If existing CHECK or NOT NULL constraints preclude the presence
of nulls, we need not look to see whether any are present.
Sergei Kornilov, reviewed by Stephen Frost, Ildar Musin, David Rowley,
and by me.
Discussion: http://postgr.es/m/81911511895540@web58j.yandex.ru
Too allow table accesses to be not directly dependent on heap, several
new abstractions are needed. Specifically:
1) Heap scans need to be generalized into table scans. Do this by
introducing TableScanDesc, which will be the "base class" for
individual AMs. This contains the AM independent fields from
HeapScanDesc.
The previous heap_{beginscan,rescan,endscan} et al. have been
replaced with a table_ version.
There's no direct replacement for heap_getnext(), as that returned
a HeapTuple, which is undesirable for a other AMs. Instead there's
table_scan_getnextslot(). But note that heap_getnext() lives on,
it's still used widely to access catalog tables.
This is achieved by new scan_begin, scan_end, scan_rescan,
scan_getnextslot callbacks.
2) The portion of parallel scans that's shared between backends need
to be able to do so without the user doing per-AM work. To achieve
that new parallelscan_{estimate, initialize, reinitialize}
callbacks are introduced, which operate on a new
ParallelTableScanDesc, which again can be subclassed by AMs.
As it is likely that several AMs are going to be block oriented,
block oriented callbacks that can be shared between such AMs are
provided and used by heap. table_block_parallelscan_{estimate,
intiialize, reinitialize} as callbacks, and
table_block_parallelscan_{nextpage, init} for use in AMs. These
operate on a ParallelBlockTableScanDesc.
3) Index scans need to be able to access tables to return a tuple, and
there needs to be state across individual accesses to the heap to
store state like buffers. That's now handled by introducing a
sort-of-scan IndexFetchTable, which again is intended to be
subclassed by individual AMs (for heap IndexFetchHeap).
The relevant callbacks for an AM are index_fetch_{end, begin,
reset} to create the necessary state, and index_fetch_tuple to
retrieve an indexed tuple. Note that index_fetch_tuple
implementations need to be smarter than just blindly fetching the
tuples for AMs that have optimizations similar to heap's HOT - the
currently alive tuple in the update chain needs to be fetched if
appropriate.
Similar to table_scan_getnextslot(), it's undesirable to continue
to return HeapTuples. Thus index_fetch_heap (might want to rename
that later) now accepts a slot as an argument. Core code doesn't
have a lot of call sites performing index scans without going
through the systable_* API (in contrast to loads of heap_getnext
calls and working directly with HeapTuples).
Index scans now store the result of a search in
IndexScanDesc->xs_heaptid, rather than xs_ctup->t_self. As the
target is not generally a HeapTuple anymore that seems cleaner.
To be able to sensible adapt code to use the above, two further
callbacks have been introduced:
a) slot_callbacks returns a TupleTableSlotOps* suitable for creating
slots capable of holding a tuple of the AMs
type. table_slot_callbacks() and table_slot_create() are based
upon that, but have additional logic to deal with views, foreign
tables, etc.
While this change could have been done separately, nearly all the
call sites that needed to be adapted for the rest of this commit
also would have been needed to be adapted for
table_slot_callbacks(), making separation not worthwhile.
b) tuple_satisfies_snapshot checks whether the tuple in a slot is
currently visible according to a snapshot. That's required as a few
places now don't have a buffer + HeapTuple around, but a
slot (which in heap's case internally has that information).
Additionally a few infrastructure changes were needed:
I) SysScanDesc, as used by systable_{beginscan, getnext} et al. now
internally uses a slot to keep track of tuples. While
systable_getnext() still returns HeapTuples, and will so for the
foreseeable future, the index API (see 1) above) now only deals with
slots.
The remainder, and largest part, of this commit is then adjusting all
scans in postgres to use the new APIs.
Author: Andres Freund, Haribabu Kommi, Alvaro Herrera
Discussion:
https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.dehttps://postgr.es/m/20160812231527.GA690404@alvherre.pgsql
... as well as its implementation from backend/access/hash/hashfunc.c to
backend/utils/hash/hashfn.c.
access/hash is the place for the hash index AM, not really appropriate
for generic facilities, which is what hash_any is; having things the old
way meant that anything using hash_any had to include the AM's include
file, pointlessly polluting its namespace with unrelated, unnecessary
cruft.
Also move the HTEqual strategy number to access/stratnum.h from
access/hash.h.
To avoid breaking third-party extension code, add an #include
"utils/hashutils.h" to access/hash.h. (An easily removed line by
committers who enjoy their asbestos suits to protect them from angry
extension authors.)
Discussion: https://postgr.es/m/201901251935.ser5e4h6djt2@alvherre.pgsql
This change makes it possible to specify sub-millisecond delays,
which work well on most modern platforms, though that was not true
when the cost-delay feature was designed.
To support this without breaking existing configuration entries,
improve guc.c to allow floating-point GUCs to have units. Also,
allow "us" (microseconds) as an input/output unit for time-unit GUCs.
(It's not allowed as a base unit, at least not yet.)
Likewise change the autovacuum_vacuum_cost_delay reloption to be
floating-point; this forces a catversion bump because the layout of
StdRdOptions changes.
This patch doesn't in itself change the default values or allowed
ranges for these parameters, and it should not affect the behavior
for any already-allowed setting for them.
Discussion: https://postgr.es/m/1798.1552165479@sss.pgh.pa.us
When the timezone is UTC, timestamptz and timestamp are binary coercible
in both directions. See b8a18ad485 and
c22ecc6562 for the previous attempt in
this problem space. Skip the table rewrite; for now, continue to
needlessly rewrite any index on an affected column.
Reviewed by Simon Riggs and Tom Lane.
Discussion: https://postgr.es/m/20190226061450.GA1665944@rfd.leadboat.com
We still require AccessExclusiveLock on the partition itself, because
otherwise an insert that violates the newly-imposed partition
constraint could be in progress at the same time that we're changing
that constraint; only the lock level on the parent relation is
weakened.
To make this safe, we have to cope with (at least) three separate
problems. First, relevant DDL might commit while we're in the process
of building a PartitionDesc. If so, find_inheritance_children() might
see a new partition while the RELOID system cache still has the old
partition bound cached, and even before invalidation messages have
been queued. To fix that, if we see that the pg_class tuple seems to
be missing or to have a null relpartbound, refetch the value directly
from the table. We can't get the wrong value, because DETACH PARTITION
still requires AccessExclusiveLock throughout; if we ever want to
change that, this will need more thought. In testing, I found it quite
difficult to hit even the null-relpartbound case; the race condition
is extremely tight, but the theoretical risk is there.
Second, successive calls to RelationGetPartitionDesc might not return
the same answer. The query planner will get confused if lookup up the
PartitionDesc for a particular relation does not return a consistent
answer for the entire duration of query planning. Likewise, query
execution will get confused if the same relation seems to have a
different PartitionDesc at different times. Invent a new
PartitionDirectory concept and use it to ensure consistency. This
ensures that a single invocation of either the planner or the executor
sees the same view of the PartitionDesc from beginning to end, but it
does not guarantee that the planner and the executor see the same
view. Since this allows pointers to old PartitionDesc entries to
survive even after a relcache rebuild, also postpone removing the old
PartitionDesc entry until we're certain no one is using it.
For the most part, it seems to be OK for the planner and executor to
have different views of the PartitionDesc, because the executor will
just ignore any concurrently added partitions which were unknown at
plan time; those partitions won't be part of the inheritance
expansion, but invalidation messages will trigger replanning at some
point. Normally, this happens by the time the very next command is
executed, but if the next command acquires no locks and executes a
prepared query, it can manage not to notice until a new transaction is
started. We might want to tighten that up, but it's material for a
separate patch. There would still be a small window where a query
that started just after an ATTACH PARTITION command committed might
fail to notice its results -- but only if the command starts before
the commit has been acknowledged to the user. All in all, the warts
here around serializability seem small enough to be worth accepting
for the considerable advantage of being able to add partitions without
a full table lock.
Although in general the consequences of new partitions showing up
between planning and execution are limited to the query not noticing
the new partitions, run-time partition pruning will get confused in
that case, so that's the third problem that this patch fixes.
Run-time partition pruning assumes that indexes into the PartitionDesc
are stable between planning and execution. So, add code so that if
new partitions are added between plan time and execution time, the
indexes stored in the subplan_map[] and subpart_map[] arrays within
the plan's PartitionedRelPruneInfo get adjusted accordingly. There
does not seem to be a simple way to generalize this scheme to cope
with partitions that are removed, mostly because they could then get
added back again with different bounds, but it works OK for added
partitions.
This code does not try to ensure that every backend participating in
a parallel query sees the same view of the PartitionDesc. That
currently doesn't matter, because we never pass PartitionDesc
indexes between backends. Each backend will ignore the concurrently
added partitions which it notices, and it doesn't matter if different
backends are ignoring different sets of concurrently added partitions.
If in the future that matters, for example because we allow writes in
parallel query and want all participants to do tuple routing to the same
set of partitions, the PartitionDirectory concept could be improved to
share PartitionDescs across backends. There is a draft patch to
serialize and restore PartitionDescs on the thread where this patch
was discussed, which may be a useful place to start.
Patch by me. Thanks to Alvaro Herrera, David Rowley, Simon Riggs,
Amit Langote, and Michael Paquier for discussion, and to Alvaro
Herrera for some review.
Discussion: http://postgr.es/m/CA+Tgmobt2upbSocvvDej3yzokd7AkiT+PvgFH+a9-5VV1oJNSQ@mail.gmail.com
Discussion: http://postgr.es/m/CA+TgmoZE0r9-cyA-aY6f8WFEROaDLLL7Vf81kZ8MtFCkxpeQSw@mail.gmail.com
Discussion: http://postgr.es/m/CA+TgmoY13KQZF-=HNTrt9UYWYx3_oYOQpu9ioNT49jGgiDpUEA@mail.gmail.com
This introduces the concept of table access methods, i.e. CREATE
ACCESS METHOD ... TYPE TABLE and
CREATE TABLE ... USING (storage-engine).
No table access functionality is delegated to table AMs as of this
commit, that'll be done in following commits.
Subsequent commits will incrementally abstract table access
functionality to be routed through table access methods. That change
is too large to be reviewed & committed at once, so it'll be done
incrementally.
Docs will be updated at the end, as adding them incrementally would
likely make them less coherent, and definitely is a lot more work,
without a lot of benefit.
Table access methods are specified similar to index access methods,
i.e. pg_am.amhandler returns, as INTERNAL, a pointer to a struct with
callbacks. In contrast to index AMs that struct needs to live as long
as a backend, typically that's achieved by just returning a pointer to
a constant struct.
Psql's \d+ now displays a table's access method. That can be disabled
with HIDE_TABLEAM=true, which is mainly useful so regression tests can
be run against different AMs. It's quite possible that this behaviour
still needs to be fine tuned.
For now it's not allowed to set a table AM for a partitioned table, as
we've not resolved how partitions would inherit that. Disallowing
allows us to introduce, if we decide that's the way forward, such a
behaviour without a compatibility break.
Catversion bumped, to add the heap table AM and references to it.
Author: Haribabu Kommi, Andres Freund, Alvaro Herrera, Dimitri Golgov and others
Discussion:
https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.dehttps://postgr.es/m/20160812231527.GA690404@alvherre.pgsqlhttps://postgr.es/m/20190107235616.6lur25ph22u5u5av@alap3.anarazel.dehttps://postgr.es/m/20190304234700.w5tmhducs5wxgzls@alap3.anarazel.de
After ff11e7f4b9 Tom's compiler warns about accessing a potentially
uninitialized rInfo. That's not actually possible, but it's
understandable the compiler would get this wrong. NULL initialize too.
Reported-By: Tom Lane
Discussion: https://postgr.es/m/11199.1551285318@sss.pgh.pa.us
In preparation for abstracting table storage, convert trigger.c to
track tuples in slots. Which also happens to make code calling
triggers simpler.
As the calling interface for triggers themselves is not changed in
this patch, HeapTuples still are extracted from the slot at that
time. But that's handled solely inside trigger.c, not visible to
callers. It's quite likely that we'll want to revise the external
trigger interface, but that's a separate large project.
As part of this work the slots used for old/new/return tuples are
moved from EState into ResultRelInfo, as different updated tables
might need different slots. The slots are now also now created
on-demand, which is good both from an efficiency POV, but also makes
the modifying code simpler.
Author: Andres Freund, Amit Khandekar and Ashutosh Bapat
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
After the introduction of tuple table slots all table AMs need to
support returning the table oid of the tuple stored in a slot created
by said AM. It does not make sense to re-implement that in every AM,
therefore move handling of table OIDs into the TupleTableSlot
structure itself. It's possible that we, at a later date, might want
to get rid of HeapTupleData.t_tableOid entirely, but doing so before
the abstractions for table AMs are integrated turns out to be too
hard, so delay that for now.
Similarly, every AM needs to support the concept of a tuple
identifier (tid / item pointer) for its tuples. It's quite possible
that we'll generalize the exact form of a tid at a future point (to
allow for things like index organized tables), but for now many parts
of the code know about tids, so there's not much point in abstracting
tids away. Therefore also move into slot (rather than providing API to
set/get the tid associated with the tuple in a slot).
Once table AM includes insert/updating/deleting tuples, the
responsibility to set the correct tid after such an action will move
into that. After that change, code doing such modifications, should
not have to deal with HeapTuples directly anymore.
Author: Andres Freund, Haribabu Kommi and Ashutosh Bapat
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
Remove some unnecessary, legacy-looking use of the PROCEDURAL keyword
before LANGUAGE. We mostly don't use this anymore, so some of these
look a bit old.
There is still some use in pg_dump, which is harder to remove because
it's baked into the archive format, so I'm not touching that.
Discussion: https://www.postgresql.org/message-id/2330919b-62d9-29ac-8de3-58c024fdcb96@2ndquadrant.com
This is similar in spirit to the existing partbounds.c file in the
same directory, except that there's a lot less code in the new file
created by this commit. Pending work in this area proposes to add a
bunch more code related to PartitionDescs, though, and this will give
us a good place to put it.
Discussion: http://postgr.es/m/CA+TgmoZUwPf_uanjF==gTGBMJrn8uCq52XYvAEorNkLrUdoawg@mail.gmail.com
We should logically have allowed this case when we allowed zero-column
tables, but it was overlooked.
Although this might be thought a feature addition, it's really a bug
fix, because it was possible to create a zero-column view via
the convert-table-to-view code path, and then you'd have a situation
where dump/reload would fail. Hence, back-patch to all supported
branches.
Arrange the added test cases to provide coverage of the related
pg_dump code paths (since these views will be dumped and reloaded
during the pg_upgrade regression test). I also made them test
the case where pg_dump has to postpone the view rule into post-data,
which disturbingly had no regression coverage before.
Report and patch by Ashutosh Sharma (test case by me)
Discussion: https://postgr.es/m/CAE9k0PkmHdeSaeZt2ujnb_cKucmK3sDDceDzw7+d5UZoNJPYOg@mail.gmail.com
The original setup for dependencies of partitioned objects had
serious problems:
1. It did not verify that a drop cascading to a partition-child object
also cascaded to at least one of the object's partition parents. Now,
normally a child object would share all its dependencies with one or
another parent (e.g. a child index's opclass dependencies would be shared
with the parent index), so that this oversight is usually harmless.
But if some dependency failed to fit this pattern, the child could be
dropped while all its parents remain, creating a logically broken
situation. (It's easy to construct artificial cases that break it,
such as attaching an unrelated extension dependency to the child object
and then dropping the extension. I'm not sure if any less-artificial
cases exist.)
2. Management of partition dependencies during ATTACH/DETACH PARTITION
was complicated and buggy; for example, after detaching a partition
table it was possible to create cases where a formerly-child index
should be dropped and was not, because the correct set of dependencies
had not been reconstructed.
Less seriously, because multiple partition relationships were
represented identically in pg_depend, there was an order-of-traversal
dependency on which partition parent was cited in error messages.
We also had some pre-existing order-of-traversal hazards for error
messages related to internal and extension dependencies. This is
cosmetic to users but causes testing problems.
To fix#1, add a check at the end of the partition tree traversal
to ensure that at least one partition parent got deleted. To fix#2,
establish a new policy that partition dependencies are in addition to,
not instead of, a child object's usual dependencies; in this way
ATTACH/DETACH PARTITION need not cope with adding or removing the
usual dependencies.
To fix the cosmetic problem, distinguish between primary and secondary
partition dependency entries in pg_depend, by giving them different
deptypes. (They behave identically except for having different
priorities for being cited in error messages.) This means that the
former 'I' dependency type is replaced with new 'P' and 'S' types.
This also fixes a longstanding bug that after handling an internal
dependency by recursing to the owning object, findDependentObjects
did not verify that the current target was now scheduled for deletion,
and did not apply the current recursion level's objflags to it.
Perhaps that should be back-patched; but in the back branches it
would only matter if some concurrent transaction had removed the
internal-linkage pg_depend entry before the recursive call found it,
or the recursive call somehow failed to find it, both of which seem
unlikely.
Catversion bump because the contents of pg_depend change for
partitioning relationships.
Patch HEAD only. It's annoying that we're not fixing #2 in v11,
but there seems no practical way to do so given that the problem
is exactly a poor choice of what entries to put in pg_depend.
We can't really fix that while staying compatible with what's
in pg_depend in existing v11 installations.
Discussion: https://postgr.es/m/CAH2-Wzkypv1R+teZrr71U23J578NnTBt2X8+Y=Odr4pOdW1rXg@mail.gmail.com
After commit 123cc697a8, we remove redundant FK action triggers during
partition ATTACH by merely deleting the catalog tuple, but that's wrong:
it should use performDeletion() instead. Repair, and make the comments
more explicit.
Per code review from Tom Lane.
Discussion: https://postgr.es/m/18885.1549642539@sss.pgh.pa.us
Rename/repurpose pg_proc.protransform as "prosupport". The idea is
still that it names an internal function that provides knowledge to
the planner about the behavior of the function it's attached to;
but redesign the API specification so that it's not limited to doing
just one thing, but can support an extensible set of requests.
The original purpose of simplifying a function call is handled by
the first request type to be invented, SupportRequestSimplify.
Adjust all the existing transform functions to handle this API,
and rename them fron "xxx_transform" to "xxx_support" to reflect
the potential generalization of what they do. (Since we never
previously provided any way for extensions to add transform functions,
this change doesn't create an API break for them.)
Also add DDL and pg_dump support for attaching a support function to a
user-defined function. Unfortunately, DDL access has to be restricted
to superusers, at least for now; but seeing that support functions
will pretty much have to be written in C, that limitation is just
theoretical. (This support is untested in this patch, but a follow-on
patch will add cases that exercise it.)
Discussion: https://postgr.es/m/15193.1548028093@sss.pgh.pa.us
Previously heap_getattr() returned NULL for attributes with a fast
default value (c.f. 16828d5c02), as it had no handling whatsoever
for that case.
A previous fix, 7636e5c60f, attempted to fix issues caused by this
oversight, but just expanding OLD tuples for triggers doesn't actually
solve the underlying issue.
One known consequence of this bug is that the check for HOT updates
can return the wrong result, when a previously fast-default'ed column
is set to NULL. Which in turn means that an index over a column with
fast default'ed columns might be corrupt if the underlying column(s)
allow NULLs.
Fix by handling fast default columns in heap_getattr(), remove now
superfluous expansion in GetTupleForTrigger().
Author: Andres Freund
Discussion: https://postgr.es/m/20190201162404.onngi77f26baem4g@alap3.anarazel.de
Backpatch: 11, where fast defaults were introduced
We can't allow these pseudo-types to be used as table column types,
because storing an anonymous record value in a table would result
in data that couldn't be understood by other sessions. However,
it seems like there's no harm in allowing the case in a column
definition list that's specifying what a function-returning-record
returns. The data involved is all local to the current session,
so we should be just as able to resolve its actual tuple type as
we are for the function-returning-record's top-level tuple output.
Elvis Pranskevichus, with cosmetic changes by me
Discussion: https://postgr.es/m/11038447.kQ5A9Uj5xi@hammer.magicstack.net
Create a new header optimizer/optimizer.h, which exposes just the
planner functions that can be used "at arm's length", without need
to access Paths or the other planner-internal data structures defined
in nodes/relation.h. This is intended to provide the whole planner
API seen by most of the rest of the system; although FDWs still need
to use additional stuff, and more thought is also needed about just
what selfuncs.c should rely on.
