has shown that this reduces the time taken to sort medium to
large inet/cidr inputs by ~50-60% in realistic cases.
Author: Brandur Leach
Reviewed-By: Peter Geoghegan, Edmund Horner
Discussion: https://postgr.es/m/CABR_9B-PQ8o2MZNJ88wo6r-NxW2EFG70M96Wmcgf99G6HUQ3sw@mail.gmail.com
Commit a1c1af2a1 added logic in the deadlock checker to handle lock
grouping, but it was very poorly tested, as evidenced by the bug
fixed in 3420851a2. Add a test case that exercises that a bit better
(and catches the bug --- if you revert 3420851a2, this will hang).
Since it's pretty hard to get parallel workers to take exclusive
regular locks that their parents don't already have, this test operates
by creating a deadlock among advisory locks taken in parallel workers.
To make that happen, we must override the parallel-safety labeling of
the advisory-lock functions, which we do by putting them in mislabeled,
non-inlinable wrapper functions.
We also have to remove the redundant PreventAdvisoryLocksInParallelMode
checks in lockfuncs.c. That seems fine though; if some user accidentally
does what this test is intentionally doing, not much harm will ensue.
(If there are any remaining bugs that are reachable that way, they're
probably reachable in other ways too.)
Discussion: https://postgr.es/m/3243.1564437314@sss.pgh.pa.us
These were introduced by pgindent due to fixe to broken
indentation (c.f. 8255c7a5ee). Previously the mis-indentation of
function prototypes was creatively used to reduce indentation in a few
places.
As that formatting only exists in master and REL_12_STABLE, it seems
better to fix it in both, rather than having some odd indentation in
v12 that somebody might copy for future patches or such.
Author: Andres Freund
Discussion: https://postgr.es/m/20190728013754.jwcbe5nfyt3533vx@alap3.anarazel.de
Backpatch: 12-
The rd_amcache allows an index AM to cache arbitrary information in a
relcache entry. This commit moves the cleanup of rd_amcache so that it
can also be used by table AMs. Nothing takes advantage of that yet, but
I'm sure it'll come handy for anyone writing new table AMs.
Backpatch to v12, where table AM interface was introduced.
Reviewed-by: Julien Rouhaud
When performing ANALYZE on inheritance trees, we collect two samples for
each relation - one for the relation alone, and one for the inheritance
subtree (relation and its child relations). And then we build statistics
on each sample, so for each relation we get two sets of statistics.
For regular (per-column) statistics this works fine, because the catalog
includes a flag differentiating statistics built from those two samples.
But we don't have such flag in the extended statistics catalogs, and we
ended up updating the same row twice, triggering this error:
ERROR: tuple already updated by self
The simplest solution is to disable extended statistics on inheritance
trees, which is what this commit is doing. In the future we may need to
do something similar to per-column statistics, but that requires adding a
flag to the catalog - and that's not backpatchable. Moreover, the current
selectivity estimation code only works with individual relations, so
building statistics on inheritance trees would be pointless anyway.
Author: Tomas Vondra
Backpatch-to: 10-
Discussion: https://postgr.es/m/20190618231233.GA27470@telsasoft.com
Reported-by: Justin Pryzby
A "break" statement erroneously left behind by commit a1c1af2a1
caused TopoSort to do the wrong thing if a lock's wait list
contained multiple members of the same locking group.
Because parallel workers don't normally need any locks not already
taken by their leader, this is very hard --- maybe impossible ---
to hit in production. Still, if it did happen, the queries involved
in an otherwise-resolvable deadlock would block until canceled.
In addition to removing the bogus "break", add an Assert showing
that the conflicting uses of the beforeConstraints[] array (for both
counts and flags) don't overlap, and add some commentary explaining
why not; because it's not obvious without explanation, IMHO.
Original report and patch from Rui Hai Jiang; additional assert
and commentary by me. Back-patch to 9.6 where the bug came in.
Discussion: https://postgr.es/m/CAEri+mLd3bpHLyW+a9pSe1y=aEkeuJpwBSwvo-+m4n7-ceRmXw@mail.gmail.com
When copying the definition of an index rebuilt concurrently for the new
entry, the index information was taken directly from the old index using
the relation cache. In this case, predicates and expressions have
some post-processing to prepare things for the planner, which loses some
information including the collations added in any of them.
This inconsistency can cause issues when attempting for example a table
rewrite, and makes the new indexes rebuilt concurrently inconsistent
with the old entries.
In order to fix the problem, fetch expressions and predicates directly
from the catalog of the old entry, and fill in IndexInfo for the new
index with that. This makes the process more consistent with
DefineIndex(), and the code is refactored with the addition of a routine
to create an IndexInfo node.
Reported-by: Manuel Rigger
Author: Michael Paquier
Discussion: https://postgr.es/m/CA+u7OA5Hp0ra235F3czPom_FyAd-3+XwSJmX95r1+sRPOJc9VQ@mail.gmail.com
Backpatch-through: 12
Early previews of LLVM 9 reveal that our Min() macro causes compiler
errors in LLVM headers reached by the #include directives in
llvmjit_inline.cpp. Let's just undefine it. Per buildfarm animal
seawasp. Back-patch to 11.
Reviewed-by: Fabien Coelho, Tom Lane
Discussion: https://postgr.es/m/20190606173216.GA6306%40alvherre.pgsql
pg_timezone_names() tries to avoid showing the "Factory" zone in
the view, mainly because that has traditionally had a very long
"abbreviation" such as "Local time zone must be set--see zic manual page",
so that showing it messes up psql's formatting of the whole view.
Since tzdb version 2016g, IANA instead uses the abbreviation "-00",
which is sane enough that there's no reason to discriminate against it.
On the other hand, it emerges that FreeBSD and possibly other packagers
are so wedded to backwards compatibility that they hack the IANA data
to keep the old spelling --- and not just that old spelling, but even
older spellings that IANA used back in the stone age. This caused the
filter logic to fail to suppress "Factory" at all on such platforms,
though the formatting problem is definitely real in that case.
To solve both problems, get rid of the hard-wired assumption about
exactly what Factory's abbreviation is, and instead reject abbreviations
exceeding 31 characters. This will allow Factory to appear in the view
if and only if it's using the modern abbreviation.
In passing, simplify the code we add to zic.c to support "zic -P"
to remove its now-obsolete hacks to not print the Factory zone's
abbreviation. Unlike pg_timezone_names(), there's no reason for
that code to support old/nonstandard timezone data.
Since we generally prefer to keep timezone-related behavior the
same in all branches, and since this is arguably a bug fix,
back-patch to all supported branches.
Discussion: https://postgr.es/m/3961.1564086915@sss.pgh.pa.us
Money values exceeding about 18 digits (depending on lc_monetary)
could be inaccurately converted to numeric, due to select_div_scale()
deciding it didn't need to compute any fractional digits. Force
its hand by setting the dscale of one division input to equal the
number of fractional digits we need.
In passing, rearrange the logic to not do useless work in locales
where money values are considered integral.
Per bug #15925 from Slawomir Chodnicki. Back-patch to all supported
branches.
Discussion: https://postgr.es/m/15925-da9953e2674bb5c8@postgresql.org
Since 15d8f8312 we assert that - and since 7ef04e4d2c, 4da597edf1
rely on - the slot type for an expression's
ecxt_{outer,inner,scan}tuple not changing, unless explicitly flagged
as such. That allows to either skip deforming (for a virtual tuple
slot) or optimize the code for JIT accelerated deforming
appropriately (for other known slot types).
This assumption was sometimes violated for grouping sets, when
nodeAgg.c internally uses tuplesorts, and the child node doesn't
return a TTSOpsMinimalTuple type slot. Detect that case, and flag that
the outer slot might not be "fixed".
It's probably worthwhile to optimize this further in the future, and
more granularly determine whether the slot is fixed. As we already
instantiate per-phase transition and equal expressions, we could
cheaply set the slot type appropriately for each phase. But that's a
separate change from this bugfix.
This commit does include a very minor optimization by avoiding to
create a slot for handling tuplesorts, if no such sorts are
performed. Previously we created that slot unnecessarily in the common
case of computing all grouping sets via hashing. The code looked too
confusing without that, as the conditions for needing a sort slot and
flagging that the slot type isn't fixed, are the same.
Reported-By: Ashutosh Sharma
Author: Andres Freund
Discussion: https://postgr.es/m/CAE9k0PmNaMD2oHTEAhRyxnxpaDaYkuBYkLa1dpOpn=RS0iS2AQ@mail.gmail.com
Backpatch: 12-, where the bug was introduced in 15d8f8312
libpq failed to ignore Windows-style newlines in connection service files.
This normally wasn't a problem on Windows itself, because fgets() would
convert \r\n to just \n. But if libpq were running inside a program that
changes the default fopen mode to binary, it would see the \r's and think
they were data. In any case, it's project policy to ignore \r in text
files unconditionally, because people sometimes try to use files with
DOS-style newlines on Unix machines, where the C library won't hide that
from us.
Hence, adjust parseServiceFile() to ignore \r as well as \n at the end of
the line. In HEAD, go a little further and make it ignore all trailing
whitespace, to match what it's always done with leading whitespace.
In HEAD, also run around and fix up everyplace where we have
newline-chomping code to make all those places look consistent and
uniformly drop \r. It is not clear whether any of those changes are
fixing live bugs. Most of the non-cosmetic changes are in places that
are reading popen output, and the jury is still out as to whether popen
on Windows can return \r\n. (The Windows-specific code in pipe_read_line
seems to think so, but our lack of support for this elsewhere suggests
maybe it's not a problem in practice.) Hence, I desisted from applying
those changes to back branches, except in run_ssl_passphrase_command()
which is new enough and little-tested enough that we'd probably not have
heard about any problems there.