The main point of doing this now is to limit the amount of new
#include baggage that will be needed by "planner support functions",
which I expect to introduce later, and which will be in relevant
datatype modules rather than anywhere near the planner.
This commit just moves relevant declarations into optimizer.h from
other header files (a couple of which go away because everything
got moved), and adjusts #include lists to match. There's further
cleanup that could be done if we want to decide that some stuff
being exposed by optimizer.h doesn't belong in the planner at all,
but I'll leave that for another day.
Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us
Move a few very simple node-creation and node-type-testing functions
from the planner's clauses.c to nodes/makefuncs and nodes/nodeFuncs.
There's nothing planner-specific about them, as evidenced by the
number of other places that were using them.
While at it, rename and_clause() etc to is_andclause() etc, to clarify
that they are node-type-testing functions not node-creation functions.
And use "static inline" implementations for the shortest ones.
Also, modify flatten_join_alias_vars() and some subsidiary functions
to take a Query not a PlannerInfo to define the join structure that
Vars should be translated according to. They were only using the
"parse" field of the PlannerInfo anyway, so this just requires removing
one level of indirection. The advantage is that now parse_agg.c can
use flatten_join_alias_vars() without the horrid kluge of creating an
incomplete PlannerInfo, which will allow that file to be decoupled from
relation.h in a subsequent patch.
Discussion: https://postgr.es/m/11460.1548706639@sss.pgh.pa.us
In batching mode, COPY was using the same (per-tuple) memory context for
allocations with longer lifetime. This was confusing but harmless, until
commit 31f3817402 added COPY FROM ... WHERE feature, introducing a risk
of memory leak.
The "per-tuple" memory context was reset only when starting new batch,
but as the rows may be filtered out by the WHERE clauses, that may not
happen at all. The WHERE clause however has to be evaluated for all
rows, before filtering them out.
This commit separates the per-tuple and per-batch contexts, removing the
ambiguity. Expressions (both defaults and WHERE clause) are evaluated
in the per-tuple context, while tuples are formed in the batch context.
This allows resetting the contexts at appropriate times.
The main complexity is related to partitioning, in which case we need to
reset the batch context after forming the tuple (which happens before
routing to leaf partition). Instead of switching between two contexts
as before, we simply copy the last tuple aside, reset the context and
then copy the tuple back. The performance impact is negligible, and
juggling with two contexts is not free either.
Discussion: https://www.postgresql.org/message-id/flat/CALAY4q_DdpWDuB5-Zyi-oTtO2uSk8pmy+dupiRe3AvAc++1imA@mail.gmail.com
Before this change FunctionCallInfoData, the struct arguments etc for
V1 function calls are stored in, always had space for
FUNC_MAX_ARGS/100 arguments, storing datums and their nullness in two
arrays. For nearly every function call 100 arguments is far more than
needed, therefore wasting memory. Arg and argnull being two separate
arrays also guarantees that to access a single argument, two
cachelines have to be touched.
Change the layout so there's a single variable-length array with pairs
of value / isnull. That drastically reduces memory consumption for
most function calls (on x86-64 a two argument function now uses
64bytes, previously 936 bytes), and makes it very likely that argument
value and its nullness are on the same cacheline.
Arguments are stored in a new NullableDatum struct, which, due to
padding, needs more memory per argument than before. But as usually
far fewer arguments are stored, and individual arguments are cheaper
to access, that's still a clear win. It's likely that there's other
places where conversion to NullableDatum arrays would make sense,
e.g. TupleTableSlots, but that's for another commit.
Because the function call information is now variable-length
allocations have to take the number of arguments into account. For
heap allocations that can be done with SizeForFunctionCallInfoData(),
for on-stack allocations there's a new LOCAL_FCINFO(name, nargs) macro
that helps to allocate an appropriately sized and aligned variable.
Some places with stack allocation function call information don't know
the number of arguments at compile time, and currently variably sized
stack allocations aren't allowed in postgres. Therefore allow for
FUNC_MAX_ARGS space in these cases. They're not that common, so for
now that seems acceptable.
Because of the need to allocate FunctionCallInfo of the appropriate
size, older extensions may need to update their code. To avoid subtle
breakages, the FunctionCallInfoData struct has been renamed to
FunctionCallInfoBaseData. Most code only references FunctionCallInfo,
so that shouldn't cause much collateral damage.
This change is also a prerequisite for more efficient expression JIT
compilation (by allocating the function call information on the stack,
allowing LLVM to optimize it away); previously the size of the call
information caused problems inside LLVM's optimizer.
Author: Andres Freund
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/20180605172952.x34m5uz6ju6enaem@alap3.anarazel.de
There were two flags used to track the access to temporary tables and
to the temporary namespace of a session which are used to restrict
PREPARE TRANSACTION, however the first control flag is a concept
included in the second. This removes the flag for temporary table
tracking, keeping around only the one at namespace level.
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/20190118053126.GH1883@paquier.xyz
GB18030's mblen() function looks at the first and the second byte of the
multibyte character, to determine its length. copy.c had made the
assumption that mblen() only looks at the first byte, but it turns out to
work out fine, because of the way the GB18030 encoding works. COPY will
see a 4-byte encoded character as two 2-byte encoded characters, which is
enough for COPY's purposes. It cannot mix those up with delimiter or
escaping characters, because only single-byte ASCII characters are
supported as delimiters or escape characters.
Discussion: https://www.postgresql.org/message-id/7704d099-9643-2a55-fb0e-becd64400dcb%40iki.fi
Previously, only literals were allowed. This change allows general
expressions, including functions calls, which are evaluated at the
time the DDL command is executed.
Besides offering some more functionality, it simplifies the parser
structures and removes some inconsistencies in how the literals were
handled.
Author: Kyotaro Horiguchi, Tom Lane, Amit Langote
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/9f88b5e0-6da2-5227-20d0-0d7012beaa1c@lab.ntt.co.jp/
We were failing to set conislocal correctly for constraints in
partitions after partition detach, leading to those constraints becoming
undroppable. Fix by setting the flag correctly. Existing databases
might contain constraints with the conislocal wrongly set to false, for
partitions that were detached; this situation should be fixable by
applying an UPDATE on pg_constraint to set conislocal true. This
problem should otherwise be innocuous and should disappear across a
dump/restore or pg_upgrade.
Secondarily, when constraint drop was attempted in a partitioned table,
ATExecDropConstraint would try to recurse to partitions after doing
performDeletion() of the constraint in the partitioned table itself; but
since the constraint in the partitions are dropped by the initial call
of performDeletion() (because of following dependencies), the recursion
step would fail since it would not find the constraint, causing the
whole operation to fail. Fix by preventing recursion.
Reported-by: Amit Langote
Diagnosed-by: Amit Langote
Author: Amit Langote, Álvaro Herrera
Discussion: https://postgr.es/m/f2b8ead5-4131-d5a8-8016-2ea0a31250af@lab.ntt.co.jp
Given these routines are heap specific, and that there will be more
generic visibility support in via table AM, it makes sense to move the
prototypes to heapam.h (routines like HeapTupleSatisfiesVacuum will
not be exposed in a generic fashion, because they are too storage
specific).
Similarly, the code in tqual.c is specific to heap, so moving it into
access/heap/ makes sense.
Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
The code in tqual.c is largely heap specific. Due to the upcoming
pluggable storage work, it therefore makes sense to move it into
access/heap/ (as the file's header notes, the tqual name isn't very
good).
But the various statically allocated snapshot and snapshot
initialization functions are now (see previous commit) generic and do
not depend on functions declared in tqual.h anymore. Therefore move.
Also move XidInMVCCSnapshot as that's useful for future AMs, and
already used outside of tqual.c.
Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
Detaching a partition from a partitioned table that's constrained by
foreign keys requires additional action triggers on the referenced side;
otherwise, DELETE/UPDATE actions there fail to notice rows in the table
that was partition, and so are incorrectly allowed through. With this
commit, those triggers are now created. Conversely, when a table that
has a foreign key is attached as a partition to a table that also has
the same foreign key, those action triggers are no longer needed, so we
remove them.
Add a minimal test case verifying (part of) this.
Authors: Amit Langote, Álvaro Herrera
Discussion: https://postgr.es/m/f2b8ead5-4131-d5a8-8016-2ea0a31250af@lab.ntt.co.jp
Most of these had been obsoleted by 568d4138c / the SnapshotNow
removal.
This is is preparation for moving most of tqual.[ch] into either
snapmgr.h or heapam.h, which in turn is in preparation for pluggable
table AMs.
Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
Extends the COPY FROM command with a WHERE condition, which allows doing
various types of filtering while importing the data (random sampling,
condition on a data column, etc.). Until now such filtering required
either preprocessing of the input data, or importing all data and then
filtering in the database. COPY FROM ... WHERE is an easy-to-use and
low-overhead alternative for most simple cases.
Author: Surafel Temesgen
Reviewed-by: Tomas Vondra, Masahiko Sawada, Lim Myungkyu
Discussion: https://www.postgresql.org/message-id/flat/CALAY4q_DdpWDuB5-Zyi-oTtO2uSk8pmy+dupiRe3AvAc++1imA@mail.gmail.com
When creating a foreign key in a partitioned table, if some partitions
already have equivalent constraints, we wastefully create duplicates of
the constraints instead of attaching to the existing ones. That's
inconsistent with the de-duplication that is applied when a table is
attached as a partition. To fix, reuse the FK-cloning code instead of
having a separate code path.
Backpatch to Postgres 11. This is a subtle behavior change, but surely
a welcome one since there's no use in having duplicate foreign keys.
Discovered by Álvaro Herrera while thinking about a different problem
reported by Jesper Pedersen (bug #15587).
Author: Álvaro Herrera
Discussion: https://postgr.es/m/201901151935.zfadrzvyof4k@alvherre.pgsql
My commit 3de241dba8 introduced some code to create a clone of a
foreign key to a partition, but I put it in pg_constraint.c because it
was too close to the contents of the pg_constraint row. With the
previous commit that split out the constraint tuple deconstruction into
its own routine, it makes more sense to have the FK-cloning function in
tablecmds.c, mostly because its static subroutine can then be used by a
future bugfix.
My initial posting of this patch had this routine as static in
tablecmds.c, but sadly this function is already part of the Postgres 11
ABI as exported from pg_constraint.c, so keep it as exported also just
to avoid breaking any possible users of it.
Attempting to use a temporary table within a two-phase transaction is
forbidden for ages. However, there have been uncovered grounds for
a couple of other object types and commands which work on temporary
objects with two-phase commit. In short, trying to create, lock or drop
an object on a temporary schema should not be authorized within a
two-phase transaction, as it would cause its state to create
dependencies with other sessions, causing all sorts of side effects with
the existing session or other sessions spawned later on trying to use
the same temporary schema name.
Regression tests are added to cover all the grounds found, the original
report mentioned function creation, but monitoring closer there are many
other patterns with LOCK, DROP or CREATE EXTENSION which are involved.
One of the symptoms resulting in combining both is that the session
which used the temporary schema is not able to shut down completely,
waiting for being able to drop the temporary schema, something that it
cannot complete because of the two-phase transaction involved with
temporary objects. In this case the client is able to disconnect but
the session remains alive on the backend-side, potentially blocking
connection backend slots from being used. Other problems reported could
also involve server crashes.
This is back-patched down to v10, which is where 9b013dc has introduced
MyXactFlags, something that this patch relies on.
Reported-by: Alexey Bashtanov
Author: Michael Paquier
Reviewed-by: Masahiko Sawada
Discussion: https://postgr.es/m/5d910e2e-0db8-ec06-dd5f-baec420513c3@imap.cc
Backpatch-through: 10
This is the genam.h equivalent of 4c850ecec6 (which removed
heapam.h from a lot of other headers). There's still a few header
includes of genam.h, but not from central headers anymore.
As a few headers are not indirectly included anymore, execnodes.h and
relscan.h need a few additional includes. Some of the depended on
types were replacable by using the underlying structs, but e.g. for
Snapshot in execnodes.h that'd have gotten more invasive than
reasonable in this commit.
Like the aforementioned commit 4c850ecec6, this requires adding new
genam.h includes to a number of backend files, which likely is also
required in a few external projects.
Author: Andres Freund
Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de
heapam.h previously was included in a number of widely used
headers (e.g. execnodes.h, indirectly in executor.h, ...). That's
problematic on its own, as heapam.h contains a lot of low-level
details that don't need to be exposed that widely, but becomes more
problematic with the upcoming introduction of pluggable table storage
- it seems inappropriate for heapam.h to be included that widely
afterwards.
heapam.h was largely only included in other headers to get the
HeapScanDesc typedef (which was defined in heapam.h, even though
HeapScanDescData is defined in relscan.h). The better solution here
seems to be to just use the underlying struct (forward declared where
necessary). Similar for BulkInsertState.
Another problem was that LockTupleMode was used in executor.h - parts
of the file tried to cope without heapam.h, but due to the fact that
it indirectly included it, several subsequent violations of that goal
were not not noticed. We could just reuse the approach of declaring
parameters as int, but it seems nicer to move LockTupleMode to
lockoptions.h - that's not a perfect location, but also doesn't seem
bad.
As a number of files relied on implicitly included heapam.h, a
significant number of files grew an explicit include. It's quite
probably that a few external projects will need to do the same.
Author: Andres Freund
Reviewed-By: Alvaro Herrera
Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de
This was an oversight in commit 16828d5c. If the table is going to be
rewritten, we simply clear all the missing values from all the table's
attributes, since there will no longer be any rows with the attributes
missing. Otherwise, we repackage the missing value in an array
constructed with the new type specifications.
Backpatch to release 11.
This fixes bug #15446, reported by Dmitry Molotkov
Reviewed by Dean Rasheed
This patch changes the rule for whether or not a tuple seen by ANALYZE
should be included in its sample.
When we last touched this logic, in commit 51e1445f1, we weren't
thinking very hard about tuples being UPDATEd by a long-running
concurrent transaction. In such a case, we might see the pre-image as
either LIVE or DELETE_IN_PROGRESS depending on timing; and we might see
the post-image not at all, or as INSERT_IN_PROGRESS. Since the existing
code will not sample either DELETE_IN_PROGRESS or INSERT_IN_PROGRESS
tuples, this leads to concurrently-updated rows being omitted from the
sample entirely. That's not very helpful, and it's especially the wrong
thing if the concurrent transaction ends up rolling back.
The right thing seems to be to sample DELETE_IN_PROGRESS rows just as if
they were live. This makes the "sample it" and "count it" decisions the
same, which seems good for consistency. It's clearly the right thing
if the concurrent transaction ends up rolling back; in effect, we are
sampling as though IN_PROGRESS transactions haven't happened yet.
Also, this combination of choices ensures maximum robustness against
the different combinations of whether and in which state we might see the
pre- and post-images of an update.
It's slightly annoying that we end up recording immediately-out-of-date
stats in the case where the transaction does commit, but on the other
hand the stats are fine for columns that didn't change in the update.
And the alternative of sampling INSERT_IN_PROGRESS rows instead seems
like a bad idea, because then the sampling would be inconsistent with
the way rows are counted for the stats report.
Per report from Mark Chambers; thanks to Jeff Janes for diagnosing
what was happening. Back-patch to all supported versions.
Discussion: https://postgr.es/m/CAFh58O_Myr6G3tcH3gcGrF-=OExB08PJdWZcSBcEcovaiPsrHA@mail.gmail.com
In commit 8b08f7d482 I added member relationId to IndexStmt struct.
I'm now not sure why; DefineIndex doesn't need it, since the relation
OID is passed as a separate argument anyway. Remove it.
Also remove a redundant assignment to the relationId argument (it wasn't
redundant when added by commit e093dcdd28, but should have been removed
in commit 5f173040e3), and use relationId instead of stmt->relation when
locking the relation in the second phase of CREATE INDEX CONCURRENTLY,
which is not only confusing but it means we resolve the name twice for
no reason.
Inheritance trees can include temporary tables if the parent is
permanent, which makes possible the presence of multiple temporary
children from different sessions. Trying to issue a TRUNCATE on the
parent in this scenario causes a failure, so similarly to any other
queries just ignore such cases, which makes TRUNCATE work
transparently.
This makes truncation behave similarly to any other DML query working on
the parent table with queries which need to be work on the children. A
set of isolation tests is added to cover basic cases.
Reported-by: Zhou Digoal
Author: Amit Langote, Michael Paquier
Discussion: https://postgr.es/m/15565-ce67a48d0244436a@postgresql.org
Backpatch-through: 9.4
COPY can skip writing WAL when loading data on a table which has been
created in the same transaction as the one loading the data, however
this cannot work on views or foreign table as this would result in
trying to flush relation files which do not exist. So disable the
optimization so as commands are able to work the same way with any
configuration of wal_level.
Tests are added to cover the different cases, which need to have
wal_level set to minimal to allow the problem to show up, and that is
not the default configuration.
Reported-by: Luis M. Carril, Etsuro Fujita
Author: Amit Langote, Michael Paquier
Reviewed-by: Etsuro Fujita
Discussion: https://postgr.es/m/15552-c64aa14c5c22f63c@postgresql.org
Backpatch-through: 10, where support for COPY on views has been added,
while v11 has added support for COPY on foreign tables.
For probably bogus reasons, we acquire only AccessShareLock on the
partition when we try to detach it from its parent partitioned table.
This can cause ugly things to happen if another transaction is doing
any sort of DDL to the partition concurrently.
Upgrade that lock to ShareUpdateExclusiveLock, which per discussion
seems to be the minimum needed.
Reported by Robert Haas.
Discussion: https://postgr.es/m/CA+TgmoYruJQ+2qnFLtF1xQtr71pdwgfxy3Ziy-TxV28M6pEmyA@mail.gmail.com
When a partition is detached from its parent, we acquire locks on all
attached indexes to also detach them ... but we release those locks
immediately. This is a violation of the policy of keeping locks on user
objects to the end of the transaction. Bug introduced in 8b08f7d482.
It's unclear that there are any ill effects possible, but it's clearly
wrong nonetheless. It's likely that bad behavior *is* possible, but
mostly because the relation that the index is for is only locked with
AccessShareLock, which is an older bug that shall be fixed separately.
While touching that line of code, close the index opened with
index_open() using index_close() instead of relation_close().
No difference in practice, but let's be consistent.
Unearthed by Robert Haas.
Discussion: https://postgr.es/m/CA+TgmoYruJQ+2qnFLtF1xQtr71pdwgfxy3Ziy-TxV28M6pEmyA@mail.gmail.com
The flag for IF NOT EXISTS was only being passed down in the normal
recursing case. It's been this way since originally added in 9.6 in
commit 2cd40adb85 so backpatch back to 9.6.
The "name" comparison operators now all support collations, making them
functionally equivalent to "text" comparisons, except for the different
physical representation of the datatype. They do, in fact, mostly share
the varstr_cmp and varstr_sortsupport infrastructure, which has been
slightly enlarged to handle the case.
To avoid changes in the default behavior of the datatype, set name's
typcollation to C_COLLATION_OID not DEFAULT_COLLATION_OID, so that
by default comparisons to a name value will continue to use strcmp
semantics. (This would have been the case for system catalog columns
anyway, because of commit 6b0faf723, but doing this makes it true for
user-created name columns as well. In particular, this avoids
locale-dependent changes in our regression test results.)
In consequence, tweak a couple of places that made assumptions about
collatable base types always having typcollation DEFAULT_COLLATION_OID.
I have not, however, attempted to relax the restriction that user-
defined collatable types must have that. Hence, "name" doesn't
behave quite like a user-defined type; it acts more like a domain
with COLLATE "C". (Conceivably, if we ever get rid of the need for
catalog name columns to be fixed-length, "name" could actually become
such a domain over text. But that'd be a pretty massive undertaking,
and I'm not volunteering.)
Discussion: https://postgr.es/m/15938.1544377821@sss.pgh.pa.us
When partitioned tables were introduced, we failed to realize that by
copying the tablespace handling for other relation kinds with no
physical storage we were causing the secondary effect that their
partitions would not automatically inherit the tablespace setting. This
is surprising and unhelpful, so change it to adopt the behavior
introduced in pg11 (commit 33e6c34c32) for partitioned indexes: the
parent relation remembers the tablespace specification, which is then
used for any new partitions that don't declare one.
Because this commit changes behavior of the TABLESPACE clause for
partitioned tables (it's no longer a no-op), it is not backpatched.
Author: David Rowley, Álvaro Herrera
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/CAKJS1f9SxVzqDrGD1teosFd6jBMM0UEaa14_8mRvcWE19Tu0hA@mail.gmail.com
This is an oversight from recent commit b13fd344. While on it, tweak
the previous test with a better name for the renamed primary key.
Detected by buildfarm member prion which forces relation cache release
with -DRELCACHE_FORCE_RELEASE. Back-patch down to 9.4 as the previous
commit.
When a constraint gets renamed, it may have associated with it a target
relation (for example domain constraints don't have one). Not
invalidating the target relation cache when issuing the renaming can
result in issues with subsequent commands that refer to the old
constraint name using the relation cache, causing various failures. One
pattern spotted was using CREATE TABLE LIKE after a constraint
renaming.
Reported-by: Stuart <sfbarbee@gmail.com>
Author: Amit Langote
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/2047094.V130LYfLq4@station53.ousa.org
Commit ffa4cbd62 added logic to detect SIGPIPE failure of a COPY child
process, but it only worked correctly if the SIGPIPE occurred in the
immediate child process. Depending on the shell in use and the
complexity of the shell command string, we might instead get back
an exit code of 128 + SIGPIPE, representing a shell error exit
reporting SIGPIPE in the child process.
We could just hack up ClosePipeToProgram() to add the extra case,
but it seems like this is a fairly general issue deserving a more
general and better-documented solution. I chose to add a couple
of functions in src/common/wait_error.c, which is a natural place
to know about wait-result encodings, that will test for either a
specific child-process signal type or any child-process signal failure.
Then, adjust other places that were doing ad-hoc tests of this type
to use the common functions.
In RestoreArchivedFile, this fixes a race condition affecting whether
the process will report an error or just silently proc_exit(1): before,
that depended on whether the intermediate shell got SIGTERM'd itself
or reported a child process failing on SIGTERM.
Like the previous patch, back-patch to v10; we could go further
but there seems no real need to.
Per report from Erik Rijkers.
Discussion: https://postgr.es/m/f3683f87ab1701bea5d86a7742b22432@xs4all.nl
When we first put in collations support, we basically punted on teaching
pg_statistic, ANALYZE, and the planner selectivity functions about that.
They've just used DEFAULT_COLLATION_OID independently of the actual
collation of the data. It's time to improve that, so:
* Add columns to pg_statistic that record the specific collation associated
with each statistics slot.
* Teach ANALYZE to use the column's actual collation when comparing values
for statistical purposes, and record this in the appropriate slot. (Note
that type-specific typanalyze functions are now expected to fill
stats->stacoll with the appropriate collation, too.)
* Teach assorted selectivity functions to use the actual collation of
the stats they are looking at, instead of just assuming it's
DEFAULT_COLLATION_OID.
This should give noticeably better results in selectivity estimates for
columns with nondefault collations, at least for query clauses that use
that same collation (which would be the default behavior in most cases).
It's still true that comparisons with explicit COLLATE clauses different
from the stored data's collation won't be well-estimated, but that's no
worse than before. Also, this patch does make the first step towards
doing better with that, which is that it's now theoretically possible to
collect stats for a collation other than the column's own collation.
Patch by me; thanks to Peter Eisentraut for review.
Discussion: https://postgr.es/m/14706.1544630227@sss.pgh.pa.us
If a domain has no constraints, then CoerceToDomain doesn't really do
anything and can be simplified to a RelabelType. This not only
eliminates cycles at execution, but allows the planner to optimize better
(for instance, match the coerced expression to an index on the underlying
column). However, we do have to support invalidating the plan later if
a constraint gets added to the domain. That's comparable to the case of
a change to a SQL function that had been inlined into a plan, so all the
necessary logic already exists for plans depending on functions. We
need only duplicate or share that logic for domains.
ALTER DOMAIN ADD/DROP CONSTRAINT need to be taught to send out sinval
messages for the domain's pg_type entry, since those operations don't
update that row. (ALTER DOMAIN SET/DROP NOT NULL do update that row,
so no code change is needed for them.)
Testing this revealed what's really a pre-existing bug in plpgsql:
it caches the SQL-expression-tree expansion of type coercions and
had no provision for invalidating entries in that cache. Up to now
that was only a problem if such an expression had inlined a SQL
function that got changed, which is unlikely though not impossible.
But failing to track changes of domain constraints breaks an existing
regression test case and would likely cause practical problems too.
We could fix that locally in plpgsql, but what seems like a better
idea is to build some generic infrastructure in plancache.c to store
standalone expressions and track invalidation events for them.
(It's tempting to wonder whether plpgsql's "simple expression" stuff
could use this code with lower overhead than its current use of the
heavyweight plancache APIs. But I've left that idea for later.)
Other stuff fixed in passing:
* Allow estimate_expression_value() to drop CoerceToDomain
unconditionally, effectively assuming that the coercion will succeed.
This will improve planner selectivity estimates for cases involving
estimatable expressions that are coerced to domains. We could have
done this independently of everything else here, but there wasn't
previously any need for eval_const_expressions_mutator to know about
CoerceToDomain at all.
* Use a dlist for plancache.c's list of cached plans, rather than a
manually threaded singly-linked list. That eliminates a potential
performance problem in DropCachedPlan.
* Fix a couple of inconsistencies in typecmds.c about whether
operations on domains drop RowExclusiveLock on pg_type. Our common
practice is that DDL operations do drop catalog locks, so standardize
on that choice.
Discussion: https://postgr.es/m/19958.1544122124@sss.pgh.pa.us
The stanza of ExecuteTruncate[Guts] that truncates a target table's toast
relation re-used the loop local variable "rel" to reference the toast rel.
This was safe enough when written, but commit d42358efb added code below
that that supposed "rel" still pointed to the parent table. Therefore,
the stats counter update was applied to the wrong relcache entry (the
toast rel not the user rel); and if we were unlucky and that relcache
entry had been flushed during reindex_relation, very bad things could
ensue.
(I'm surprised that CLOBBER_CACHE_ALWAYS testing hasn't found this.
I'm even more surprised that the problem wasn't detected during the
development of d42358efb; it must not have been tested in any case
with a toast table, as the incorrect stats counts are very obvious.)
To fix, replace use of "rel" in that code branch with a more local
variable. Adjust test cases added by d42358efb so that some of them
use tables with toast tables.
Per bug #15540 from Pan Bian. Back-patch to 9.5 where d42358efb came in.
Discussion: https://postgr.es/m/15540-01078812338195c0@postgresql.org
Remove dead code (which would be incorrect if it weren't dead),
per report from Pan Bian. Add a CHECK_FOR_INTERRUPTS in the
inner loop over child relations, because there's little point
in having one in the outer loop if there's not one here too.
Minor stylistic adjustments and comment improvements.
Seems to be aboriginal to this code (cf commit 665d1fad9).
Back-patch to v10 where that came in, not because any of this
is significant, but just to keep the branches looking similar.
Discussion: https://postgr.es/m/15539-06d00ef6b1e2e1bb@postgresql.org
As per the error message style guide of the documentation, those should
be full sentences.
Author: Daniel Gustafsson
Reviewed-by: Michael Paquier, Álvaro Herrera
Discussion: https://1E8D49B4-16BC-4420-B4ED-58501D9E076B@yesql.se
When an indexes is created on a partitioned table using ONLY (don't
recurse to partitions), it gets marked invalid until index partitions
are attached for each table partition. But there's no reason to do this
if there are no partitions ... and moreover, there's no way to get the
index to become valid afterwards, because all partitions that get
created/attached get their own index partition already attached to the
parent index, so there's no chance to do ALTER INDEX ... ATTACH PARTITION
that would make the parent index valid.
Fix by not marking the index as invalid to begin with.
This is very similar to 9139aa1942, but the pg_dump aspect does not
appear to be relevant until we add FKs that can point to PKs on
partitioned tables. (I tried to cause the pg_upgrade test to break by
leaving some of these bogus tables around, but wasn't able to.)
Making this change means that an index that was supposed to be invalid
in the insert_conflict regression test is no longer invalid; reorder the
DDL so that the test continues to verify the behavior we want it to.
Author: Álvaro Herrera
Reviewed-by: Amit Langote
Discussion: https://postgr.es/m/20181203225019.2vvdef2ybnkxt364@alvherre.pgsql
recovery.conf settings are now set in postgresql.conf (or other GUC
sources). Currently, all the affected settings are PGC_POSTMASTER;
this could be refined in the future case by case.
Recovery is now initiated by a file recovery.signal. Standby mode is
initiated by a file standby.signal. The standby_mode setting is
gone. If a recovery.conf file is found, an error is issued.
The trigger_file setting has been renamed to promote_trigger_file as
part of the move.
The documentation chapter "Recovery Configuration" has been integrated
into "Server Configuration".
pg_basebackup -R now appends settings to postgresql.auto.conf and
creates a standby.signal file.
Author: Fujii Masao <masao.fujii@gmail.com>
Author: Simon Riggs <simon@2ndquadrant.com>
Author: Abhijit Menon-Sen <ams@2ndquadrant.com>
Author: Sergei Kornilov <sk@zsrv.org>
Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
Previously tables declared WITH OIDS, including a significant fraction
of the catalog tables, stored the oid column not as a normal column,
but as part of the tuple header.
This special column was not shown by default, which was somewhat odd,
as it's often (consider e.g. pg_class.oid) one of the more important
parts of a row. Neither pg_dump nor COPY included the contents of the
oid column by default.
The fact that the oid column was not an ordinary column necessitated a
significant amount of special case code to support oid columns. That
already was painful for the existing, but upcoming work aiming to make
table storage pluggable, would have required expanding and duplicating
that "specialness" significantly.
WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0).
Remove it.
Removing includes:
- CREATE TABLE and ALTER TABLE syntax for declaring the table to be
WITH OIDS has been removed (WITH (oids[ = true]) will error out)
- pg_dump does not support dumping tables declared WITH OIDS and will
issue a warning when dumping one (and ignore the oid column).
- restoring an pg_dump archive with pg_restore will warn when
restoring a table with oid contents (and ignore the oid column)
- COPY will refuse to load binary dump that includes oids.
- pg_upgrade will error out when encountering tables declared WITH
OIDS, they have to be altered to remove the oid column first.
- Functionality to access the oid of the last inserted row (like
plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed.
The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false)
for CREATE TABLE) is still supported. While that requires a bit of
support code, it seems unnecessary to break applications / dumps that
do not use oids, and are explicit about not using them.
The biggest user of WITH OID columns was postgres' catalog. This
commit changes all 'magic' oid columns to be columns that are normally
declared and stored. To reduce unnecessary query breakage all the
newly added columns are still named 'oid', even if a table's column
naming scheme would indicate 'reloid' or such. This obviously
requires adapting a lot code, mostly replacing oid access via
HeapTupleGetOid() with access to the underlying Form_pg_*->oid column.
The bootstrap process now assigns oids for all oid columns in
genbki.pl that do not have an explicit value (starting at the largest
oid previously used), only oids assigned later by oids will be above
FirstBootstrapObjectId. As the oid column now is a normal column the
special bootstrap syntax for oids has been removed.
Oids are not automatically assigned during insertion anymore, all
backend code explicitly assigns oids with GetNewOidWithIndex(). For
the rare case that insertions into the catalog via SQL are called for
the new pg_nextoid() function can be used (which only works on catalog
tables).
The fact that oid columns on system tables are now normal columns
means that they will be included in the set of columns expanded
by * (i.e. SELECT * FROM pg_class will now include the table's oid,
previously it did not). It'd not technically be hard to hide oid
column by default, but that'd mean confusing behavior would either
have to be carried forward forever, or it'd cause breakage down the
line.
While it's not unlikely that further adjustments are needed, the
scope/invasiveness of the patch makes it worthwhile to get merge this
now. It's painful to maintain externally, too complicated to commit
after the code code freeze, and a dependency of a number of other
patches.
Catversion bump, for obvious reasons.
Author: Andres Freund, with contributions by John Naylor
Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de
Per POSIX, WIFSIGNALED and related macros are provided by <sys/wait.h>.
Apparently on Linux they're also pulled in by some other inclusions,
but BSD-ish systems are pickier. Fixes portability issue in ffa4cbd62.
Per buildfarm.
Previously, any program launched by COPY TO/FROM PROGRAM inherited the
server's setting of SIGPIPE handling, i.e. SIG_IGN. Hence, if we were
doing COPY FROM PROGRAM and closed the pipe early, the child process
would see EPIPE on its output file and typically would treat that as
a fatal error, in turn causing the COPY to report error. Similarly,
one could get a failure report from a query that didn't read all of
the output from a contrib/file_fdw foreign table that uses file_fdw's
PROGRAM option.
To fix, ensure that child programs inherit SIG_DFL not SIG_IGN processing
of SIGPIPE. This seems like an all-around better situation since if
the called program wants some non-default treatment of SIGPIPE, it would
expect to have to set that up for itself. Then in COPY, if it's COPY
FROM PROGRAM and we stop reading short of detecting EOF, treat a SIGPIPE
exit from the called program as a non-error condition. This still allows
us to report an error for any case where the called program gets SIGPIPE
on some other file descriptor.
As coded, we won't report a SIGPIPE if we stop reading as a result of
seeing an in-band EOF marker (e.g. COPY BINARY EOF marker). It's
somewhat debatable whether we should complain if the called program
continues to transmit data after an EOF marker. However, it seems like
we should avoid throwing error in any questionable cases, especially in a
back-patched fix, and anyway it would take additional code to make such
an error get reported consistently.
Back-patch to v10. We could go further back, since COPY FROM PROGRAM
has been around awhile, but AFAICS the only way to reach this situation
using core or contrib is via file_fdw, which has only supported PROGRAM
sources since v10. The COPY statement per se has no feature whereby
it'd stop reading without having hit EOF or an error already. Therefore,
I don't see any upside to back-patching further that'd outweigh the
risk of complaints about behavioral change.
Per bug #15449 from Eric Cyr.
Patch by me, review by Etsuro Fujita and Kyotaro Horiguchi
Discussion: https://postgr.es/m/15449-1cf737dd5929450e@postgresql.org
This didn't actually work: COPY would fail to flush the right files, and
instead would try to flush a non-existing file, causing the whole
transaction to fail.
Cope by raising an error as soon as the command is sent instead, to
avoid a nasty later surprise. Of course, it would be much better to
make it work, but we don't have a patch for that yet, and we don't know
if we'll want to backpatch one when we do.
Reported-by: Tomas Vondra
Author: David Rowley
Reviewed-by: Amit Langote, Steve Singer, Tomas Vondra
This commit completes the work prepared in 1a0586de36, splitting the
old TupleTableSlot implementation (which could store buffer, heap,
minimal and virtual slots) into four different slot types. As
described in the aforementioned commit, this is done with the goal of
making tuple table slots extensible, to allow for pluggable table
access methods.
To achieve runtime extensibility for TupleTableSlots, operations on
slots that can differ between types of slots are performed using the
TupleTableSlotOps struct provided at slot creation time. That
includes information from the size of TupleTableSlot struct to be
allocated, initialization, deforming etc. See the struct's definition
for more detailed information about callbacks TupleTableSlotOps.
I decided to rename TTSOpsBufferTuple to TTSOpsBufferHeapTuple and
ExecCopySlotTuple to ExecCopySlotHeapTuple, as that seems more
consistent with other naming introduced in recent patches.
There's plenty optimization potential in the slot implementation, but
according to benchmarking the state after this commit has similar
performance characteristics to before this set of changes, which seems
sufficient.
There's a few changes in execReplication.c that currently need to poke
through the slot abstraction, that'll be repaired once the pluggable
storage patchset provides the necessary infrastructure.
Author: Andres Freund and Ashutosh Bapat, with changes by Amit Khandekar
Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
This speeds up write operations (INSERT, UPDATE, DELETE, COPY, as well
as the future MERGE) on partitioned tables.
This changes the setup for tuple routing so that it does far less work
during the initial setup and pushes more work out to when partitions
receive tuples. PartitionDispatchData structs for sub-partitioned
tables are only created when a tuple gets routed through it. The
possibly large arrays in the PartitionTupleRouting struct have largely
been removed. The partitions[] array remains but now never contains any
NULL gaps. Previously the NULLs had to be skipped during
ExecCleanupTupleRouting(), which could add a large overhead to the
cleanup when the number of partitions was large. The partitions[] array
is allocated small to start with and only enlarged when we route tuples
to enough partitions that it runs out of space. This allows us to keep
simple single-row partition INSERTs running quickly. Redesign
The arrays in PartitionTupleRouting which stored the tuple translation maps
have now been removed. These have been moved out into a
PartitionRoutingInfo struct which is an additional field in ResultRelInfo.
The find_all_inheritors() call still remains by far the slowest part of
ExecSetupPartitionTupleRouting(). This commit just removes the other slow
parts.
In passing also rename the tuple translation maps from being ParentToChild
and ChildToParent to being RootToPartition and PartitionToRoot. The old
names mislead you into thinking that a partition of some sub-partitioned
table would translate to the rowtype of the sub-partitioned table rather
than the root partitioned table.
Authors: David Rowley and Amit Langote, heavily revised by Álvaro Herrera
Testing help from Jesper Pedersen and Kato Sho.
Discussion: https://postgr.es/m/CAKJS1f_1RJyFquuCKRFHTdcXqoPX-PYqAd7nz=GVBwvGh4a6xA@mail.gmail.com
Upcoming work intends to allow pluggable ways to introduce new ways of
storing table data. Accessing those table access methods from the
executor requires TupleTableSlots to be carry tuples in the native
format of such storage methods; otherwise there'll be a significant
conversion overhead.
Different access methods will require different data to store tuples
efficiently (just like virtual, minimal, heap already require fields
in TupleTableSlot). To allow that without requiring additional pointer
indirections, we want to have different structs (embedding
TupleTableSlot) for different types of slots. Thus different types of
slots are needed, which requires adapting creators of slots.
The slot that most efficiently can represent a type of tuple in an
executor node will often depend on the type of slot a child node
uses. Therefore we need to track the type of slot is returned by
nodes, so parent slots can create slots based on that.
Relatedly, JIT compilation of tuple deforming needs to know which type
of slot a certain expression refers to, so it can create an
appropriate deforming function for the type of tuple in the slot.
But not all nodes will only return one type of slot, e.g. an append
node will potentially return different types of slots for each of its
subplans.
Therefore add function that allows to query the type of a node's
result slot, and whether it'll always be the same type (whether it's
fixed). This can be queried using ExecGetResultSlotOps().
The scan, result, inner, outer type of slots are automatically
inferred from ExecInitScanTupleSlot(), ExecInitResultSlot(),
left/right subtrees respectively. If that's not correct for a node,
that can be overwritten using new fields in PlanState.
This commit does not introduce the actually abstracted implementation
of different kind of TupleTableSlots, that will be left for a followup
commit. The different types of slots introduced will, for now, still
use the same backing implementation.
While this already partially invalidates the big comment in
tuptable.h, it seems to make more sense to update it later, when the
different TupleTableSlot implementations actually exist.
Author: Ashutosh Bapat and Andres Freund, with changes by Amit Khandekar
Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
Previously materializing a slot always returned a HeapTuple. As
current work aims to reduce the reliance on HeapTuples (so other
storage systems can work efficiently), that needs to change. Thus
split the tasks of materializing a slot (i.e. making it independent
from the underlying storage / other memory contexts) from fetching a
HeapTuple from the slot. For brevity, allow to fetch a HeapTuple from
a slot and materializing the slot at the same time, controlled by a
parameter.
For now some callers of ExecFetchSlotHeapTuple, with materialize =
true, expect that changes to the heap tuple will be reflected in the
underlying slot. Those places will be adapted in due course, so while
not pretty, that's OK for now.
Also rename ExecFetchSlotTuple to ExecFetchSlotHeapTupleDatum and
ExecFetchSlotTupleDatum to ExecFetchSlotHeapTupleDatum, as it's likely
that future storage methods will need similar methods. There already
is ExecFetchSlotMinimalTuple, so the new names make the naming scheme
more coherent.
Author: Ashutosh Bapat and Andres Freund, with changes by Amit Khandekar
Discussion: https://postgr.es/m/20181105210039.hh4vvi4vwoq5ba2q@alap3.anarazel.de
Change lock level for renaming index (either ALTER INDEX or implicitly
via some other commands) from AccessExclusiveLock to
ShareUpdateExclusiveLock.