Tom Lane and Michael Paquier, per bug #15827 from Jorge Gustavo Rocha.
Back-patch the parseServiceFile() change to all supported branches,
and the run_ssl_passphrase_command() change to v11 where that was added.
Discussion: https://postgr.es/m/15827-e6ba53a3a7ed543c@postgresql.org
After 277cb78983 ON CONFLICT ... SET ... RETURNING failed with
ERROR: virtual tuple table slot does not have system attributes
when taking the update path, as the slot used to insert into the
table (and then process RETURNING) was defined to be a virtual slot in
that commit. Virtual slots don't support system columns except for
tableoid and ctid, as the other system columns are AM dependent.
Fix that by using a slot of the table's type. Add tests for system
column accesses in ON CONFLICT ... RETURNING.
Reported-By: Roby, bisected to the relevant commit by Jeff Janes
Author: Andres Freund
Discussion: https://postgr.es/m/73436355-6432-49B1-92ED-1FE4F7E7E100@finefun.com.au
Backpatch: 12-, where the bug was introduced in 277cb78983
Otherwise, after a deleted page gets even older, it becomes unrecyclable
again. B-tree has the same problem, and has had since time immemorial,
but let's at least fix this in GiST, where this is new.
Backpatch to v12, where GiST page deletion was introduced.
Reviewed-by: Andrey Borodin
Discussion: https://www.postgresql.org/message-id/835A15A5-F1B4-4446-A711-BF48357EB602%40yandex-team.ru
The explicit check in gistScanPage() isn't currently really necessary, as
a deleted page is always empty, so the loop would fall through without
doing anything, anyway. But it's a marginal optimization, and it gives a
nice place to attach a comment to explain how it works.
Backpatch to v12, where GiST page deletion was introduced.
Reviewed-by: Andrey Borodin
Discussion: https://www.postgresql.org/message-id/835A15A5-F1B4-4446-A711-BF48357EB602%40yandex-team.ru
If the user creates a deferred constraint in a partition, and in a
transaction they cause the constraint's trigger execution to be deferred
until commit time *and* drop the constraint, then when commit time comes
the queued trigger will fail to run because the trigger object will have
been dropped.
This is explained because when a constraint gets dropped in a
partitioned table, the recursion to drop the ones in partitions is done
by the dependency mechanism, not by ALTER TABLE traversing the recursion
tree as in all other cases. In the non-partitioned case, this problem
is avoided by checking that the table is not "in use" by alter-table;
other alter-table subcommands that recurse to partitions do that check
for each partition. But the dependency mechanism doesn't have a way to
do that. Fix the problem by applying the same check to all partitions
during ALTER TABLE's "prep" phase, which correctly raises the necessary
error.
Reported-by: Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>
Discussion: https://postgr.es/m/CAKcux6nZiO9-eEpr1ZD84bT1mBoVmeZkfont8iSpcmYrjhGWgA@mail.gmail.com
The logic in ATExecDropColumn that rejects dropping partition key
columns is quite an inadequate defense, because it doesn't execute
in cases where a column needs to be dropped due to cascade from
something that only the column, not the whole partitioned table,
depends on. That leaves us with a badly broken partitioned table;
even an attempt to load its relcache entry will fail.
We really need to have explicit pg_depend entries that show that the
column can't be dropped without dropping the whole table. Hence,
add those entries. In v12 and HEAD, bump catversion to ensure that
partitioned tables will have such entries. We can't do that in
released branches of course, so in v10 and v11 this patch affords
protection only to partitioned tables created after the patch is
installed. Given the lack of field complaints (this bug was found
by fuzz-testing not by end users), that's probably good enough.
In passing, fix ATExecDropColumn and ATPrepAlterColumnType
messages to be more specific about which partition key column
they're complaining about.
Per report from Manuel Rigger. Back-patch to v10 where partitioned
tables were added.
Discussion: https://postgr.es/m/CA+u7OA4JKCPFrdrAbOs7XBiCyD61XJxeNav4LefkSmBLQ-Vobg@mail.gmail.com
Discussion: https://postgr.es/m/31920.1562526703@sss.pgh.pa.us
When we already know the length that we're going to append, then it
makes sense to use appendBinaryStringInfo instead of
appendStringInfoString so that the append can be performed with a simple
memcpy() using a known length rather than having to first perform a
strlen() call to obtain the length.
Discussion: https://postgr.es/m/CAKJS1f8+FRAM1s5+mAa3isajeEoAaicJ=4e0WzrH3tAusbbiMQ@mail.gmail.com
Some code could get confused when certain catalog state involving both
identity and serial sequences was present, perhaps during an attempt
to upgrade the latter to the former. Specifically, dropping the
default of a serial column maintains the ownership of the sequence by
the column, and so it would then be possible to afterwards make the
column an identity column that would now own two sequences. This
causes the code that looks up the identity sequence to error out,
making the new identity column inoperable until the ownership of the
previous sequence is released.
To fix this, make the identity sequence lookup only consider sequences
with the appropriate dependency type for an identity sequence, so it
only ever finds one (unless something else is broken). In the above
example, the old serial sequence would then be ignored. Reorganize
the various owned-sequence-lookup functions a bit to make this
clearer.
Reported-by: Laurenz Albe <laurenz.albe@cybertec.at>
Discussion: https://www.postgresql.org/message-id/flat/470c54fc8590be4de0f41b0d295fd6390d5e8a6c.camel@cybertec.at
In nodeAppend.c and nodeMergeAppend.c there were some foreach loops which
looped over the list of subplans and only performed any work if the
subplan index was found in a Bitmapset. With the old linked list
implementation of List, this form made sense as accessing the Nth list
element was O(N). However, thanks to 1cff1b95a we now have array-based
lists, so accessing the Nth element has become O(1).
Here we make the most of the O(1) lookups and just loop over the set
members of the Bitmapset with bms_next_member(). This performs slightly
better when a small number of the list items are in the Bitmapset. Micro
benchmarks show that when the Bitmapset contains all or most of the list
items then the new code is ever so slightly slower. In practice, the cost
is so small that it's drowned out by various other things such as locking
the relations belonging to each subplan, etc.
The primary goal here is to leave better code examples around which benefit
better from the new list implementation.
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/CAKJS1f8ZcsLVgkF4wOfRyMYTcPgLFiUAOedFC+U2vK_aFZk-BA@mail.gmail.com
3373c7155 changed how we determine EquivalenceClasses for relations and
added an Assert to ensure all relations mentioned in each EC's ec_relids
was a RELOPT_BASEREL. However, the join removal code may remove a LEFT
JOIN and since it does not clean up EC members belonging to the removed
relations it can leave RELOPT_DEADREL rels in ec_relids.
Fix this by adjusting the Assert to allow RELOPT_DEADREL rels too.
Reported-by: sqlsmith via Andreas Seltenreich
Discussion: https://postgr.es/m/87y30r8sls.fsf@ansel.ydns.eu
Coverity complained about this code, apparently because it uses a local
array of size FUNC_MAX_ARGS without a guard that the input argument list
is no longer than that. (Not sure why it complained today, since this
code's been the same for a long time; possibly it re-analyzed everything
the List API change touched?)
Rather than add a guard, though, let's just get rid of the local array
altogether. It was only there to avoid list_nth() calls, and those are
no longer expensive.
Previously in order to determine which ECs a relation had members in, we
had to loop over all ECs stored in PlannerInfo's eq_classes and check if
ec_relids mentioned the relation. For the most part, this was fine, as
generally, unless queries were fairly complex, the overhead of performing
the lookup would have not been that significant. However, when queries
contained large numbers of joins and ECs, the overhead to find the set of
classes matching a given set of relations could become a significant
portion of the overall planning effort.
Here we allow a much more efficient method to access the ECs which match a
given relation or set of relations. A new Bitmapset field in RelOptInfo
now exists to store the indexes into PlannerInfo's eq_classes list which
each relation is mentioned in. This allows very fast lookups to find all
ECs belonging to a single relation. When we need to lookup ECs belonging
to a given pair of relations, we can simply bitwise-AND the Bitmapsets from
each relation and use the result to perform the lookup.
We also take the opportunity to write a new implementation of
generate_join_implied_equalities which makes use of the new indexes.
generate_join_implied_equalities_for_ecs must remain as is as it can be
given a custom list of ECs, which we can't easily determine the indexes of.
This was originally intended to fix the performance penalty of looking up
foreign keys matching a join condition which was introduced by 100340e2d.
However, we're speeding up much more than just that here.
Author: David Rowley, Tom Lane
Reviewed-by: Tom Lane, Tomas Vondra
Discussion: https://postgr.es/m/6970.1545327857@sss.pgh.pa.us
The current extended statistics code was a bit confused which collation
to use. When building the statistics, the collations defined as default
for the data types were used (since commit 5e0928005). The MCV code was
however using the column collations for MCV serialization, and then
DEFAULT_COLLATION_OID when computing estimates. So overall the code was
using all three possible options, inconsistently.
This uses the column colation everywhere - this makes it consistent with
what 5e0928005 did for regular stats. We however do not track the
collations in a catalog, because we can derive them from column-level
information. This may need to change in the future, e.g. after allowing
statistics on expressions.
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
Backpatch-to: 12
The examine_opclause_expression function needs to return information on
which side of the operator we found the Var, but the variable was called
"isgt" which is rather misleading (it assumes the operator is either
less-than or greater-than, but it may be equality or something else).
Other places in the planner use a variable called "varonleft" for this
purpose, so just adopt the same convention here.
The code also assumed we don't care about this flag for equality, as
(Var = Const) and (Const = Var) should be the same thing. But that does
not work for cross-type operators, in which case we need to pass the
parameters to the procedure in the right order. So just use the same
code for all types of expressions.
This means we don't need to care about the selectivity estimation
function anymore, at least not in this code. We should only get the
supported cases here (thanks to statext_is_compatible_clause).