One reason we need a strong lock for relation renaming is that the
name change causes a rebuild of the relcache entry. Concurrent
sessions that have the relation open might not be able to handle the
relcache entry changing underneath them. Therefore, we need to lock
the relation in a way that no one can have the relation open
concurrently. But for indexes, the relcache handles reloads specially
in RelationReloadIndexInfo() in a way that keeps changes in the
relcache entry to a minimum. As long as no one keeps pointers to
rd_amcache and rd_options around across possible relcache flushes,
which is the case, this ought to be safe.
We also want to use a self-exclusive lock for correctness, so that
concurrent DDL doesn't overwrite the rename if they start updating
while still seeing the old version. Therefore, we use
ShareUpdateExclusiveLock, which is already used by other DDL commands
that want to operate in a concurrent manner.
The reason this is interesting at all is that renaming an index is a
typical part of a concurrent reindexing workflow (CREATE INDEX
CONCURRENTLY new + DROP INDEX CONCURRENTLY old + rename back). And
indeed a future built-in REINDEX CONCURRENTLY might rely on the ability
to do concurrent renames as well.
Reviewed-by: Andrey Klychkov <aaklychkov@mail.ru>
Reviewed-by: Fabrízio de Royes Mello <fabriziomello@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/1531767486.432607658@f357.i.mail.ru
This comes from f9b5b41, which is part of one the original commits that
implemented ON COMMIT actions. By looking at the truncation code, any
CCI needed happens locally when rebuilding indexes, so it looks safe to
just remove this final incrementation.
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/20181109024731.GF2652@paquier.xyz
There's no point in asking deconstruct_array() for a null-flags
array when we already checked the array has no nulls, and aren't
going to examine the output anyhow. Not asking for this output
should make the code marginally faster, and it's also more
robust since if there somehow were nulls, deconstruct_array()
would throw an error.
Daniel Gustafsson
Discussion: https://postgr.es/m/289FFB8B-7AAB-48B5-A497-6E0D41D7BA47@yesql.se
The tests added in cfa0f4255b to skip
firing an RI trigger if any old key value is NULL can also be applied
for DELETE. This should give a performance gain in those cases, and it
also saves a lot of duplicate code in the actual RI triggers. (That
code was already dead code for the UPDATE cases.)
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
This patch fixes several related cases in which pg_shdepend entries were
never made, or were lost, for references to roles appearing in the ACLs of
schemas and/or types. While that did no immediate harm, if a referenced
role were later dropped, the drop would be allowed and would leave a
dangling reference in the object's ACL. That still wasn't a big problem
for normal database usage, but it would cause obscure failures in
subsequent dump/reload or pg_upgrade attempts, taking the form of
attempts to grant privileges to all-numeric role names. (I think I've
seen field reports matching that symptom, but can't find any right now.)
Several cases are fixed here:
1. ALTER DOMAIN SET/DROP DEFAULT would lose the dependencies for any
existing ACL entries for the domain. This case is ancient, dating
back as far as we've had pg_shdepend tracking at all.
2. If a default type privilege applies, CREATE TYPE recorded the
ACL properly but forgot to install dependency entries for it.
This dates to the addition of default privileges for types in 9.2.
3. If a default schema privilege applies, CREATE SCHEMA recorded the
ACL properly but forgot to install dependency entries for it.
This dates to the addition of default privileges for schemas in v10
(commit ab89e465c).
Another somewhat-related problem is that when creating a relation
rowtype or implicit array type, TypeCreate would apply any available
default type privileges to that type, which we don't really want
since such an object isn't supposed to have privileges of its own.
(You can't, for example, drop such privileges once they've been added
to an array type.)
ab89e465c is also to blame for a race condition in the regression tests:
privileges.sql transiently installed globally-applicable default
privileges on schemas, which sometimes got absorbed into the ACLs of
schemas created by concurrent test scripts. This should have resulted
in failures when privileges.sql tried to drop the role holding such
privileges; but thanks to the bug fixed here, it instead led to dangling
ACLs in the final state of the regression database. We'd managed not to
notice that, but it became obvious in the wake of commit da906766c, which
allowed the race condition to occur in pg_upgrade tests.
To fix, add a function recordDependencyOnNewAcl to encapsulate what
callers of get_user_default_acl need to do; while the original call
sites got that right via ad-hoc code, none of the later-added ones
have. Also change GenerateTypeDependencies to generate these
dependencies, which requires adding the typacl to its parameter list.
(That might be annoying if there are any extensions calling that
function directly; but if there are, they're most likely buggy in the
same way as the core callers were, so they need work anyway.) While
I was at it, I changed GenerateTypeDependencies to accept most of its
parameters in the form of a Form_pg_type pointer, making its parameter
list a bit less unwieldy and mistake-prone.
The test race condition is fixed just by wrapping the addition and
removal of default privileges into a single transaction, so that that
state is never visible externally. We might eventually prefer to
separate out tests of default privileges into a script that runs by
itself, but that would be a bigger change and would make the tests
run slower overall.
Back-patch relevant parts to all supported branches.
Discussion: https://postgr.es/m/15719.1541725287@sss.pgh.pa.us
This commit fixes a set of issues with ON COMMIT actions when used on
partitioned tables and tables with inheritance children:
- Applying ON COMMIT DROP on a partitioned table with partitions or on a
table with inheritance children caused a failure at commit time, with
complains about the children being already dropped as all relations are
dropped one at the same time.
- Applying ON COMMIT DELETE on a partition relying on a partitioned
table which uses ON COMMIT DROP would cause the partition truncation to
fail as the parent is removed first.
The solution to the first problem is to handle the removal of all the
dependencies in one go instead of dropping relations one-by-one, based
on a suggestion from Álvaro Herrera. So instead all the relation OIDs
to remove are gathered and then processed in one round of multiple
deletions.
The solution to the second problem is to reorder the actions, with
truncation happening first and relation drop done after. Even if it
means that a partition could be first truncated, then immediately
dropped if its partitioned table is dropped, this has the merit to keep
the code simple as there is no need to do existence checks on the
relations to drop.
Contrary to a manual TRUNCATE on a partitioned table, ON COMMIT DELETE
does not cascade to its partitions. The ON COMMIT action defined on
each partition gets the priority.
Author: Michael Paquier
Reviewed-by: Amit Langote, Álvaro Herrera, Robert Haas
Discussion: https://postgr.es/m/68f17907-ec98-1192-f99f-8011400517f5@lab.ntt.co.jp
Backpatch-through: 10
The original code to propagate NOT NULL and default expressions
specified when creating a partition was mostly copy-pasted from
typed-tables creation, but not being a great match it contained some
duplicity, inefficiency and bugs.
This commit fixes the bug that NOT NULL constraints declared in the
parent table would not be honored in the partition. One reported issue
that is not fixed is that a DEFAULT declared in the child is not used
when inserting through the parent. That would amount to a behavioral
change that's better not back-patched.
This rewrite makes the code simpler:
1. instead of checking for duplicate column names in its own block,
reuse the original one that already did that;
2. instead of concatenating the list of columns from parent and the one
declared in the partition and scanning the result to (incorrectly)
propagate defaults and not-null constraints, just scan the latter
searching the former for a match, and merging sensibly. This works
because we know the list in the parent is already correct and there can
only be one parent.
This rewrite makes ColumnDef->is_from_parent unused, so it's removed
on branch master; on released branches, it's kept as an unused field in
order not to cause ABI incompatibilities.
This commit also adds a test case for creating partitions with
collations mismatching that on the parent table, something that is
closely related to the code being patched. No code change is introduced
though, since that'd be a behavior change that could break some (broken)
working applications.
Amit Langote wrote a less invasive fix for the original
NOT NULL/defaults bug, but while I kept the tests he added, I ended up
not using his original code. Ashutosh Bapat reviewed Amit's fix. Amit
reviewed mine.
Author: Álvaro Herrera, Amit Langote
Reviewed-by: Ashutosh Bapat, Amit Langote
Reported-by: Jürgen Strobel (bug #15212)
Discussion: https://postgr.es/m/152746742177.1291.9847032632907407358@wrigleys.postgresql.org
When a partition is created as part of a trigger processing, it is
possible that the partition which just gets created changes the
properties of the table the executor of the ongoing command relies on,
causing a subsequent crash. This has been found possible when for
example using a BEFORE INSERT which creates a new partition for a
partitioned table being inserted to.
Any attempt to do so is blocked when working on a partition, with
regression tests added for both CREATE TABLE PARTITION OF and ALTER
TABLE ATTACH PARTITION.
Reported-by: Dmitry Shalashov
Author: Amit Langote
Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/15437-3fe01ee66bd1bae1@postgresql.org
Backpatch-through: 10
Modifying the parse tree at execution time is, or at least ought to be,
verboten. It seems quite difficult to actually cause a crash this way
in v11 (although you can exhibit it pretty easily in HEAD by messing
with plan_cache_mode). Nonetheless, it's risky, so fix and back-patch.
Discussion: https://postgr.es/m/13789.1541359611@sss.pgh.pa.us
When creating partitioned indexes, the tablespace was not being saved
for the parent index. This meant that subsequently created partitions
would not use the right tablespace for their indexes.
ALTER INDEX SET TABLESPACE and ALTER INDEX ALL IN TABLESPACE raised
errors when tried; fix them too. This requires bespoke code for
ATExecCmd() that applies to the special case when the tablespace move is
just a catalog change.
Discussion: https://postgr.es/m/20181102003138.uxpaca6qfxzskepi@alvherre.pgsql
All existing uses can get this information more easily from the
relation descriptor, so the detour through the syscache is not
necessary.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Like for relations, switching this parameter is optimistic by turning it
on each time a partitioned index gains a partition. So seeing this
parameter set to true means that the partitioned index has or has had
partitions. The flag cannot be reset yet for partitioned indexes, which
is something not obvious anyway as partitioned relations exist to have
partitions.
This allows to track more conveniently partition trees for indexes,
which will come in use with an upcoming patch helping in listing
partition trees with an SQL-callable function.
Author: Amit Langote
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/80306490-b5fc-ea34-4427-f29c52156052@lab.ntt.co.jp
A bug introduced in 0d5f05cde0
considered the *previous* partition's triggers when deciding whether
multi-insert can be used. Rearrange the code so that the current
partition is considered.
Author: Ashutosh Sharma <ashu.coek88@gmail.com>
This allows the compiler / linker to mark affected pages as read-only.
There's other cases, but they're a bit more invasive, and should go
through some review. These are easy.
They were found with
objdump -j .data -t src/backend/postgres|awk '{print $4, $5, $6}'|sort -r|less
Discussion: https://postgr.es/m/20181015200754.7y7zfuzsoux2c4ya@alap3.anarazel.de
There was no code to handle foreign key constraints on partitioned
tables in the case of ALTER TABLE DETACH; and if you happened to ATTACH
a partition that already had an equivalent constraint, that one was
ignored and a new constraint was created. Adding this to the fact that
foreign key cloning reuses the constraint name on the partition instead
of generating a new name (as it probably should, to cater to SQL
standard rules about constraint naming within schemas), the result was a
pretty poor user experience -- the most visible failure was that just
detaching a partition and re-attaching it failed with an error such as
ERROR: duplicate key value violates unique constraint "pg_constraint_conrelid_contypid_conname_index"
DETAIL: Key (conrelid, contypid, conname)=(26702, 0, test_result_asset_id_fkey) already exists.
because it would try to create an identically-named constraint in the
partition. To make matters worse, if you tried to drop the constraint
in the now-independent partition, that would fail because the constraint
was still seen as dependent on the constraint in its former parent
partitioned table:
ERROR: cannot drop inherited constraint "test_result_asset_id_fkey" of relation "test_result_cbsystem_0001_0050_monthly_2018_09"
This fix attacks the problem from two angles: first, when the partition
is detached, the constraint is also marked as independent, so the drop
now works. Second, when the partition is re-attached, we scan existing
constraints searching for one matching the FK in the parent, and if one
exists, we link that one to the parent constraint. So we don't end up
with a duplicate -- and better yet, we don't need to scan the referenced
table to verify that the constraint holds.
To implement this I made a small change to previously planner-only
struct ForeignKeyCacheInfo to contain the constraint OID; also relcache
now maintains the list of FKs for partitioned tables too.
Backpatch to 11.
Reported-by: Michael Vitale (bug #15425)
Discussion: https://postgr.es/m/15425-2dbc9d2aa999f816@postgresql.org
It was previously a string setting that was converted into an enum by
custom code, but using the GUC enum facility seems much simpler and
doesn't change any functionality, except that
set transaction_isolation='default';
no longer works, but that was never documented and doesn't work with
any other transaction characteristics. (Note that this is not the
same as RESET or SET TO DEFAULT, which still work.)
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/457db615-e84c-4838-310e-43841eb806e5@iki.fi
Originally committed as 15bc038f (plus some follow-ups), this was
reverted in 28e07270 due to a problem discovered in parallel
workers. This new version corrects that problem by sending the
list of uncommitted enum values to parallel workers.
Here follows the original commit message describing the change:
To prevent possibly breaking indexes on enum columns, we must keep
uncommitted enum values from getting stored in tables, unless we
can be sure that any such column is new in the current transaction.
Formerly, we enforced this by disallowing ALTER TYPE ... ADD VALUE
from being executed at all in a transaction block, unless the target
enum type had been created in the current transaction. This patch
removes that restriction, and instead insists that an uncommitted enum
value can't be referenced unless it belongs to an enum type created
in the same transaction as the value. Per discussion, this should be
a bit less onerous. It does require each function that could possibly
return a new enum value to SQL operations to check this restriction,
but there aren't so many of those that this seems unmaintainable.
Author: Andrew Dunstan and Tom Lane, with parallel query fix by Thomas Munro
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/CAEepm%3D0Ei7g6PaNTbcmAh9tCRahQrk%3Dr5ZWLD-jr7hXweYX3yg%40mail.gmail.com
Discussion: https://postgr.es/m/4075.1459088427%40sss.pgh.pa.us
gcc 6.3 does not whine about this mistake I made in 39808e8868 but
evidently lots of other compilers do, according to Michael Paquier,
Peter Eisentraut, Arthur Zakirov, Tomas Vondra.
Discussion: too many to list
Error messages for creating a foreign key on a partitioned table using
ONLY or NOT VALID were wrong in mentioning the objects they worked on.
This commit adds on the way some regression tests missing for those
cases.
Author: Laurenz Albe
Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/c11c05810a9ed65e9b2c817a9ef442275a32fe80.camel@cybertec.at
Commit 2fbdf1b38b changed the order in which we inserted catalog rows
when creating partitions, so that we could remove an unsightly hack
required for untimely relcache invalidations. However, that commit only
changed the ordering for CREATE TABLE PARTITION OF, and left ALTER TABLE
ATTACH PARTITION unchanged, so the latter can be affected when catalog
invalidations occur, for instance when the partition key involves an SQL
function.
Reported-by: Rajkumar Raghuwanshi
Author: Amit Langote
Reviewed-by: Michaël Paquier
Discussion: https://postgr.es/m/CAKcux6=nTz9KSfTr_6Z2mpzLJ_09JN-rK6=dWic6gGyTSWueyQ@mail.gmail.com
Index DDL cascading on partitioned tables introduced a way for ALTER
TABLE to be called reentrantly. This caused an an important deficiency
in event trigger support to be exposed: on exiting the reentrant call,
the alter table state object was clobbered, causing a crash when the
outer alter table tries to finalize its processing. Fix the crash by
creating a stack of event trigger state objects. There are still ways
to cause things to misbehave (and probably other crashers) with more
elaborate tricks, but at least it now doesn't crash in the obvious
scenario.
Backpatch to 9.5, where DDL deparsing of event triggers was introduced.
Reported-by: Marco Slot
Authors: Michaël Paquier, Álvaro Herrera
Discussion: https://postgr.es/m/CANNhMLCpi+HQ7M36uPfGbJZEQLyTy7XvX=5EFkpR-b1bo0uJew@mail.gmail.com
This is for example used when attaching a partition to a partitioned
table which includes foreign keys, and in this case the constraint name
has been missing in the data cloned. This could lead to hard crashes,
as when validating the foreign key constraint, the constraint name is
always expected. Particularly, when using log_min_messages >= DEBUG1, a
log message would be generated with this unassigned constraint name,
leading to an assertion failure on HEAD.
While on it, rename a variable in ATExecAttachPartition which was
declared twice with the same name.
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/20181005042236.GG1629@paquier.xyz
Backpatch-through: 11
Instead of doing a lot of list_nth() accesses to es_range_table,
create a flattened pointer array during executor startup and index
into that to get at individual RangeTblEntrys.
This eliminates one source of O(N^2) behavior with lots of partitions.
(I'm not exactly convinced that it's the most important source, but
it's an easy one to fix.)
Amit Langote and David Rowley
Discussion: https://postgr.es/m/468c85d9-540e-66a2-1dde-fec2b741e688@lab.ntt.co.jp
Create an array estate->es_relations[] paralleling the es_range_table,
and store references to Relations (relcache entries) there, so that any
given RT entry is opened and closed just once per executor run. Scan
nodes typically still call ExecOpenScanRelation, but ExecCloseScanRelation
is no more; relation closing is now done centrally in ExecEndPlan.
This is slightly more complex than one would expect because of the
interactions with relcache references held in ResultRelInfo nodes.
The general convention is now that ResultRelInfo->ri_RelationDesc does
not represent a separate relcache reference and so does not need to be
explicitly closed; but there is an exception for ResultRelInfos in the
es_trig_target_relations list, which are manufactured by
ExecGetTriggerResultRel and have to be cleaned up by
ExecCleanUpTriggerState. (That much was true all along, but these
ResultRelInfos are now more different from others than they used to be.)
To allow the partition pruning logic to make use of es_relations[] rather
than having its own relcache references, adjust PartitionedRelPruneInfo
to store an RT index rather than a relation OID.
Amit Langote, reviewed by David Rowley and Jesper Pedersen,
some mods by me
Discussion: https://postgr.es/m/468c85d9-540e-66a2-1dde-fec2b741e688@lab.ntt.co.jp
When specified, this option allows VACUUM to skip the work on a relation
if there is a conflicting lock on it when trying to open it at the
beginning of its processing.
Similarly to autovacuum, this comes with a couple of limitations while
the relation is processed which can cause the process to still block:
- when opening the relation indexes.
- when acquiring row samples for table inheritance trees, partition trees
or certain types of foreign tables, and that a lock is taken on some
leaves of such trees.
Author: Nathan Bossart
Reviewed-by: Michael Paquier, Andres Freund, Masahiko Sawada
Discussion: https://postgr.es/m/9EF7EBE4-720D-4CF1-9D0E-4403D7E92990@amazon.com
Discussion: https://postgr.es/m/20171201160907.27110.74730@wrigleys.postgresql.org
I (Andres) was more than a bit hasty in committing 33001fd7a7
after last minute changes, leading to a number of problems (jit output
was only shown for JIT in parallel workers, and just EXPLAIN without
ANALYZE didn't work). Lukas luckily found these issues quickly.
Instead of combining instrumentation in in standard_ExecutorEnd(), do
so on demand in the new ExplainPrintJITSummary().
Also update a documentation example of the JIT output, changed in
52050ad8eb.
Author: Lukas Fittl, with minor changes by me
Discussion: https://postgr.es/m/CAP53PkxmgJht69pabxBXJBM+0oc6kf3KHMborLP7H2ouJ0CCtQ@mail.gmail.com
Backpatch: 11, where JIT compilation was introduced
It's inefficient to use a single slot for mapping between tuple
descriptors for multiple tuples, as previously done when using
ConvertPartitionTupleSlot(), as that means the slot's tuple descriptors
change for every tuple.
Previously we also, via ConvertPartitionTupleSlot(), built new tuples
after the mapping even in cases where we, immediately afterwards,
access individual columns again.
Refactor the code so one slot, on demand, is used for each
partition. That avoids having to change the descriptor (and allows to
use the more efficient "fixed" tuple slots). Then use slot->slot
mapping, to avoid unnecessarily forming a tuple.
As the naming between the tuple and slot mapping functions wasn't
consistent, rename them to execute_attr_map_{tuple,slot}. It's likely
that we'll also rename convert_tuples_by_* to denote that these
functions "only" build a map, but that's left for later.