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
Backpatch-to: 12
The values 'infinity' and '-infinity' are a part of the DATE type
itself, so a bound of the date 'infinity' is not the same as an
unbounded/infinite range. However, it is still wrong to try to
canonicalize such values, because adding or subtracting one has no
effect. Fix by treating 'infinity' and '-infinity' the same as
unbounded ranges for the purposes of canonicalization (but not other
purposes).
Backpatch to all versions because it is inconsistent with the
documented behavior. Note that this could be an incompatibility for
applications relying on the behavior contrary to the documentation.
Author: Laurenz Albe
Reviewed-by: Thomas Munro
Discussion: https://postgr.es/m/77f24ea19ab802bc9bc60ddbb8977ee2d646aec1.camel%40cybertec.at
Backpatch-through: 9.4
Commit 857f9c36cd, which taught nbtree VACUUM to avoid unnecessary
index scans, bumped the nbtree version number from 2 to 3, while adding
the ability for nbtree indexes to be upgraded on-the-fly. Various
assertions that assumed that an nbtree index was always on version 2 had
to be changed to accept any supported version (version 2 or 3 on
Postgres 11).
However, a few assertions were missed in the initial commit, all of
which were in code paths that cache a local copy of the metapage
metadata, where the index had been expected to be on the current version
(no longer version 2) as a generic sanity check. Rather than simply
update the assertions, follow-up commit 0a64b45152 intentionally made
the metapage caching code update the per-backend cached metadata version
without changing the on-disk version at the same time. This could even
happen when the planner needed to determine the height of a B-Tree for
costing purposes. The assertions only fail on Postgres v12 when
upgrading from v10, because they were adjusted to use the authoritative
shared memory metapage by v12's commit dd299df8.
To fix, remove the cache-only upgrade mechanism entirely, and update the
assertions themselves to accept any supported version (go back to using
the cached version in v12). The fix is almost a full revert of commit
0a64b45152 on the v11 branch.
VACUUM only considers the authoritative metapage, and never bothers with
a locally cached version, whereas everywhere else isn't interested in
the metapage fields that were added by commit 857f9c36cd. It seems
unlikely that this bug has affected any user on v11.
Reported-By: Christoph Berg
Bug: #15896
Discussion: https://postgr.es/m/15896-5b25e260fdb0b081%40postgresql.org
Backpatch: 11-, where VACUUM was taught to avoid unnecessary index scans.
Now that commit fec0778c8 drew a clear line between public and private
fields in SPITupleTable, it seems pretty silly that the count of valid
tuples isn't on the public side of that line. The reason why not was
that there wasn't such a count. For reasons lost in the mists of time,
spi.c preferred to keep a count of remaining free entries in the array.
But that seems pretty pointless: it's unlike the way we handle similar
code everywhere else, and it involves extra subtractions that surely
outweigh having to do a comparison rather than test-for-zero to check
for array-full.
Hence, rearrange so that this code does the expansible array logic
the same as everywhere else, with a count of valid entries alongside
the allocated array length. And document the count as public.
I looked for core-code callers where it would make sense to start
relying on tuptable->numvals rather than the separate SPI_processed
variable. Right now there don't seem to be places where it'd be
a win to do so without more code restructuring than I care to
undertake today. In principle, though, having SPITupleTables be
fully self-contained should be helpful down the line.
Discussion: https://postgr.es/m/16852.1563395722@sss.pgh.pa.us
When evaluating clauses on a multivariate MCV list, we build a bitmap
tracking how the clauses match each item of the MCV list. When updating
the bitmap we need to consider the current value (tracking how the item
matches preceding clauses), match for the current clause and whether the
clauses are connected by AND or OR.
Until now the logic was copied on every place updating the bitmap, which
was not quite readable. So just move it to a separate function and call
it where needed.
Backpatch to 12, where the code was introduced. While not a bugfix, this
should make maintenance and future backpatches easier.
Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
There were two issues in how the extended statistics handled NULL values
in opclauses. Firstly, the code was oblivious to the possibility that
Const may be NULL (constisnull=true) in which case the constvalue is
undefined. We need to treat this as a mismatch, and not call the proc.
Secondly, the MCV item itself may contain NULL values too - the code
already did check that, and updated the match bitmap accordingly, but
failed to ensure we won't call the operator procedure anyway. It did
work for AND-clauses, because in that case false in the bitmap stops
evaluation of further clauses. But for OR-clauses ir was not easy to
get incorrect estimates or even trigger a crash.
This fixes both issues by extending the existing check so that it looks
at constisnull too, and making sure it skips calling the procedure.
Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
We expect opclauses to have exactly one Var and one Const, but the code
was checking the Const by calling is_pseudo_constant_clause() which is
incorrect - we need a proper constant.
Fixed by using plain IsA(x,Const) to check type of the node. We need to
do these checks in two places, so move it into a separate function that
can be called in both places.
Reported by Andreas Seltenreich, based on crash reported by sqlsmith.
Backpatch to v12, where this code was introduced.
Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
Backpatch-to: 12
The TYPECACHE_GT_OPR is not needed (it used to be in older version of
the MCV code), but the compiler failed to detect this as the result was
used in a fmgr_info() call, populating a FmgrInfo entry.
Backpatch to v12, where this code was introduced.
Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
Backpatch-to: 12
Formerly, lcons was about the same speed as lappend, but with the new
List implementation, that's not so; with a long List, data movement
imposes an O(N) cost on lcons and list_delete_first, but not lappend.
Hence, invent list_delete_last with semantics parallel to
list_delete_first (but O(1) cost), and change various places to use
lappend and list_delete_last where this can be done without much
violence to the code logic.
There are quite a few places that construct result lists using lcons not
lappend. Some have semantic rationales for that; I added comments about
it to a couple that didn't have them already. In many such places though,
I think the coding is that way only because back in the dark ages lcons
was faster than lappend. Hence, switch to lappend where this can be done
without causing semantic changes.
In ExecInitExprRec(), this results in aggregates and window functions that
are in the same plan node being executed in a different order than before.
Generally, the executions of such functions ought to be independent of
each other, so this shouldn't result in visibly different query results.
But if you push it, as one regression test case does, you can show that
the order is different. The new order seems saner; it's closer to
the order of the functions in the query text. And we never documented
or promised anything about this, anyway.
Also, in gistfinishsplit(), don't bother building a reverse-order list;
it's easy now to iterate backwards through the original list.
It'd be possible to go further towards removing uses of lcons and
list_delete_first, but it'd require more extensive logic changes,
and I'm not convinced it's worth it. Most of the remaining uses
deal with queues that probably never get long enough to be worth
sweating over. (Actually, I doubt that any of the changes in this
patch will have measurable performance effects either. But better
to have good examples than bad ones in the code base.)
Patch by me, thanks to David Rowley and Daniel Gustafsson for review.
Discussion: https://postgr.es/m/21272.1563318411@sss.pgh.pa.us
Potential future SMGR implementations may not want to create
tablespace directories when creating an SMGR relation. Move that
logic to mdcreate(). Move the initialization of md-specific
data structures from smgropen() to a new callback mdopen().
Author: Thomas Munro
Reviewed-by: Shawn Debnath (as part of an earlier patch set)
Discussion: https://postgr.es/m/CA%2BhUKG%2BOZqOiOuDm5tC5DyQZtJ3FH4%2BFSVMqtdC4P1atpJ%2Bqhg%40mail.gmail.com
This should lappend the OIDs, not lcons them; the existing code produced
a list in reversed order. This is harmless for single-key FKs or FKs
where all the key columns are of the same type, which probably explains
how it went unnoticed. But if those conditions are not met,
ATAddForeignKeyConstraint would make the wrong decision about whether an
existing FK needs to be revalidated. I think it would almost always err
in the safe direction by revalidating a constraint that didn't need it.
You could imagine scenarios where the pfeqop check was fooled by
swapping the types of two FK columns in one ALTER TABLE, but that case
would probably be rejected by other tests, so it might be impossible to
get to the worst-case scenario where an FK should be revalidated and
isn't. (And even then, it's likely to be fine, unless there are weird
inconsistencies in the equality behavior of the replacement types.)
However, this is a performance bug at least.
Noted while poking around to see whether lcons calls could be converted
to lappend.
This bug is old, dating to commit cb3a7c2b9, so back-patch to all
supported branches.
It seems worth getting rid of these functions because they require the
caller to retain a ListCell pointer into a List that it's modifying,
which is a dangerous practice with the new List implementation.
(The only other List-modifying function that takes a ListCell pointer
as input is list_delete_cell, which nowadays is preferentially used
via the constrained API foreach_delete_current.)
There was only one remaining caller of these functions after commit
2f5b8eb5a, and that was some fairly ugly GEQO code that can be much
more clearly expressed using a list-index variable and list_insert_nth.
Hence, rewrite that code, and remove the functions.
Discussion: https://postgr.es/m/26193.1563228600@sss.pgh.pa.us
heap.c and relcache.c contained nearly identical copies of logic
to insert OIDs into an OID list while preserving the list's OID
ordering (and rejecting duplicates, in one case but not the other).
The comments argue that this is faster than qsort for small numbers
of OIDs, which is at best unproven, and seems even less likely to be
true now that lappend_cell_oid has to move data around. In any case
it's ugly and hard-to-follow code, and if we do have a lot of OIDs
to consider, it's O(N^2).
Hence, replace with simply lappend'ing OIDs to a List, then list_sort
the completed List, then remove adjacent duplicates if necessary.
This is demonstrably O(N log N) and it's much simpler for the
callers. It's possible that this would be somewhat inefficient
if there were a very large number of duplicates, but that seems
unlikely in the existing usage.