Author: Amit Khandekar and Amit Langote, editorialized by me
Reviewed-By: Amit Langote, Amit Khandekar, Andres Freund
Discussion:
https://postgr.es/m/CAJ3gD9fR0wRNeAE8VqffNTyONS_UfFPRpqxhnD9Q42vZB+Jvpg@mail.gmail.comhttps://postgr.es/m/e4f9d743-cd4b-efb0-7574-da21d86a7f36%40lab.ntt.co.jp
Backpatch: -
VACUUM and ANALYZE share similar logic when it comes to opening a
relation to work on in terms of how the relation is opened, in which
order locks are tried and how logs should be generated when something
does not work as expected.
This commit refactors things so as both use the same code path to handle
the way a relation is opened, so as the integration of new options
becomes easier.
Author: Michael Paquier
Reviewed-by: Nathan Bossart
Discussion: https://postgr.es/m/20180927075152.GT1659@paquier.xyz
If the column being modified is referenced by a foreign key constraint
of another table, ALTER TABLE would open the other table (to re-parse
the constraint's definition) without having first obtained a lock on it.
This was evidently intentional, but that doesn't mean it's really safe.
It's especially not safe in 9.3, which pre-dates use of MVCC scans for
catalog reads, but even in current releases it doesn't seem like a good
idea.
We know we'll need AccessExclusiveLock shortly to drop the obsoleted
constraint, so just get that a little sooner to close the hole.
Per testing with a patch that complains if we open a relation without
holding any lock on it. I don't plan to back-patch that patch, but we
should close the holes it identifies in all supported branches.
Discussion: https://postgr.es/m/2038.1538335244@sss.pgh.pa.us
Add RangeTblEntry.rellockmode, which records the appropriate lock mode for
each RTE_RELATION rangetable entry (either AccessShareLock, RowShareLock,
or RowExclusiveLock depending on the RTE's role in the query).
This patch creates the field and makes all creators of RTE nodes fill it
in reasonably, but for the moment nothing much is done with it. The plan
is to replace assorted post-parser logic that re-determines the right
lockmode to use with simple uses of rte->rellockmode. For now, just add
Asserts in each of those places that the rellockmode matches what they are
computing today. (In some cases the match isn't perfect, so the Asserts
are weaker than you might expect; but this seems OK, as per discussion.)
This passes check-world for me, but it seems worth pushing in this state
to see if the buildfarm finds any problems in cases I failed to test.
catversion bump due to change of stored rules.
Amit Langote, reviewed by David Rowley and Jesper Pedersen,
and whacked around a bit more by me
Discussion: https://postgr.es/m/468c85d9-540e-66a2-1dde-fec2b741e688@lab.ntt.co.jp
When a table ownership is changed, we must apply that also to any owned
sequences. (Otherwise, it would result in a situation that cannot be
restored, because linked sequences must have the same owner as the
table.) But this was previously only applied to regular tables and
materialized views. But it should also apply to at least foreign
tables. This patch removes the relkind check altogether, because it
doesn't save very much and just introduces the possibility of similar
omissions.
Bug: #15238
Reported-by: Christoph Berg <christoph.berg@credativ.de>
Upcoming changes introduce further types of tuple table slots, in
preparation of making table storage pluggable. New storage methods
will have different representation of tuples, therefore the slot
accessor should refer explicitly to heap tuples.
Instead of just renaming the functions, split it into one function
that accepts heap tuples not residing in buffers, and one accepting
ones in buffers. Previously one function was used for both, but that
was a bit awkward already, and splitting will allow us to represent
slot types for tuples in buffers and normal memory separately.
This is split out from the patch introducing abstract slots, as this
largely consists out of mechanical changes.
Author: Ashutosh Bapat
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
Previously, when using parallel query, EXPLAIN (ANALYZE)'s JIT
compilation timings did not include the overhead from doing so on the
workers. Fix that.
We do so by simply aggregating the cost of doing JIT compilation on
workers and the leader together. Arguably that's not quite accurate,
because the total time spend doing so is spent in parallel - but it's
hard to do much better. For additional detail, when VERBOSE is
specified, the stats for workers are displayed separately.
Author: Amit Khandekar and Andres Freund
Discussion: https://postgr.es/m/CAJ3gD9eLrz51RK_gTkod+71iDcjpB_N8eC6vU2AW-VicsAERpQ@mail.gmail.com
Backpatch: 11-
A discussion about also reporting JIT compilation overhead on workers
brought unhappiness with the verbosity of the current explain format
to light. Make the text format more dense, and restructure the
structured output to mirror that more closely.
As we're re-jiggering the output format anyway: The denser format
allows us to report all flags for JIT compilation (now also reporting
PGJIT_EXPR and PGJIT_DEFORM), and report the total time in addition to
the individual times.
Per complaint from Tom Lane.
Author: Andres Freund
Discussion: https://postgr.es/m/27812.1537221015@sss.pgh.pa.us
Backpatch: 11-, where JIT compilation was introduced
Ensure that triggers get properly filled in tuples for the OLD value.
Also fix the logic of detecting missing null values. The previous logic
failed to detect a missing null column before the first missing column
with a default. Fixing this has simplified the logic a bit.
Regression tests are added to test changes. This should ensure better
coverage of expand_tuple().
Original bug reports, and some code and test scripts from Tomas Vondra
Backpatch to release 11.
When ALTER TABLE ... SET DATA TYPE affects a column referenced by
constraints and indexes, it drop those constraints and indexes and
recreates them afterwards, so that the definitions match the new data
type. The original code did this by dropping one object at a time
(commit 077db40fa1 of May 2004), which worked fine because the
dependencies between the objects were pretty straightforward, and
ordering the objects in a specific way was enough to make this work.
However, when there are foreign key constraints in partitioned tables,
the dependencies are no longer so straightforward, and we were getting
errors when attempted:
ERROR: cache lookup failed for constraint 16398
This can be fixed by doing all the drops in one pass instead, using
performMultipleDeletions (introduced by df18c51f29 of Aug 2006). With
this change we can also remove the code to carefully order the list of
objects to be deleted.
Reported-by: Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAKcux6nWS_m+s=1Udk_U9B+QY7pA-Ac58qR5BdUfOyrwnWHDew@mail.gmail.com
A log message was being generated when log_min_duration is reached for
autovacuum on a given relation to indicate if it was an aggressive run,
and missed the point of mentioning if it is doing an anti-wrapround
run. The log message generated is improved so as one, both or no extra
details are added depending on the option set.
Author: Sergei Kornilov
Reviewed-by: Masahiko Sawada, Michael Paquier
Discussion: https://postgr.es/m/11587951532155118@sas1-19a94364928d.qloud-c.yandex.net
An extra argument for the filename defining the extension script
location was present, aimed at being used for error reporting, but has
never been used. This was around since extensions have been added in
d9572c4.
Author: Yugo Nagata
Reviewed-by: Tatsuo Ishii
Discussion: https://postgr.es/m/20180907180504.1ff19e1675bb44a67e9c7ab1@sraoss.co.jp
In the original code, we were storing the pg_inherits row for a
partitioned table too early: enough that we had a hack for relcache to
avoid falling flat on its face while reading such a partial entry. If
we finish the pg_class creation first and *then* store the pg_inherits
entry, we don't need that hack.
Also recognize that pg_class.relpartbound is not marked NOT NULL and
therefore it's entirely possible to read null values, so having only
Assert() protection isn't enough. Change those to if/elog tests
instead. This qualifies as a robustness fix, so backpatch to pg11.
In passing, remove one access that wasn't actually needed, and reword
one message to be like all the others that check for the same thing.
Reviewed-by: Amit Langote
Discussion: https://postgr.es/m/20180903213916.hh6wasnrdg6xv2ud@alvherre.pgsql
It's been true for a long time that we expect names of table and domain
constraints to be unique among the constraints of that table or domain.
However, the enforcement of that has been pretty haphazard, and it missed
some corner cases such as creating a CHECK constraint and then an index
constraint of the same name (as per recent report from André Hänsel).
Also, due to the lack of an actual unique index enforcing this, duplicates
could be created through race conditions.
Moreover, the code that searches pg_constraint has been quite inconsistent
about how to handle duplicate names if one did occur: some places checked
and threw errors if there was more than one match, while others just
processed the first match they came to.
To fix, create a unique index on (conrelid, contypid, conname). Since
either conrelid or contypid is zero, this will separately enforce
uniqueness of constraint names among constraints of any one table and any
one domain. (If we ever implement SQL assertions, and put them into this
catalog, more thought might be needed. But it'd be at least as reasonable
to put them into a new catalog; having overloaded this one catalog with
two kinds of constraints was a mistake already IMO.) This index can replace
the existing non-unique index on conrelid, though we need to keep the one
on contypid for query performance reasons.
Having done that, we can simplify the logic in various places that either
coped with duplicates or neglected to, as well as potentially improve
lookup performance when searching for a constraint by name.
Also, as per our usual practice, install a preliminary check so that you
get something more friendly than a unique-index violation report in the
case complained of by André. And teach ChooseIndexName to avoid choosing
autogenerated names that would draw such a failure.
While it's not possible to make such a change in the back branches,
it doesn't seem quite too late to put this into v11, so do so.
Discussion: https://postgr.es/m/0c1001d4428f$0942b430$1bc81c90$@webkr.de
There's a project policy against using plain "char buf[BLCKSZ]" local
or static variables as page buffers; preferred style is to palloc or
malloc each buffer to ensure it is MAXALIGN'd. However, that policy's
been ignored in an increasing number of places. We've apparently got
away with it so far, probably because (a) relatively few people use
platforms on which misalignment causes core dumps and/or (b) the
variables chance to be sufficiently aligned anyway. But this is not
something to rely on. Moreover, even if we don't get a core dump,
we might be paying a lot of cycles for misaligned accesses.
To fix, invent new union types PGAlignedBlock and PGAlignedXLogBlock
that the compiler must allocate with sufficient alignment, and use
those in place of plain char arrays.
I used these types even for variables where there's no risk of a
misaligned access, since ensuring proper alignment should make
kernel data transfers faster. I also changed some places where
we had been palloc'ing short-lived buffers, for coding style
uniformity and to save palloc/pfree overhead.
Since this seems to be a live portability hazard (despite the lack
of field reports), back-patch to all supported versions.
Patch by me; thanks to Michael Paquier for review.
Discussion: https://postgr.es/m/1535618100.1286.3.camel@credativ.de
Add support for error position reporting for the expressions contained
in defaults and check constraint definitions. This currently works only
for CREATE TABLE, not ALTER TABLE, because the latter is not set up to
pass around the original query string.
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
A caller of VACUUM can perform early lookup obtention which can cause
other sessions to block on the request done, causing potentially DOS
attacks as even a non-privileged user can attempt a vacuum fill of a
critical catalog table to block even all incoming connection attempts.
Contrary to TRUNCATE, a client could attempt a system-wide VACUUM after
building the list of relations to VACUUM, which can cause vacuum_rel()
or analyze_rel() to try to lock the relation but the operation would
just block. When the client specifies a list of relations and the
relation needs to be skipped, ownership checks are done when building
the list of relations to work on, preventing a later lock attempt.
vacuum_rel() already had the sanity checks needed, except that those
were applied too late. This commit refactors the code so as relation
skips are checked beforehand, making it safer to avoid too early locks,
for both manual VACUUM with and without a list of relations specified.
An isolation test is added emulating the fact that early locks do not
happen anymore, issuing a WARNING message earlier if the user calling
VACUUM is not a relation owner.
When a partitioned table is listed in a manual VACUUM or ANALYZE
command, its full list of partitions is fetched, all partitions get
added to the list to work on, and then each one of them is processed one
by one, with ownership checks happening at the later phase of
vacuum_rel() or analyze_rel(). Trying to do early ownership checks for
each partition is proving to be tedious as this would result in deadlock
risks with lock upgrades, and skipping all partitions if the listed
partitioned table is not owned would result in a behavior change
compared to how Postgres 10 has implemented vacuum for partitioned
tables. The original problem reported related to early lock queue for
critical relations is fixed anyway, so priority is given to avoiding a
backward-incompatible behavior.
Reported-by: Lloyd Albin, Jeremy Schneider
Author: Michael Paquier
Reviewed by: Nathan Bossart, Kyotaro Horiguchi
Discussion: https://postgr.es/m/152512087100.19803.12733865831237526317@wrigleys.postgresql.org
Discussion: https://postgr.es/m/20180812222142.GA6097@paquier.xyz
Since procedures are now a different thing from functions, change the
CREATE OPERATOR syntax to use FUNCTION in the clause that specifies the
function. PROCEDURE is still accepted for compatibility.
Reported-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
Historically, the term procedure was used as a synonym for function in
Postgres/PostgreSQL. Now we have procedures as separate objects from
functions, so we need to clean up the documentation to not mix those
terms.
In particular, mentions of "trigger procedures" are changed to "trigger
functions", and access method "support procedures" are changed to
"support functions". (The latter already used FUNCTION in the SQL
syntax anyway.) Also, the terminology in the SPI chapter has been
cleaned up.
A few tests, examples, and code comments are also adjusted to be
consistent with documentation changes, but not everything.
Reported-by: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
While monitoring the code, a couple of issues related to string
translation has showed up:
- Some routines for auto-updatable views return an error string, which
sometimes missed the shot. A comment regarding string translation is
added for each routine to help with future features.
- GSSAPI authentication missed two translations.
- vacuumdb handles non-translated strings.
- GetConfigOptionByNum should translate strings. This part is not
back-patched as after a minor upgrade this could be surprising for
users.
Reported-by: Kyotaro Horiguchi
Author: Kyotaro Horiguchi
Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/20180810.152131.31921918.horiguchi.kyotaro@lab.ntt.co.jp
Backpatch-through: 9.3
InsertPgAttributeTuple() is the interface between in-memory tuple
descriptors and on-disk pg_attribute, so it makes sense to give it the
job of resetting attcacheoff. This avoids having all the callers having
to do so.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
A caller of TRUNCATE could previously queue for an access exclusive lock
on a relation it may not have permission to truncate, potentially
interfering with users authorized to work on it. This can be very
intrusive depending on the lock attempted to be taken. For example,
pg_authid could be blocked, preventing any authentication attempt to
happen on a PostgreSQL instance.
This commit fixes the case of TRUNCATE so as RangeVarGetRelidExtended is
used with a callback doing the necessary ACL checks at an earlier stage,
avoiding lock queuing issues, so as an immediate failure happens for
unprivileged users instead of waiting on a lock that would not be
taken.
This is rather similar to the type of work done in cbe24a6 for CLUSTER,
and the code of TRUNCATE is this time refactored so as there is no
user-facing changes. As the commit for CLUSTER, no back-patch is done.
Reported-by: Lloyd Albin, Jeremy Schneider
Author: Michael Paquier
Reviewed by: Nathan Bossart, Kyotaro Horiguchi
Discussion: https://postgr.es/m/152512087100.19803.12733865831237526317@wrigleys.postgresql.org
Discussion: https://postgr.es/m/20180806165816.GA19883@paquier.xyz
A database owner running a database-level REINDEX has the possibility to
also do the operation on shared system catalogs without being an owner
of them, which allows him to block resources it should not have access
to. The same goes for a schema owner. For example, PostgreSQL would go
unresponsive and even block authentication if a lock is waited for
pg_authid. This commit makes sure that a user running a REINDEX SYSTEM,
DATABASE or SCHEMA only works on the following relations:
- The user is a superuser
- The user is the table owner
- The user is the database/schema owner, only if the relation worked on
is not shared.
Robert has worded most the documentation changes, and I have coded the
core part.
Reported-by: Lloyd Albin, Jeremy Schneider
Author: Michael Paquier, Robert Haas
Reviewed by: Nathan Bossart, Kyotaro Horiguchi
Discussion: https://postgr.es/m/152512087100.19803.12733865831237526317@wrigleys.postgresql.org
Discussion: https://postgr.es/m/20180805211059.GA2185@paquier.xyz
Backpatch-through: 11- as the current behavior has been around for a
very long time and could be disruptive for already released branches.
CreateUserMapping has a recordDependencyOnCurrentExtension call that's
been there since extensions were introduced (very possibly my fault).
However, there's no support anywhere else for user mappings as members
of extensions, nor are they listed as a possible member object type in
the documentation. Nor does it really seem like a good idea for user
mappings to belong to extensions when roles don't. Hence, remove the
bogus call.
(As we saw in bug #15310, the lack of any pg_dump support for this case
ensures that any such membership record would silently disappear during
pg_upgrade. So there's probably no need for us to do anything else
about cleaning up after this mistake.)
Discussion: https://postgr.es/m/27952.1533667213@sss.pgh.pa.us
CopyFrom allows multi-inserts to be used for non-partitioned tables, but
this was disabled for partitioned tables. The reason for this appeared
to be that the tuple may not belong to the same partition as the
previous tuple did. Not allowing multi-inserts here greatly slowed down
imports into partitioned tables. These could take twice as long as a
copy to an equivalent non-partitioned table. It seems wise to do
something about this, so this change allows the multi-inserts by
flushing the so-far inserted tuples to the partition when the next tuple
does not belong to the same partition, or when the buffer fills. This
improves performance when the next tuple in the stream commonly belongs
to the same partition as the previous tuple.
In cases where the target partition changes on every tuple, using
multi-inserts slightly slows the performance. To get around this we
track the average size of the batches that have been inserted and
adaptively enable or disable multi-inserts based on the size of the
batch. Some testing was done and the regression only seems to exist
when the average size of the insert batch is close to 1, so let's just
enable multi-inserts when the average size is at least 1.3. More
performance testing might reveal a better number for, this, but since
the slowdown was only 1-2% it does not seem critical enough to spend too
much time calculating it. In any case it may depend on other factors
rather than just the size of the batch.
Allowing multi-inserts for partitions required a bit of work around the
per-tuple memory contexts as we must flush the tuples when the next
tuple does not belong the same partition. In which case there is no
good time to reset the per-tuple context, as we've already built the new
tuple by this time. In order to work around this we maintain two
per-tuple contexts and just switch between them every time the partition
changes and reset the old one. This does mean that the first of each
batch of tuples is not allocated in the same memory context as the
others, but that does not matter since we only reset the context once
the previous batch has been inserted.
Author: David Rowley <david.rowley@2ndquadrant.com>
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
The recheck option became a no-op as ClusterOption failed to set proper
values for each element. There was a second code path where local
options got overwritten.
Both issues have been spotted by Coverity.
This extends cluster_rel() in such a way that more options can be added
in the future, which will reduce the amount of chunk code for an
upcoming SKIP_LOCKED aimed for VACUUM. As VACUUM FULL is a different
flavor of CLUSTER, we want to make that extensible to ease integration.
This only reworks the API and its callers, without providing anything
user-facing. Two options are present now: verbose mode and relation
recheck when doing the cluster command work across multiple
transactions. This could be used as well as a base to extend the
grammar of CLUSTER later on.
Author: Michael Paquier
Reviewed-by: Nathan Bossart
Discussion: https://postgr.es/m/20180723031058.GE2854@paquier.xyz
transformPartitionSpec rejected duplicate simple partition columns
(e.g., "PARTITION BY RANGE (x,x)") but paid no attention to expression
columns, resulting in inconsistent behavior. Worse, cases like
"PARTITION BY RANGE (x,(x))") were accepted but would then result in
dump/reload failures, since the expression (x) would get simplified
to a plain column later.
There seems no better reason for this restriction than there was for
the one against duplicate included index columns (cf commit 701fd0bbc),
so let's just remove it.
Back-patch to v10 where this code was added.
Report and patch by Yugo Nagata.
Discussion: https://postgr.es/m/20180712165939.36b12aff.nagata@sraoss.co.jp
The initial version of the included-index-column feature stated that
included columns couldn't be the same as any key column of the index.
While it'd be pretty silly to do that, since the included column would be
entirely redundant, we've never prohibited redundant index columns before
so it's not very consistent to do so here. Moreover, the prohibition
was itself badly implemented, so that it failed to reject columns that
were effectively identical but not spelled quite alike, as reported by
Aditya Toshniwal.
(Moreover, it's not hard to imagine that for some non-btree index types,
such cases would be non-silly anyhow: the index might use a lossy
representation for key columns but be able to support retrieval of the
original form of included columns.)
Hence, let's just drop the prohibition.
In passing, do some copy-editing on the documentation for the
included-column feature.
Yugo Nagata; documentation and test corrections by me
Discussion: https://postgr.es/m/CAM9w-_mhBCys4fQNfaiQKTRrVWtoFrZ-wXmDuE9Nj5y-Y7aDKQ@mail.gmail.com
A collection of typos I happened to spot while reading code, as well as
grepping for common mistakes.
Backpatch to all supported versions, as applicable, to avoid conflicts
when backporting other commits in the future.