This adds list_deduplicate_oid and list_oid_cmp infrastructure
to list.c. I didn't bother with equivalent functionality for
integer or pointer Lists, but such could always be added later
if we find a use for it.
Discussion: https://postgr.es/m/26193.1563228600@sss.pgh.pa.us
In the wake of commit 1cff1b95a, the obvious way to sort a List
is to apply qsort() directly to the array of ListCells. list_qsort
was building an intermediate array of pointers-to-ListCells, which
we no longer need, but getting rid of it forces an API change:
the comparator functions need to do one less level of indirection.
Since we're having to touch the callers anyway, let's do two additional
changes: sort the given list in-place rather than making a copy (as
none of the existing callers have any use for the copying behavior),
and rename list_qsort to list_sort. It was argued that the old name
exposes more about the implementation than it should, which I find
pretty questionable, but a better reason to rename it is to be sure
we get the attention of any external callers about the need to fix
their comparator functions.
While we're at it, change four existing callers of qsort() to use
list_sort instead; previously, they all had local reinventions
of list_qsort, ie build-an-array-from-a-List-and-qsort-it.
(There are some other places where changing to list_sort perhaps
would be worthwhile, but they're less obviously wins.)
Discussion: https://postgr.es/m/29361.1563220190@sss.pgh.pa.us
This is numbered take 7, and addresses a set of issues around:
- Fixes for typos and incorrect reference names.
- Removal of unneeded comments.
- Removal of unreferenced functions and structures.
- Fixes regarding variable name consistency.
Author: Alexander Lakhin
Discussion: https://postgr.es/m/10bfd4ac-3e7c-40ab-2b2e-355ed15495e8@gmail.com
The logic just added by commit e3899ffd falls back on a 50:50 page split
in the event of a new item that's just to the right of our provisional
"many duplicates" split point. Fix a comment that incorrectly claimed
that the new item had to be just to the left of our provisional split
point.
Backpatch: 12-, just like commit e3899ffd.
Specific ever-decreasing insertion patterns could cause successive
unbalanced nbtree page splits. Problem cases involve a large group of
duplicates to the left, and ever-decreasing insertions to the right.
To fix, detect the situation by considering the newitem offset before
performing a split using nbtsplitloc.c's "many duplicates" strategy. If
the new item was inserted just to the right of our provisional "many
duplicates" split point, infer ever-decreasing insertions and fall back
on a 50:50 (space delta optimal) split. This seems to barely affect
cases that already had acceptable space utilization.
An alternative fix also seems possible. Instead of changing
nbtsplitloc.c split choice logic, we could instead teach _bt_truncate()
to generate a new value for new high keys by interpolating from the
lastleft and firstright key values. That would certainly be a more
elegant fix, but it isn't suitable for backpatching.
Discussion: https://postgr.es/m/CAH2-WznCNvhZpxa__GqAa1fgQ9uYdVc=_apArkW2nc-K3O7_NA@mail.gmail.com
Backpatch: 12-, where the nbtree page split enhancements were introduced.
Originally, Postgres Lists were a more or less exact reimplementation of
Lisp lists, which consist of chains of separately-allocated cons cells,
each having a value and a next-cell link. We'd hacked that once before
(commit d0b4399d8) to add a separate List header, but the data was still
in cons cells. That makes some operations -- notably list_nth() -- O(N),
and it's bulky because of the next-cell pointers and per-cell palloc
overhead, and it's very cache-unfriendly if the cons cells end up
scattered around rather than being adjacent.
In this rewrite, we still have List headers, but the data is in a
resizable array of values, with no next-cell links. Now we need at
most two palloc's per List, and often only one, since we can allocate
some values in the same palloc call as the List header. (Of course,
extending an existing List may require repalloc's to enlarge the array.
But this involves just O(log N) allocations not O(N).)
Of course this is not without downsides. The key difficulty is that
addition or deletion of a list entry may now cause other entries to
move, which it did not before.
For example, that breaks foreach() and sister macros, which historically
used a pointer to the current cons-cell as loop state. We can repair
those macros transparently by making their actual loop state be an
integer list index; the exposed "ListCell *" pointer is no longer state
carried across loop iterations, but is just a derived value. (In
practice, modern compilers can optimize things back to having just one
loop state value, at least for simple cases with inline loop bodies.)
In principle, this is a semantics change for cases where the loop body
inserts or deletes list entries ahead of the current loop index; but
I found no such cases in the Postgres code.
The change is not at all transparent for code that doesn't use foreach()
but chases lists "by hand" using lnext(). The largest share of such
code in the backend is in loops that were maintaining "prev" and "next"
variables in addition to the current-cell pointer, in order to delete
list cells efficiently using list_delete_cell(). However, we no longer
need a previous-cell pointer to delete a list cell efficiently. Keeping
a next-cell pointer doesn't work, as explained above, but we can improve
matters by changing such code to use a regular foreach() loop and then
using the new macro foreach_delete_current() to delete the current cell.
(This macro knows how to update the associated foreach loop's state so
that no cells will be missed in the traversal.)