The existing error message was complaining that the column is not an
expression, which is not correct. Introduce a suitable wording
variation and a test.
Co-authored-by: Yugo Nagata <nagata@sraoss.co.jp>
Discussion: https://postgr.es/m/20180628182803.e4632d5a.nagata@sraoss.co.jp
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Starting and aborting transactions in security definer procedures
doesn't work. StartTransaction() insists that the security context
stack is empty, so this would currently cause a crash, and
AbortTransaction() resets it. This could be made to work by
reorganizing the code, but right now we just prohibit it.
Reported-by: amul sul <sulamul@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAAJ_b96Gupt_LFL7uNyy3c50-wbhA68NUjiK5%3DrF6_w%3Dpq_T%3DQ%40mail.gmail.com
When truncating a table that is referenced by foreign keys in
partitioned tables, the check to ensure the referencing table are also
truncated spuriously failed. This is because it was relying on
relhastriggers as a proxy for the table having FKs, and that's wrong for
partitioned tables. Fix it to consider such tables separately. There
may be a better way ... but this code is pretty inefficient already.
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Michael Paquiër <michael@paquier.xyz>
Discussion: https://postgr.es/m/20180711000624.zmeizicibxeehhsg@alvherre.pgsql
An update that causes the tuple to be moved to a different partition was
missing out on re-constructing the to-be-updated tuple, based on the latest
tuple in the update chain. Instead, it's simply deleting the latest tuple
and inserting a new tuple in the new partition based on the old tuple.
Commit 2f17844104 didn't consider this case, so some of the updates were
getting lost.
In passing, change the argument order for output parameter in ExecDelete
and add some commentary about it.
Reported-by: Pavan Deolasee
Author: Amit Khandekar, with minor changes by me
Reviewed-by: Dilip Kumar, Amit Kapila and Alvaro Herrera
Backpatch-through: 11
Discussion: https://postgr.es/m/CAJ3gD9fRbEzDqdeDq1jxqZUb47kJn+tQ7=Bcgjc8quqKsDViKQ@mail.gmail.com
When it comes to SELECT ... FOR or LOCK, NOWAIT means to not wait for
something to happen, and issue an error. SKIP LOCKED means to not wait
for something to happen but to move on without issuing an error. The
internal option of autovacuum and autoanalyze mentioned above, used only
when wraparound is not involved was named NOWAIT, but behaves like SKIP
LOCKED which is confusing.
Author: Nathan Bossart
Discussion: https://postgr.es/m/20180307050345.GA3095@paquier.xyz
The code path where the assertion is added helps to check that
autovacuum always includes a relation OID when doing a vacuum on it.
Extracted from a larger patch set to add support for SKIP LOCKED with
manual VACUUM commands.
Author: Nathan Bossart
Discussion: https://postgr.es/m/9EF7EBE4-720D-4CF1-9D0E-4403D7E92990@amazon.com
Two out of three code paths were mapping column numbers correctly if a
partition had different column numbers than parent table, but the most
commonly used one (recursing in CREATE INDEX to a new index on a
partition) failed to map attribute numbers in expressions. Oddly
enough, attnums in WHERE clauses are already handled correctly
everywhere.
Reported-by: Amit Langote
Author: Amit Langote
Discussion: https://postgr.es/m/dce1fda4-e0f0-94c9-6abb-f5956a98c057@lab.ntt.co.jp
Reviewed-by: Álvaro Herrera
Since their introduction, partition trees have been a bit lossy
regarding temporary relations. Inheritance trees respect the following
patterns:
1) a child relation can be temporary if the parent is permanent.
2) a child relation can be temporary if the parent is temporary.
3) a child relation cannot be permanent if the parent is temporary.
4) The use of temporary relations also imply that when both parent and
child need to be from the same sessions.
Partitions share many similar patterns with inheritance, however the
handling of the partition bounds make the situation a bit tricky for
case 1) as the partition code bases a lot of its lookup code upon
PartitionDesc which does not really look after relpersistence. This
causes for example a temporary partition created by session A to be
visible by another session B, preventing this session B to create an
extra partition which overlaps with the temporary one created by A with
a non-intuitive error message. There could be use-cases where mixing
permanent partitioned tables with temporary partitions make sense, but
that would be a new feature. Partitions respect 2), 3) and 4) already.
It is a bit depressing to see those error checks happening in
MergeAttributes() whose purpose is different, but that's left as future
refactoring work.
Back-patch down to 10, which is where partitioning has been introduced,
except that default partitions do not apply there. Documentation also
includes limitations related to the use of temporary tables with
partition trees.
Reported-by: David Rowley
Author: Amit Langote, Michael Paquier
Reviewed-by: Ashutosh Bapat, Amit Langote, Michael Paquier
Discussion: https://postgr.es/m/CAKJS1f94Ojk0og9GMkRHGt8wHTW=ijq5KzJKuoBoqWLwSVwGmw@mail.gmail.com
It might be impossible for this to cause a problem in non-debug builds,
since there'd be no opportunity for the relcache entry to get recycled
before the fetch. It blows up nicely with -DRELCACHE_FORCE_RELEASE plus
valgrind, though.
Evidently introduced by careless refactoring in commit f0e44751d.
Back-patch accordingly.
Discussion: https://postgr.es/m/27543.1528758304@sss.pgh.pa.us
Starting with commit f0e44751d7, ExecConstraints was in charge of
running the partition constraint; commit 19c47e7c82 modified that so
that caller could request to skip that checking depending on some
conditions, but that commit and 15ce775faa together introduced a small
bug there which caused ExecInsert to request skipping the constraint
check but have this not be honored -- in effect doing the check twice.
This could have been fixed in a very small patch, but on further
analysis of the involved function and its callsites, it turns out to be
simpler to give the responsibility of checking the partition constraint
fully to the caller, and return ExecConstraints to its original
(pre-partitioning) shape where it only checked tuple descriptor-related
constraints. Each caller must do partition constraint checking on its
own schedule, which is more convenient after commit 2f17844104 anyway.
Reported-by: David Rowley
Author: David Rowley, Álvaro Herrera
Reviewed-by: Amit Langote, Amit Khandekar, Simon Riggs
Discussion: https://postgr.es/m/CAKJS1f8w8+awsxgea8wt7_UX8qzOQ=Tm1LD+U1fHqBAkXxkW2w@mail.gmail.com
Because the code for the HEADER option skips a line when this counter
is zero, a very long COPY FROM WITH HEADER operation would drop a line
every 2^32 lines. A lesser but still unfortunate problem is that errors
would show a wrong input line number for errors occurring beyond the
2^31'st input line. While such large input streams seemed impractical
when this code was first written, they're not any more. Widening the
counter (and some associated variables) to uint64 should be enough to
prevent problems for the foreseeable future.
David Rowley
Discussion: https://postgr.es/m/CAKJS1f88yh-6wwEfO6QLEEvH3BEugOq2QX1TOja0vCauoynmOQ@mail.gmail.com
Recent gcc can warn about switch-case fall throughs that are not
explicitly labeled as intentional. This seems like a good thing,
so clean up the warnings exposed thereby by labeling all such
cases with comments that gcc will recognize.
In files that already had one or more suitable comments, I generally
matched the existing style of those. Otherwise I went with
/* FALLTHROUGH */, which is one of the spellings approved at the
more-restrictive-than-default level -Wimplicit-fallthrough=4.
(At the default level you can also spell it /* FALL ?THRU */,
and it's not picky about case. What you can't do is include
additional text in the same comment, so some existing comments
containing versions of this aren't good enough.)
Testing with gcc 8.0.1 (Fedora 28's current version), I found that
I also had to put explicit "break"s after elog(ERROR) or ereport(ERROR);
apparently, for this purpose gcc doesn't recognize that those don't
return. That seems like possibly a gcc bug, but it's fine because
in most places we did that anyway; so this amounts to a visit from the
style police.
Discussion: https://postgr.es/m/15083.1525207729@sss.pgh.pa.us
In commit f0e4475, GetIndexOpClass was renamed to ResolveOpClass, but
the comment in typecmds.c didn't get the memo.
In objectaddress.c, missing 'of' in a comment.
Both noticed by Vik Fearing, patch is mine though.
EventTriggerTableRewrite crashed if there were table_rewrite triggers
present, but there had not been when the calling command started.
EventTriggerDDLCommandEnd called ddl_command_end triggers if present,
even if there had been no such triggers when the calling command started,
which would lead to a failure in pg_event_trigger_ddl_commands.
In both cases, fix by doing nothing; it's better to wait till the next
command when things will be properly initialized.
In passing, remove an elog(DEBUG1) call that might have seemed interesting
four years ago but surely isn't today.
We found this because of intermittent failures in the buildfarm. Thanks
to Alvaro Herrera and Andrew Gierth for analysis.
Back-patch to 9.5; some of this code exists before that, but the specific
hazards we need to guard against don't.
Discussion: https://postgr.es/m/5767.1523995174@sss.pgh.pa.us
Commit 54eff5311 did not account for the possibility that we'd have
a transaction snapshot due to default_transaction_isolation being
set high enough to require one. The transaction snapshot is enough
to hold back our advertised xmin and thus risk deadlock anyway.
The only way to get rid of that snap is to start a new transaction,
so let's do that instead. Also throw in an assert checking that we
really have gotten to a state where no xmin is being advertised.
Back-patch to 9.4, like the previous commit.
Discussion: https://postgr.es/m/CAMkU=1ztk3TpQdcUNbxq93pc80FrXUjpDWLGMeVBDx71GHNwZQ@mail.gmail.com
We need to call expand_function_arguments() to expand named and default
arguments.
In PL/pgSQL, we also need to deal with named and default INOUT arguments
when receiving the output values into variables.
Author: Pavel Stehule <pavel.stehule@gmail.com>
- Explicitly forbids opclass, collation and indoptions (like DESC/ASC etc) for
including columns. Throw an error if user points that.
- Truncated storage arrays for such attributes to store only key atrributes,
added assertion checks.
- Do not check opfamily and collation for including columns in
CompareIndexInfo()
Discussion: https://www.postgresql.org/message-id/5ee72852-3c4e-ee35-e2ed-c1d053d45c08@sigaev.ru
This reverts commits d204ef6377,
83454e3c2b and a few more commits thereafter
(complete list at the end) related to MERGE feature.
While the feature was fully functional, with sufficient test coverage and
necessary documentation, it was felt that some parts of the executor and
parse-analyzer can use a different design and it wasn't possible to do that in
the available time. So it was decided to revert the patch for PG11 and retry
again in the future.
Thanks again to all reviewers and bug reporters.
List of commits reverted, in reverse chronological order:
f1464c5380 Improve parse representation for MERGE
ddb4158579 MERGE syntax diagram correction
530e69e59b Allow cpluspluscheck to pass by renaming variable
01b88b4df5 MERGE minor errata
3af7b2b0d4 MERGE fix variable warning in non-assert builds
a5d86181ec MERGE INSERT allows only one VALUES clause
4b2d44031f MERGE post-commit review
4923550c20 Tab completion for MERGE
aa3faa3c7a WITH support in MERGE
83454e3c2b New files for MERGE
d204ef6377 MERGE SQL Command following SQL:2016
Author: Pavan Deolasee
Reviewed-by: Michael Paquier
Oversight in commit 8b08f7d4820f: pg_class.relispartition was not
being set for index partitions, which is a bit odd, and was also causing
the code to unnecessarily call has_superclass() when simply checking the
flag was enough.
Author: Álvaro Herrera
Reported-by: Amit Langote
Discussion: https://postgr.es/m/12085bc4-0bc6-0f3a-4c43-57fe0681772b@lab.ntt.co.jp
If the table being attached contained values that contradict the default
partition's partition constraint, it would fail to complain, because
CommandCounterIncrement changes in 4dba331cb3 coupled with some bogus
coding in the existing ValidatePartitionConstraints prevented the
partition constraint from being validated after all -- or rather, it
caused to constraint to become an empty one, always succeeding.
Fix by not re-reading the OID of the default partition in
ATExecAttachPartition. To forestall similar problems, revise the
existing code:
* rename routine from ValidatePartitionConstraints() to
QueuePartitionConstraintValidation, to better represent what it
actually does.
* add an Assert() to make sure that when queueing a constraint for a
partition we're not overwriting a constraint previously queued.
* add an Assert() that we don't try to invoke the special-purpose
validation of the default partition when attaching the default
partition itself.
While at it, change some loops to obtain partition OIDs from
partdesc->oids rather than find_all_inheritors; reduce the lock level
of partitions being scanned from AccessExclusiveLock to ShareLock;
rewrite QueuePartitionConstraintValidation in a recursive fashion rather
than repetitive.
Author: Álvaro Herrera. Tests written by Amit Langote
Reported-by: Rushabh Lathia
Diagnosed-by: Kyotaro HORIGUCHI, who also provided the initial fix.
Reviewed-by: Kyotaro HORIGUCHI, Amit Langote, Jeevan Ladhe
Discussion: https://postgr.es/m/CAGPqQf0W+v-Ci_qNV_5R3A=Z9LsK4+jO7LzgddRncpp_rrnJqQ@mail.gmail.com
The bug is caused due to the original IndexStmt that DefineIndex receives
being overwritten when processing the INCLUDE columns. Use separate list of
index params to propagate to child tables. Add tests covering this case.
Amit Langote and Alexander Korotkov.
The HeapFetches counter was using a simple value in IndexOnlyScanState,
which fails to propagate values from parallel workers; so the counts are
wrong when IndexOnlyScan runs in parallel. Move it to Instrumentation,
like all the other counters.
While at it, change INSERT ON CONFLICT conflicting tuple counter to use
the new ntuples2 instead of nfiltered2, which is a blatant misuse.
Discussion: https://postgr.es/m/20180409215851.idwc75ct2bzi6tea@alvherre.pgsql
In commit 9c0a0de4c, I'd failed to notice that catalog/catalog.h
should also be considered a frontend-unsafe header, because it includes
(and needs) the full form of pg_class.h, not to mention relcache.h.
However, various frontend code was depending on it to get
TABLESPACE_VERSION_DIRECTORY, so refactoring of some sort is called for.
The cleanest answer seems to be to move TABLESPACE_VERSION_DIRECTORY,
as well as the OIDCHARS symbol, to common/relpath.h. Do that, and mop up
inclusions as necessary. (I found that quite a few current users of
catalog/catalog.h don't seem to need it at all anymore, apparently as a
result of the refactorings that created common/relpath.[hc]. And
initdb.c needed it only as a route to pg_class_d.h.)
Discussion: https://postgr.es/m/6629.1523294509@sss.pgh.pa.us
CheckIndexCompatible() misused ComputeIndexAttrs() by not bothering
to fill ii_NumIndexAttrs and ii_NumIndexKeyAttrs in the passed
IndexInfo. Omission of ii_NumIndexAttrs was previously unimportant,
but now this matters because ComputeIndexAttrs depends on
ii_NumIndexKeyAttrs to decide how many columns it needs to report on.
(BTW, the fact that this oversight wasn't detected earlier implies
that we have no regression test verifying whether CheckIndexCompatible
ever succeeds. Bad dog. Not the job of this patch to fix it, though.)
Also, change the API of ComputeIndexAttrs so that it fills the opclass
output array for all column positions, as it does for the options output
array; positions for non-key index columns are filled with zeroes.
This isn't directly fixing any bug, but it seems like a good idea.
Per valgrind failure reports from buildfarm.
Alexander Korotkov, tweaked a bit by me
Discussion: https://postgr.es/m/CAPpHfduWrysrT-qAhn+3Ea5+Mg6Vhc-oA6o2Z-hRCPRdvf3tiw@mail.gmail.com
Traditionally, include/catalog/pg_foo.h contains extern declarations
for functions in backend/catalog/pg_foo.c, in addition to its function
as the authoritative definition of the pg_foo catalog's rowtype.
In some cases, we'd been forced to split out those extern declarations
into separate pg_foo_fn.h headers so that the catalog definitions
could be #include'd by frontend code. That problem is gone as of
commit 9c0a0de4c, so let's undo the splits to make things less
confusing.
Discussion: https://postgr.es/m/23690.1523031777@sss.pgh.pa.us
Consolidate directory and file create permissions for tools which work
with the PG data directory by adding a new module (common/file_perm.c)
that contains variables (pg_file_create_mode, pg_dir_create_mode) and
constants to initialize them (0600 for files and 0700 for directories).
Convert mkdir() calls in the backend to MakePGDirectory() if the
original call used default permissions (always the case for regular PG
directories).
Add tests to make sure permissions in PGDATA are set correctly by the
tools which modify the PG data directory.
Authors: David Steele <david@pgmasters.net>,
Adam Brightwell <adam.brightwell@crunchydata.com>
Reviewed-By: Michael Paquier, with discussion amongst many others.
Discussion: https://postgr.es/m/ad346fe6-b23e-59f1-ecb7-0e08390ad629%40pgmasters.net
Existing partition pruning is only able to work at plan time, for query
quals that appear in the parsed query. This is good but limiting, as
there can be parameters that appear later that can be usefully used to
further prune partitions.
This commit adds support for pruning subnodes of Append which cannot
possibly contain any matching tuples, during execution, by evaluating
Params to determine the minimum set of subnodes that can possibly match.
We support more than just simple Params in WHERE clauses. Support
additionally includes:
1. Parameterized Nested Loop Joins: The parameter from the outer side of the
join can be used to determine the minimum set of inner side partitions to
scan.
2. Initplans: Once an initplan has been executed we can then determine which
partitions match the value from the initplan.
Partition pruning is performed in two ways. When Params external to the plan
are found to match the partition key we attempt to prune away unneeded Append
subplans during the initialization of the executor. This allows us to bypass
the initialization of non-matching subplans meaning they won't appear in the
EXPLAIN or EXPLAIN ANALYZE output.
For parameters whose value is only known during the actual execution
then the pruning of these subplans must wait. Subplans which are
eliminated during this stage of pruning are still visible in the EXPLAIN
output. In order to determine if pruning has actually taken place, the
EXPLAIN ANALYZE must be viewed. If a certain Append subplan was never
executed due to the elimination of the partition then the execution
timing area will state "(never executed)". Whereas, if, for example in
the case of parameterized nested loops, the number of loops stated in
the EXPLAIN ANALYZE output for certain subplans may appear lower than
others due to the subplan having been scanned fewer times. This is due
to the list of matching subnodes having to be evaluated whenever a
parameter which was found to match the partition key changes.
This commit required some additional infrastructure that permits the
building of a data structure which is able to perform the translation of
the matching partition IDs, as returned by get_matching_partitions, into
the list index of a subpaths list, as exist in node types such as
Append, MergeAppend and ModifyTable. This allows us to translate a list
of clauses into a Bitmapset of all the subpath indexes which must be
included to satisfy the clause list.
Author: David Rowley, based on an earlier effort by Beena Emerson
Reviewers: Amit Langote, Robert Haas, Amul Sul, Rajkumar Raghuwanshi,
Jesper Pedersen
Discussion: https://postgr.es/m/CAOG9ApE16ac-_VVZVvv0gePSgkg_BwYEV1NBqZFqDR2bBE0X0A@mail.gmail.com
When an update moves a row between partitions (supported since
2f17844104), our normal logic for following update chains in READ
COMMITTED mode doesn't work anymore. Cross partition updates are
modeled as an delete from the old and insert into the new
partition. No ctid chain exists across partitions, and there's no
convenient space to introduce that link.
Not throwing an error in a partitioned context when one would have
been thrown without partitioning is obviously problematic. This commit
introduces infrastructure to detect when a tuple has been moved, not
just plainly deleted. That allows to throw an error when encountering
a deletion that's actually a move, while attempting to following a
ctid chain.
The row deleted as part of a cross partition update is marked by
pointing it's t_ctid to an invalid block, instead of self as a normal
update would. That was deemed to be the least invasive and most
future proof way to represent the knowledge, given how few infomask
bits are there to be recycled (there's also some locking issues with
using infomask bits).
External code following ctid chains should be updated to check for
moved tuples. The most likely consequence of not doing so is a missed
error.
Author: Amul Sul, editorialized by me
Reviewed-By: Amit Kapila, Pavan Deolasee, Andres Freund, Robert Haas
Discussion: http://postgr.es/m/CAAJ_b95PkwojoYfz0bzXU8OokcTVGzN6vYGCNVUukeUDrnF3dw@mail.gmail.com
This patch introduces INCLUDE clause to index definition. This clause
specifies a list of columns which will be included as a non-key part in
the index. The INCLUDE columns exist solely to allow more queries to
benefit from index-only scans. Also, such columns don't need to have
appropriate operator classes. Expressions are not supported as INCLUDE
columns since they cannot be used in index-only scans.
Index access methods supporting INCLUDE are indicated by amcaninclude flag
in IndexAmRoutine. For now, only B-tree indexes support INCLUDE clause.
In B-tree indexes INCLUDE columns are truncated from pivot index tuples
(tuples located in non-leaf pages and high keys). Therefore, B-tree indexes
now might have variable number of attributes. This patch also provides
generic facility to support that: pivot tuples contain number of their
attributes in t_tid.ip_posid. Free 13th bit of t_info is used for indicating
that. This facility will simplify further support of index suffix truncation.
The changes of above are backward-compatible, pg_upgrade doesn't need special
handling of B-tree indexes for that.
Bump catalog version
Author: Anastasia Lubennikova with contribition by Alexander Korotkov and me
Reviewed by: Peter Geoghegan, Tomas Vondra, Antonin Houska, Jeff Janes,
David Rowley, Alexander Korotkov
Discussion: https://www.postgresql.org/message-id/flat/56168952.4010101@postgrespro.ru
Update the built-in logical replication system to make use of the
previously added logical decoding for TRUNCATE support. Add the
required truncate callback to pgoutput and a new logical replication
protocol message.
Publications get a new attribute to determine whether to replicate
truncate actions. When updating a publication via pg_dump from an older
version, this is not set, thus preserving the previous behavior.
Author: Simon Riggs <simon@2ndquadrant.com>
Author: Marco Nenciarini <marco.nenciarini@2ndquadrant.it>
Author: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Add a new WAL record type for TRUNCATE, which is only used when
wal_level >= logical. (For physical replication, TRUNCATE is already
replicated via SMGR records.) Add new callback for logical decoding
output plugins to receive TRUNCATE actions.
Author: Simon Riggs <simon@2ndquadrant.com>
Author: Marco Nenciarini <marco.nenciarini@2ndquadrant.it>
Author: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Also enable this for postgres_fdw.
Etsuro Fujita, based on an earlier patch by Amit Langote. The larger
patch series of which this is a part has been reviewed by Amit
Langote, David Fetter, Maksim Milyutin, Álvaro Herrera, Stephen Frost,
and me. Minor documentation changes to the final version by me.
Discussion: http://postgr.es/m/29906a26-da12-8c86-4fb9-d8f88442f2b9@lab.ntt.co.jp
This patch adds new default roles named 'pg_read_server_files',
'pg_write_server_files', 'pg_execute_server_program' which
allow an administrator to GRANT to a non-superuser role the ability to
access server-side files or run programs through PostgreSQL (as the user
the database is running as). Having one of these roles allows a
non-superuser to use server-side COPY to read, write, or with a program,
and to use file_fdw (if installed by a superuser and GRANT'd USAGE on
it) to read from files or run a program.
The existing misc file functions are also changed to allow a user with
the 'pg_read_server_files' default role to read any files on the
filesystem, matching the privileges given to that role through COPY and
file_fdw from above.
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20171231191939.GR2416%40tamriel.snowman.net
The previous coding inadvertently checked the constraints for the
partitioned table rather than the target partition, which could
lead to data in a partition that fails to satisfy some constraint
on that partition. This problem seems to date back to when
table partitioning was introduced; prior to that, there was only
one target table for a COPY, so the problem didn't occur, and the
code just didn't get updated.
Etsuro Fujita, reviewed by Amit Langote and Ashutosh Bapat
Discussion: https://postgr.es/message-id/5ABA4074.1090500%40lab.ntt.co.jp
We don't actually need the insert-or-update logic, so it's clearer to
have separate functions for the inserting and updating.
Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Review comments from Andres Freund
* Consolidate code into AfterTriggerGetTransitionTable()
* Rename nodeMerge.c to execMerge.c
* Rename nodeMerge.h to execMerge.h
* Move MERGE handling in ExecInitModifyTable()
into a execMerge.c ExecInitMerge()
* Move mt_merge_subcommands flags into execMerge.h
* Rename opt_and_condition to opt_merge_when_and_condition
* Wordsmith various comments
Author: Pavan Deolasee
Reviewer: Simon Riggs
Trigger cloning to partitions was supposed to occur for user-visible
triggers only, but during development the protection that prevented it
from occurring to internal triggers was lost. Reinstate it, as well as
add a test case to ensure internal triggers (in the tested case,
triggers implementing a deferred unique constraint) are not cloned.
Without the code fix, the partitions in the test end up with different
numbers of triggers, which is clearly wrong ...
Bug in 86f575948c.
Discussion: https://postgr.es/m/20180403214903.ozfagwjcpk337uw7@alvherre.pgsql
MERGE performs actions that modify rows in the target table
using a source table or query. MERGE provides a single SQL
statement that can conditionally INSERT/UPDATE/DELETE rows
a task that would other require multiple PL statements.
e.g.
MERGE INTO target AS t
USING source AS s
ON t.tid = s.sid
WHEN MATCHED AND t.balance > s.delta THEN
UPDATE SET balance = t.balance - s.delta
WHEN MATCHED THEN
DELETE
WHEN NOT MATCHED AND s.delta > 0 THEN
INSERT VALUES (s.sid, s.delta)
WHEN NOT MATCHED THEN
DO NOTHING;
MERGE works with regular and partitioned tables, including
column and row security enforcement, as well as support for
row, statement and transition triggers.
MERGE is optimized for OLTP and is parameterizable, though
also useful for large scale ETL/ELT. MERGE is not intended
to be used in preference to existing single SQL commands
for INSERT, UPDATE or DELETE since there is some overhead.
MERGE can be used statically from PL/pgSQL.
MERGE does not yet support inheritance, write rules,
RETURNING clauses, updatable views or foreign tables.
MERGE follows SQL Standard per the most recent SQL:2016.
Includes full tests and documentation, including full
isolation tests to demonstrate the concurrent behavior.
This version written from scratch in 2017 by Simon Riggs,
using docs and tests originally written in 2009. Later work
from Pavan Deolasee has been both complex and deep, leaving
the lead author credit now in his hands.
Extensive discussion of concurrency from Peter Geoghegan,
with thanks for the time and effort contributed.
Various issues reported via sqlsmith by Andreas Seltenreich
Authors: Pavan Deolasee, Simon Riggs
Reviewer: Peter Geoghegan, Amit Langote, Tomas Vondra, Simon Riggs
Discussion:
https://postgr.es/m/CANP8+jKitBSrB7oTgT9CY2i1ObfOt36z0XMraQc+Xrz8QB0nXA@mail.gmail.comhttps://postgr.es/m/CAH2-WzkJdBuxj9PO=2QaO9-3h3xGbQPZ34kJH=HukRekwM-GZg@mail.gmail.com
LockViewRecurese() obtains view relation using heap_open() and passes
it to get_view_query() to get view info. It immediately closes the
relation then uses the returned view info by calling
LockViewRecurse_walker(). Since get_view_query() returns a pointer
within the relcache, the relcache should be kept until
LockViewRecurse_walker() returns. Otherwise the relation could point
to a garbage memory area.
Fix is moving the heap_close() call after LockViewRecurse_walker().
Problem reported by Tom Lane (buildfarm is unhappy, especially prion
since it enables -DRELCACHE_FORCE_RELEASE cpp flag), fix by me.
A followup patch will add a SKIP_LOCKED option. To avoid introducing
evermore arguments, breaking existing callers each time, introduce a
flags argument. This'll no doubt break a few external users...
Also change the MISSING_OK behaviour so a DEBUG1 debug message is
emitted when a relation is not found.
Author: Nathan Bossart
Reviewed-By: Michael Paquier and Andres Freund
Discussion: https://postgr.es/m/20180306005349.b65whmvj7z6hbe2y@alap3.anarazel.de
VACUUM updates leaf-level FSM entries immediately after cleaning the
corresponding heap blocks. fsmpage.c updates the intra-page search trees
on the leaf-level FSM pages when this happens, but it does not touch the
upper-level FSM pages, so that the released space might not actually be
findable by searchers. Previously, updating the upper-level pages happened
only at the conclusion of the VACUUM run, in a single FreeSpaceMapVacuum()
call. This is bad because the VACUUM might get canceled before ever
reaching that point, so that from the point of view of searchers no space
has been freed at all, leading to table bloat.
We can improve matters by updating the upper pages immediately after each
cycle of index-cleaning and heap-cleaning, processing just the FSM pages
corresponding to the range of heap blocks we have now fully cleaned.
This adds a small amount of extra work, since the FSM pages leading down
to each range boundary will be touched twice, but it's pretty negligible
compared to everything else going on in a large VACUUM.
If there are no indexes, VACUUM doesn't work in cycles but just cleans
each heap page on first visit. In that case we just arbitrarily update
upper FSM pages after each 8GB of heap. That maintains the goal of not
letting all this work slide until the very end, and it doesn't seem worth
expending extra complexity on a case that so seldom occurs in practice.
In either case, the FSM is fully up to date before any attempt is made
to truncate the relation, so that the most likely scenario for VACUUM
cancellation no longer results in out-of-date upper FSM pages. When
we do successfully truncate, adjusting the FSM to reflect that is now
fully handled within FreeSpaceMapTruncateRel.
Claudio Freire, reviewed by Masahiko Sawada and Jing Wang, some additional
tweaks by me
Discussion: https://postgr.es/m/CAGTBQpYR0uJCNTt3M5GOzBRHo+-GccNO1nCaQ8yEJmZKSW5q1A@mail.gmail.com
This just shows a few details about JITing, e.g. how many functions
have been JITed, and how long that took. To avoid noise in regression
tests with functions sometimes being JITed in --with-llvm builds,
disable display when COSTS OFF is specified.
Author: Andres Freund
Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de
Currently adding a column to a table with a non-NULL default results in
a rewrite of the table. For large tables this can be both expensive and
disruptive. This patch removes the need for the rewrite as long as the
default value is not volatile. The default expression is evaluated at
the time of the ALTER TABLE and the result stored in a new column
(attmissingval) in pg_attribute, and a new column (atthasmissing) is set
to true. Any existing row when fetched will be supplied with the
attmissingval. New rows will have the supplied value or the default and
so will never need the attmissingval.
Any time the table is rewritten all the atthasmissing and attmissingval
settings for the attributes are cleared, as they are no longer needed.
The most visible code change from this is in heap_attisnull, which
acquires a third TupleDesc argument, allowing it to detect a missing
value if there is one. In many cases where it is known that there will
not be any (e.g. catalog relations) NULL can be passed for this
argument.
Andrew Dunstan, heavily modified from an original patch from Serge
Rielau.
Reviewed by Tom Lane, Andres Freund, Tomas Vondra and David Rowley.
Discussion: https://postgr.es/m/31e2e921-7002-4c27-59f5-51f08404c858@2ndQuadrant.com
Originally, we treated memory context names as potentially variable in
all cases, and therefore always copied them into the context header.
Commit 9fa6f00b1 rethought this a little bit and invented a distinction
between fixed and variable names, skipping the copy step for the former.
But we can make things both simpler and more useful by instead allowing
there to be two parts to a context's identification, a fixed "name" and
an optional, variable "ident". The name supplied in the context create
call is now required to be a compile-time-constant string in all cases,
as it is never copied but just pointed to. The "ident" string, if
wanted, is supplied later. This is needed because typically we want
the ident to be stored inside the context so that it's cleaned up
automatically on context deletion; that means it has to be copied into
the context before we can set the pointer.
The cost of this approach is basically just an additional pointer field
in struct MemoryContextData, which isn't much overhead, and is bought
back entirely in the AllocSet case by not needing a headerSize field
anymore, since we no longer have to cope with variable header length.
In addition, we can simplify the internal interfaces for memory context
creation still further, saving a few cycles there. And it's no longer
true that a custom identifier disqualifies a context from participating
in aset.c's freelist scheme, so possibly there's some win on that end.
All the places that were using non-compile-time-constant context names
are adjusted to put the variable info into the "ident" instead. This
allows more effective identification of those contexts in many cases;
for example, subsidary contexts of relcache entries are now identified
by both type (e.g. "index info") and relname, where before you got only
one or the other. Contexts associated with PL function cache entries
are now identified more fully and uniformly, too.
I also arranged for plancache contexts to use the query source string
as their identifier. This is basically free for CachedPlanSources, as
they contained a copy of that string already. We pay an extra pstrdup
to do it for CachedPlans. That could perhaps be avoided, but it would
make things more fragile (since the CachedPlanSource is sometimes
destroyed first). I suspect future improvements in error reporting will
require CachedPlans to have a copy of that string anyway, so it's not
clear that it's worth moving mountains to avoid it now.
This also changes the APIs for context statistics routines so that the
context-specific routines no longer assume that output goes straight
to stderr, nor do they know all details of the output format. This
is useful immediately to reduce code duplication, and it also allows
for external code to do something with stats output that's different
from printing to stderr.
The reason for pushing this now rather than waiting for v12 is that
it rethinks some of the API changes made by commit 9fa6f00b1. Seems
better for extension authors to endure just one round of API changes
not two.
Discussion: https://postgr.es/m/CAB=Je-FdtmFZ9y9REHD7VsSrnCkiBhsA4mdsLKSPauwXtQBeNA@mail.gmail.com
Previously, FOR EACH ROW triggers were not allowed in partitioned
tables. Now we allow AFTER triggers on them, and on trigger creation we
cascade to create an identical trigger in each partition. We also clone
the triggers to each partition that is created or attached later.
This means that deferred unique keys are allowed on partitioned tables,
too.
Author: Álvaro Herrera
Reviewed-by: Peter Eisentraut, Simon Riggs, Amit Langote, Robert Haas,
Thomas Munro
Discussion: https://postgr.es/m/20171229225319.ajltgss2ojkfd3kp@alvherre.pgsql
VACUUM thought that reltuples represents the total number of tuples in
the relation, while ANALYZE counted only live tuples. This can cause
"flapping" in the value when background vacuums and analyzes happen
separately. The planner's use of reltuples essentially assumes that
it's the count of live (visible) tuples, so let's standardize on having
it mean live tuples.
Another issue is that the definition of "live tuple" isn't totally clear;
what should be done with INSERT_IN_PROGRESS or DELETE_IN_PROGRESS tuples?
ANALYZE's choices in this regard are made on the assumption that if the
originating transaction commits at all, it will happen after ANALYZE
finishes, so we should ignore the effects of the in-progress transaction
--- unless it is our own transaction, and then we should count it.
Let's propagate this definition into VACUUM, too.
Likewise propagate this definition into CREATE INDEX, and into
contrib/pgstattuple's pgstattuple_approx() function.
Tomas Vondra, reviewed by Haribabu Kommi, some corrections by me
Discussion: https://postgr.es/m/16db4468-edfa-830a-f921-39a50498e77e@2ndquadrant.com
Previously, a value was included in the MCV list if its frequency was
25% larger than the estimated average frequency of all nonnull values
in the table. For uniform distributions, that can lead to values
being included in the MCV list and significantly overestimated on the
basis of relatively few (sometimes just 2) instances being seen in the
sample. For non-uniform distributions, it can lead to too few values
being included in the MCV list, since the overall average frequency
may be dominated by a small number of very common values, while the
remaining values may still have a large spread of frequencies, causing
both substantial overestimation and underestimation of the remaining
values. Furthermore, increasing the statistics target may have little
effect because the overall average frequency will remain relatively
unchanged.
Instead, populate the MCV list with the largest set of common values
that are statistically significantly more common than the average
frequency of the remaining values. This takes into account the
variance of the sample counts, which depends on the counts themselves
and on the proportion of the table that was sampled. As a result, it
constrains the relative standard error of estimates based on the
frequencies of values in the list, reducing the chances of too many
values being included. At the same time, it allows more values to be
included, since the MCVs need only be more common than the remaining
non-MCVs, rather than the overall average. Thus it tends to produce
fewer MCVs than the previous code for uniform distributions, and more
for non-uniform distributions, reducing estimation errors in both
cases. In addition, the algorithm responds better to increasing the
statistics target, allowing more values to be included in the MCV list
when more of the table is sampled.
Jeff Janes, substantially modified by me. Reviewed by John Naylor and
Tomas Vondra.
Discussion: https://postgr.es/m/CAMkU=1yvdGvW9TmiLAhz2erFnvnPFYHbOZuO+a=4DVkzpuQ2tw@mail.gmail.com
My commit 4dba331cb3 that moved around CommandCounterIncrement calls
in partitioning DDL code unearthed a problem with the relcache handling
for the 'default' partition: the construction of a correct relcache
entry for the partitioned table was at the mercy of lack of CCI calls in
non-trivial amounts of code. This was prone to creating problems later
on, as the code develops. This was visible as a test failure in a
compile with RELCACHE_FORCE_RELASE (buildfarm member prion).
The problem is that after the mentioned commit it was possible to create
a relcache entry that had incomplete information regarding the default
partition because I introduced a CCI between adding the catalog entries
for the default partition (StorePartitionBound) and the update of
pg_partitioned_table entry for its parent partitioned table
(update_default_partition_oid). It seems the best fix is to move the
latter so that it occurs inside the former; the purposeful lack of
intervening CCI should be more obvious, and harder to break.
I also remove a check in RelationBuildPartitionDesc that returns NULL if
the key is not set. I couldn't find any place that needs this hack
anymore; probably it was required because of bugs that have since been
fixed.
Fix a few typos I noticed while reviewing the code involved.
Discussion: https://postgr.es/m/20180320182659.nyzn3vqtjbbtfgwq@alvherre.pgsql
Logical decoding should not publish anything about tables created as
part of a heap rewrite during DDL. Those tables don't exist externally,
so consumers of logical decoding cannot do anything sensible with that
information. In ab28feae2b, we worked
around this for built-in logical replication, but that was hack.
This is a more proper fix: We mark such transient heaps using the new
field pg_class.relwrite, linking to the original relation OID. By
default, we ignore them in logical decoding before they get to the
output plugin. Optionally, a plugin can register their interest in
getting such changes, if they handle DDL specially, in which case the
new field will help them get information about the actual table.
Reviewed-by: Craig Ringer <craig@2ndquadrant.com>
It makes sense to do the CCIs in the places that do catalog updates,
rather than before the places that error out because the former ones
fail to do it. In particular, it looks like StorePartitionBound() and
IndexSetParentIndex() ought to make their own CCIs.
Per review comments from Peter Eisentraut for row-level triggers on
partitioned tables.
Discussion: https://postgr.es/m/20171229225319.ajltgss2ojkfd3kp@alvherre.pgsql
refresh_by_match_merge() has some issues in the way it builds a SQL
query to construct the "diff" table:
1. It doesn't require the selected unique index(es) to be indimmediate.
2. It doesn't pay attention to the particular equality semantics enforced
by a given index, but just assumes that they must be those of the column
datatype's default btree opclass.
3. It doesn't check that the indexes are btrees.
4. It's insufficiently careful to ensure that the parser will pick the
intended operator when parsing the query. (This would have been a
security bug before CVE-2018-1058.)
5. It's not careful about indexes on system columns.
The way to fix#4 is to make use of the existing code in ri_triggers.c
for generating an arbitrary binary operator clause. I chose to move
that to ruleutils.c, since that seems a more reasonable place to be
exporting such functionality from than ri_triggers.c.
While #1, #3, and #5 are just latent given existing feature restrictions,
and #2 doesn't arise in the core system for lack of alternate opclasses
with different equality behaviors, #4 seems like an issue worth
back-patching. That's the bulk of the change anyway, so just back-patch
the whole thing to 9.4 where this code was introduced.
Discussion: https://postgr.es/m/13836.1521413227@sss.pgh.pa.us
Jeff Janes discovered that commit 7ca25b7de made one of the queries run by
REFRESH MATERIALIZED VIEW CONCURRENTLY perform badly. The root cause is
bad cardinality estimation for correlated quals, but a principled solution
to that problem is some way off, especially since the planner lacks any
statistics about whole-row variables. Moreover, in non-error cases this
query produces no rows, meaning it must be run to completion; but use of
LIMIT 1 encourages the planner to pick a fast-start, slow-completion plan,
exactly not what we want. Remove the LIMIT clause, and instead rely on
the count parameter we pass to SPI_execute() to prevent excess work if the
query does return some rows.