There remains a nontrivial risk of code assuming that a ListCell *
pointer will remain good over an operation that could now move the list
contents. To help catch such errors, list.c can be compiled with a new
define symbol DEBUG_LIST_MEMORY_USAGE that forcibly moves list contents
whenever that could possibly happen. This makes list operations
significantly more expensive so it's not normally turned on (though it
is on by default if USE_VALGRIND is on).
There are two notable API differences from the previous code:
* lnext() now requires the List's header pointer in addition to the
current cell's address.
* list_delete_cell() no longer requires a previous-cell argument.
These changes are somewhat unfortunate, but on the other hand code using
either function needs inspection to see if it is assuming anything
it shouldn't, so it's not all bad.
Programmers should be aware of these significant performance changes:
* list_nth() and related functions are now O(1); so there's no
major access-speed difference between a list and an array.
* Inserting or deleting a list element now takes time proportional to
the distance to the end of the list, due to moving the array elements.
(However, it typically *doesn't* require palloc or pfree, so except in
long lists it's probably still faster than before.) Notably, lcons()
used to be about the same cost as lappend(), but that's no longer true
if the list is long. Code that uses lcons() and list_delete_first()
to maintain a stack might usefully be rewritten to push and pop at the
end of the list rather than the beginning.
* There are now list_insert_nth...() and list_delete_nth...() functions
that add or remove a list cell identified by index. These have the
data-movement penalty explained above, but there's no search penalty.
* list_concat() and variants now copy the second list's data into
storage belonging to the first list, so there is no longer any
sharing of cells between the input lists. The second argument is
now declared "const List *" to reflect that it isn't changed.
This patch just does the minimum needed to get the new implementation
in place and fix bugs exposed by the regression tests. As suggested
by the foregoing, there's a fair amount of followup work remaining to
do.
Also, the ENABLE_LIST_COMPAT macros are finally removed in this
commit. Code using those should have been gone a dozen years ago.
Patch by me; thanks to David Rowley, Jesper Pedersen, and others
for review.
Discussion: https://postgr.es/m/11587.1550975080@sss.pgh.pa.us
In order to be able to work with FullTransactionId values during replay
without increasing the size of the WAL, infer the epoch. In general we
can't do that safely, but during replay we can because we know that
nextFullXid can't advance concurrently.
Prevent frontend code from seeing this new function, due to the above
restriction. Perhaps in future it will be possible to extract the value
entirely from independent WAL records, and then this restriction can be
lifted.
Author: Thomas Munro, based on earlier code from Andres Freund
Discussion: https://postgr.es/m/CA%2BhUKG%2BmLmuDjMi6o1dxkKvGRL56Y2Rz%2BiXAcrZV03G9ZuFQ8Q%40mail.gmail.com
This adds a built-in function to generate UUIDs.
PostgreSQL hasn't had a built-in function to generate a UUID yet,
relying on external modules such as uuid-ossp and pgcrypto to provide
one. Now that we have a strong random number generator built-in, we
can easily provide a version 4 (random) UUID generation function.
This patch takes the existing function gen_random_uuid() from pgcrypto
and makes it a built-in function. The pgcrypto implementation now
internally redirects to the built-in one.
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
Discussion: https://www.postgresql.org/message-id/6a65610c-46fc-2323-6b78-e8086340a325@2ndquadrant.com
Index-based calculation of this operator is exact. So, signature of
gist_bbox_distance() function is changes so that caller is responsible for
setting *recheck flag.
Discussion: https://postgr.es/m/f71ba19d-d989-63b6-f04a-abf02ad9345d%40postgrespro.ru
Author: Nikita Glukhov
Reviewed-by: Tom Lane, Alexander Korotkov
Some of <-> operators between geometric types have their commutators missed.
This commit adds them. The motivation is upcoming kNN support for some of those
operators.
Discussion: https://postgr.es/m/f71ba19d-d989-63b6-f04a-abf02ad9345d%40postgrespro.ru
Author: Nikita Glukhov
Reviewed-by: Tom Lane, Alexander Korotkov
After a process decides not to wait for a condition variable, it can
still consume a signal before it reaches ConditionVariableCancelSleep().
In that case, pass the signal on to another waiter if possible, so that
a signal doesn't go missing when there is another process ready to
receive it.
Author: Thomas Munro
Reviewed-by: Shawn Debnath
Discussion: https://postgr.es/m/CA%2BhUKGLQ_RW%2BXs8znDn36e-%2Bmq2--zrPemBqTQ8eKT-VO1OF4Q%40mail.gmail.com
Peter Geoghegan
Alvaro Herrera
Tom Lane
Amit Kapila
Bruce Momjian
Michael Paquier
Thomas Munro
Peter Eisentraut
Robert Haas
Heikki Linnakangas
Etsuro Fujita
Jeff Davis
Tomas Vondra
Joe Conway
Fujii Masao
Alexander Korotkov
Andres Freund
Andrew Gierth
Noah Misch
David Rowley