While we've heard no field reports of planner misbehavior with this query,
it could be that people are having performance issues that haven't reached
the level of pain needed to cause a bug report. In any case, that LIMIT
clause can't possibly do anything helpful with any existing version of the
planner, and it demonstrably can cause bad choices in some cases, so
back-patch to 9.4 where the code was introduced.
Thomas Munro
Discussion: https://postgr.es/m/CAMkU=1z-JoGymHneGHar1cru4F1XDfHqJDzxP_CtK5cL3DOfmg@mail.gmail.com
We make some changes to ModifyTableState and the EState it uses whenever
we route tuples to partitions; but we weren't restoring properly in all
cases, possibly causing crashes when partitions with different tuple
descriptors are targeted by tuples inserted in the same command.
Refactor some code, creating ExecPrepareTupleRouting, to encapsulate the
needed state changing logic, and have it invoked one level above its
current place (ie. put it in ExecModifyTable instead of ExecInsert);
this makes it all more readable.
Add a test case to exercise this.
We don't support having views as partitions; and since only views can
have INSTEAD OF triggers, there is no point in testing for INSTEAD OF
when processing insertions into a partitioned table. Remove code that
appears to support this (but which is actually never relevant.)
In passing, fix location of some very confusing comments in
ModifyTableState.
Reported-by: Amit Langote
Author: Etsuro Fujita, Amit Langote
Discussion: https://postgr/es/m/0473bf5c-57b1-f1f7-3d58-455c2230bc5f@lab.ntt.co.jp
This allows to deduplicate some existing code, but mainly avoids some
duplication in upcoming commits.
In passing, fix variable names indicating wrong unit (seconds instead
of ms).
Author: Andres Freund
Discussion: https://postgr.es/m/20180314002740.cah3mdsonz5mxney@alap3.anarazel.de
'long' is not useful type across platforms, as it's 32bit on 32 bit
platforms, and even on some 64bit platforms (e.g. windows) it's still
only 32bits wide.
As ExplainPropertyInteger should never be performance critical, change
it to accept a 64bit argument and remove ExplainPropertyLong.
Author: Andres Freund
Discussion: https://postgr.es/m/20180314164832.n56wt7zcbpzi6zxe@alap3.anarazel.de
We call this thing a "transaction block" everywhere except in a few
functions, where it is mysteriously called a "transaction chain". In
the SQL standard, a transaction chain is something different. So rename
these functions to match the common terminology.
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Fix the warnings created by the compiler warning options
-Wformat-overflow=2 -Wformat-truncation=2, supported since GCC 7. This
is a more aggressive variant of the fixes in
6275f5d28a, which GCC 7 warned about by
default.
The issues are all harmless, but some dubious coding patterns are
cleaned up.
One issue that is of external interest is that BGW_MAXLEN is increased
from 64 to 96. Apparently, the old value would cause the bgw_name of
logical replication workers to be truncated in some circumstances.
But this doesn't actually add those warning options. It appears that
the warnings depend a bit on compilation and optimization options, so it
would be annoying to have to keep up with that. This is more of a
once-in-a-while cleanup.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
In a top-level CALL, the values of INOUT arguments will be returned as a
result row. In PL/pgSQL, the values are assigned back to the input
arguments. In other languages, the same convention as for return a
record from a function is used. That does not require any code changes
in the PL implementations.
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
The existing logic for updating pg_class.reltuples trusted the sampling
results only for the pages ANALYZE actually visited, preferring to
believe the previous tuple density estimate for all the unvisited pages.
While there's some rationale for doing that for VACUUM (first that
VACUUM is likely to visit a very nonrandom subset of pages, and second
that we know for sure that the unvisited pages did not change), there's
no such rationale for ANALYZE: by assumption, it's looked at an unbiased
random sample of the table's pages. Furthermore, in a very large table
ANALYZE will have examined only a tiny fraction of the table's pages,
meaning it cannot slew the overall density estimate very far at all.
In a table that is physically growing, this causes reltuples to increase
nearly proportionally to the change in relpages, regardless of what is
actually happening in the table. This has been observed to cause reltuples
to become so much larger than reality that it effectively shuts off
autovacuum, whose threshold for doing anything is a fraction of reltuples.
(Getting to the point where that would happen seems to require some
additional, not well understood, conditions. But it's undeniable that if
reltuples is seriously off in a large table, ANALYZE alone will not fix it
in any reasonable number of iterations, especially not if the table is
continuing to grow.)
Hence, restrict the use of vac_estimate_reltuples() to VACUUM alone,
and in ANALYZE, just extrapolate from the sample pages on the assumption
that they provide an accurate model of the whole table. If, by very bad
luck, they don't, at least another ANALYZE will fix it; in the old logic
a single bad estimate could cause problems indefinitely.
In HEAD, let's remove vac_estimate_reltuples' is_analyze argument
altogether; it was never used for anything and now it's totally pointless.
But keep it in the back branches, in case any third-party code is calling
this function.
Per bug #15005. Back-patch to all supported branches.
David Gould, reviewed by Alexander Kuzmenkov, cosmetic changes by me
Discussion: https://postgr.es/m/20180117164916.3fdcf2e9@engels
CREATE TABLE / LIKE with a bigint identity column would fail on
platforms where long is 32 bits. Copying the sequence values used
makeInteger(), which would truncate the 64-bit sequence data to 32 bits.
To fix, use makeFloat() instead, like the parser. (This does not
actually make use of floats, but stores the values as strings.)
Bug: #15096
Reviewed-by: Michael Paquier <michael@paquier.xyz>
If a table containing a primary key is attach as partition to a
partitioned table which has a primary key with a different definition,
we would happily create a second one in the new partition. Oops. It
turns out that this is because an error check in DefineIndex is executed
only if you tell it that it's being run by ALTER TABLE, and the original
code here wasn't. Change it so that it does.
Added a couple of test cases for this, also. A previously working test
started to fail in a different way than before patch because the new
check is called earlier; change the PK to plain UNIQUE so that the new
behavior isn't invoked, so that the test continues to verify what we
want it to verify.
Reported by: Noriyoshi Shinoda
Discussion: https://postgr.es/m/DF4PR8401MB102060EC2615EC9227CC73F7EEDF0@DF4PR8401MB1020.NAMPRD84.PROD.OUTLOOK.COM
One of the things canonicalize_qual() does is to remove constant-NULL
subexpressions of top-level AND/OR clauses. It does that on the assumption
that what it's given is a top-level WHERE clause, so that NULL can be
treated like FALSE. Although this is documented down inside a subroutine
of canonicalize_qual(), it wasn't mentioned in the documentation of that
function itself, and some callers hadn't gotten that memo.
Notably, commit d007a9505 caused get_relation_constraints() to apply
canonicalize_qual() to CHECK constraints. That allowed constraint
exclusion to misoptimize situations in which a CHECK constraint had a
provably-NULL subclause, as seen in the regression test case added here,
in which a child table that should be scanned is not. (Although this
thinko is ancient, the test case doesn't fail before 9.2, for reasons
I've not bothered to track down in detail. There may be related cases
that do fail before that.)
More recently, commit f0e44751d added an independent bug by applying
canonicalize_qual() to index expressions, which is even sillier since
those might not even be boolean. If they are, though, I think this
could lead to making incorrect index entries for affected index
expressions in v10. I haven't attempted to prove that though.
To fix, add an "is_check" parameter to canonicalize_qual() to specify
whether it should assume WHERE or CHECK semantics, and make it perform
NULL-elimination accordingly. Adjust the callers to apply the right
semantics, or remove the call entirely in cases where it's not known
that the expression has one or the other semantics. I also removed
the call in some cases involving partition expressions, where it should
be a no-op because such expressions should be canonical already ...
and was a no-op, independently of whether it could in principle have
done something, because it was being handed the qual in implicit-AND
format which isn't what it expects. In HEAD, add an Assert to catch
that type of mistake in future.
This represents an API break for external callers of canonicalize_qual().
While that's intentional in HEAD to make such callers think about which
case applies to them, it seems like something we probably wouldn't be
thanked for in released branches. Hence, in released branches, the
extra parameter is added to a new function canonicalize_qual_ext(),
and canonicalize_qual() is a wrapper that retains its old behavior.
Patch by me with suggestions from Dean Rasheed. Back-patch to all
supported branches.
Discussion: https://postgr.es/m/24475.1520635069@sss.pgh.pa.us
Commit b08df9cab left things rather poorly documented as far as the
exact semantics of "clause_is_check" mode went. Also, that mode did
not really work correctly for predicate_refuted_by; although given the
lack of specification as to what it should do, as well as the lack
of any actual use-case, that's perhaps not surprising.
Rename "clause_is_check" to "weak" proof mode, and provide specifications
for what it should do. I defined weak refutation as meaning "truth of A
implies non-truth of B", which makes it possible to use the mode in the
part of relation_excluded_by_constraints that checks for mutually
contradictory WHERE clauses. Fix up several places that did things wrong
for that definition. (As far as I can see, these errors would only lead
to failure-to-prove, not incorrect claims of proof, making them not
serious bugs even aside from the fact that v10 contains no use of this
mode. So there seems no need for back-patching.)
In addition, teach predicate_refuted_by_recurse that it can use
predicate_implied_by_recurse after all when processing a strong NOT-clause,
so long as it asks for the correct proof strength. This is an optimization
that could have been included in commit b08df9cab, but wasn't.
Also, simplify and generalize the logic that checks for whether nullness of
the argument of IS [NOT] NULL would force overall nullness of the predicate
or clause. (This results in a change in the partition_prune test's output,
as it is now able to prune an all-nulls partition that it did not recognize
before.)
In passing, in PartConstraintImpliedByRelConstraint, remove bogus
conversion of the constraint list to explicit-AND form and then right back
again; that accomplished nothing except forcing a useless extra level of
recursion inside predicate_implied_by.
Discussion: https://postgr.es/m/5983.1520487191@sss.pgh.pa.us
Apparently, it doesn't work to use a plain cstring as a Name datum: you
may end up having random bytes because of failing to zero the bytes
after the terminating \0, as indicated by valgrind. I introduced this
bug in 5564c11815, so backpatch this fix to REL_10_STABLE, like that
commit.
While at it, fix a slightly misleading comment, pointed out by David
Rowley.
The LIKE INCLUDING ALL clause to CREATE TABLE intuitively indicates
cloning of extended statistics on the source table, but it failed to do
so. Patch it up so that it does. Also include an INCLUDING STATISTICS
option to the LIKE clause, so that the behavior can be requested
individually, or excluded individually.
While at it, reorder the INCLUDING options, both in code and in docs, in
alphabetical order which makes more sense than feature-implementation
order that was previously used.
Backpatch this to Postgres 10, where extended statistics were
introduced, because this is seen as an oversight in a fresh feature
which is better to get consistent from the get-go instead of changing
only in pg11.
In pg11, comments on statistics objects are cloned too. In pg10 they
are not, because I (Álvaro) was too coward to change the parse node as
required to support it. Also, in pg10 I chose not to renumber the
parser symbols for the various INCLUDING options in LIKE, for the same
reason. Any corresponding user-visible changes (docs) are backpatched,
though.
Reported-by: Stephen Froehlich
Author: David Rowley
Reviewed-by: Álvaro Herrera, Tomas Vondra
Discussion: https://postgr.es/m/CY1PR0601MB1927315B45667A1B679D0FD5E5EF0@CY1PR0601MB1927.namprd06.prod.outlook.com
The new column distinguishes normal functions, procedures, aggregates,
and window functions. This replaces the existing columns proisagg and
proiswindow, and replaces the convention that procedures are indicated
by prorettype == 0. Also change prorettype to be VOIDOID for procedures.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
A before-update row trigger may choose to return the "new" or "old" tuple
unmodified. ExecBRUpdateTriggers failed to consider the second
possibility, and would proceed to free the "old" tuple even if it was the
one returned, leading to subsequent access to already-deallocated memory.
In debug builds this reliably leads to an "invalid memory alloc request
size" failure; in production builds it might accidentally work, but data
corruption is also possible.
This is a very old bug. There are probably a couple of reasons it hasn't
been noticed up to now. It would be more usual to return NULL if one
wanted to suppress the update action; returning "old" is significantly less
efficient since the update will occur anyway. Also, none of the standard
PLs would ever cause this because they all returned freshly-manufactured
tuples even if they were just copying "old". But commit 4b93f5799 changed
that for plpgsql, making it possible to see the bug with a plpgsql trigger.
Still, this is certainly legal behavior for a trigger function, so it's
ExecBRUpdateTriggers's fault not plpgsql's.
It seems worth creating a test case that exercises returning "old" directly
with a C-language trigger; testing this through plpgsql seems unreliable
because its behavior might change again.
Report and fix by Rushabh Lathia; regression test case by me.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAGPqQf1P4pjiNPrMof=P_16E-DFjt457j+nH2ex3=nBTew7tXw@mail.gmail.com
To support parameters in CALL, move the parse analysis of the procedure
and arguments into the global transformation phase, so that the parser
hooks can be applied. And then at execution time pass the parameters
from ProcessUtility on to ExecuteCallStmt.
It's not necessary to fully initialize the executor data structures
for partitions to which no tuples are ever routed. Consider, for
example, an INSERT statement that inserts only one row: it only cares
about the partition to which that one row is routed. The new function
ExecInitPartitionInfo performs the initialization in question only
when a particular partition is about to receive a tuple. This includes
creating, validating, and saving a pointer to the ResultRelInfo,
setting up for speculative insertions, translating WCOs and
initializing the resulting expressions, translating returning lists
and building the appropriate projection information, and setting up a
tuple conversion map.
One thing that's not deferred is locking the child partitions; that
seems desirable but would need more thought. Still, testing shows
that this makes single-row inserts significantly faster on a table
with many partitions without harming the bulk-insert case.
Amit Langote, reviewed by Etsuro Fujita, with a few changes by me
Discussion: http://postgr.es/m/8975331d-d961-cbdd-f862-fdd3d97dc2d0@lab.ntt.co.jp
If we restrict unique constraints on partitioned tables so that they
must always include the partition key, then our standard approach to
unique indexes already works --- each unique key is forced to exist
within a single partition, so enforcing the unique restriction in each
index individually is enough to have it enforced globally. Therefore we
can implement unique indexes on partitions by simply removing a few
restrictions (and adding others.)
Discussion: https://postgr.es/m/20171222212921.hi6hg6pem2w2t36z@alvherre.pgsql
Discussion: https://postgr.es/m/20171229230607.3iib6b62fn3uaf47@alvherre.pgsql
Reviewed-by: Simon Riggs, Jesper Pedersen, Peter Eisentraut, Jaime
Casanova, Amit Langote
The reason for doing so is that it will allow expression evaluation to
optimize based on the underlying tupledesc. In particular it will
allow to JIT tuple deforming together with the expression itself.
For that expression initialization needs to be moved after the
relevant slots are initialized - mostly unproblematic, except in the
case of nodeWorktablescan.c.
After doing so there's no need for ExecAssignResultType() and
ExecAssignResultTypeFromTL() anymore, as all former callers have been
converted to create a slot with a fixed descriptor.
When creating a slot with a fixed descriptor, tts_values/isnull can be
allocated together with the main slot, reducing allocation overhead
and increasing cache density a bit.
Author: Andres Freund
Discussion: https://postgr.es/m/20171206093717.vqdxe5icqttpxs3p@alap3.anarazel.de
Prematurely freeing the EState used to evaluate CALL arguments led, in some
cases, to passing dangling pointers to the procedure. This was masked in
trivial cases because the argument pointers would point to Const nodes in
the original expression tree, and in some other cases because the result
value would end up in the standalone ExprContext rather than in memory
belonging to the EState --- but that wasn't exactly high quality
programming either, because the standalone ExprContext was never
explicitly freed, breaking assorted API contracts.
In addition, using a separate EState for each argument was just silly.
So let's use just one EState, and one ExprContext, and make the latter
belong to the former rather than be standalone, and clean up the EState
(and hence the ExprContext) post-call.
While at it, improve the function's commentary a bit.
Discussion: https://postgr.es/m/29173.1518282748@sss.pgh.pa.us
CALL statements cannot support sub-SELECTs in the arguments of the called
procedure, since they just use ExecEvalExpr to evaluate such arguments.
Teach transformSubLink() to reject the case, as it already does for other
contexts in which subqueries are not supported.
In passing, s/EXPR_KIND_CALL/EXPR_KIND_CALL_ARGUMENT/ to make that enum
symbol line up more closely with the phrasing of the error messages it is
associated with. And fix someone's weak grasp of English grammar in the
preceding EXPR_KIND_PARTITION_EXPRESSION addition. Also update an
incorrect comment in resolve_unique_index_expr (possibly it was correct
when written, but nowadays transformExpr definitely does reject SRFs here).
Per report from Pavel Stehule --- but this resolves only one of the bugs
he mentions.
Discussion: https://postgr.es/m/CAFj8pRDxOwPPzpA8i+AQeDQFj7bhVw-dR2==rfWZ3zMGkm568Q@mail.gmail.com
Doing so causes EXPLAIN ANALYZE to show trigger statistics multiple
times. Commit 2f17844104 seems to
be to blame for this.
Amit Langote, revieed by Amit Khandekar, Etsuro Fujita, and me.
This patch adds the ability to use "RANGE offset PRECEDING/FOLLOWING"
frame boundaries in window functions. We'd punted on that back in the
original patch to add window functions, because it was not clear how to
do it in a reasonably data-type-extensible fashion. That problem is
resolved here by adding the ability for btree operator classes to provide
an "in_range" support function that defines how to add or subtract the
RANGE offset value. Factoring it this way also allows the operator class
to avoid overflow problems near the ends of the datatype's range, if it
wishes to expend effort on that. (In the committed patch, the integer
opclasses handle that issue, but it did not seem worth the trouble to
avoid overflow failures for datetime types.)
The patch includes in_range support for the integer_ops opfamily
(int2/int4/int8) as well as the standard datetime types. Support for
other numeric types has been requested, but that seems like suitable
material for a follow-on patch.
In addition, the patch adds GROUPS mode which counts the offset in
ORDER-BY peer groups rather than rows, and it adds the frame_exclusion
options specified by SQL:2011. As far as I can see, we are now fully
up to spec on window framing options.
Existing behaviors remain unchanged, except that I changed the errcode
for a couple of existing error reports to meet the SQL spec's expectation
that negative "offset" values should be reported as SQLSTATE 22013.
Internally and in relevant parts of the documentation, we now consistently
use the terminology "offset PRECEDING/FOLLOWING" rather than "value
PRECEDING/FOLLOWING", since the term "value" is confusingly vague.
Oliver Ford, reviewed and whacked around some by me
Discussion: https://postgr.es/m/CAGMVOdu9sivPAxbNN0X+q19Sfv9edEPv=HibOJhB14TJv_RCQg@mail.gmail.com
Investigation of 2d2d06b7e2 revealed that
identity values were not applied in some further cases, including
logical replication subscribers, VALUES RTEs, and ALTER TABLE ... ADD
COLUMN. To fix all that, apply the identity column expression in
build_column_default() instead of repeating the same logic at each call
site.
For ALTER TABLE ... ADD COLUMN ... IDENTITY, the previous coding
completely ignored that existing rows for the new column should have
values filled in from the identity sequence. The coding using
build_column_default() fails for this because the sequence ownership
isn't registered until after ALTER TABLE, and we can't do it before
because we don't have the column in the catalog yet. So we specially
remember in ColumnDef the sequence name that we decided on and build a
custom NextValueExpr using that.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
To make this work, tuplesort.c and logtape.c must also support
parallelism, so this patch adds that infrastructure and then applies
it to the particular case of parallel btree index builds. Testing
to date shows that this can often be 2-3x faster than a serial
index build.
The model for deciding how many workers to use is fairly primitive
at present, but it's better than not having the feature. We can
refine it as we get more experience.
Peter Geoghegan with some help from Rushabh Lathia. While Heikki
Linnakangas is not an author of this patch, he wrote other patches
without which this feature would not have been possible, and
therefore the release notes should possibly credit him as an author
of this feature. Reviewed by Claudio Freire, Heikki Linnakangas,
Thomas Munro, Tels, Amit Kapila, me.
Discussion: http://postgr.es/m/CAM3SWZQKM=Pzc=CAHzRixKjp2eO5Q0Jg1SoFQqeXFQ647JiwqQ@mail.gmail.com
Discussion: http://postgr.es/m/CAH2-Wz=AxWqDoVvGU7dq856S4r6sJAj6DBn7VMtigkB33N5eyg@mail.gmail.com
We have a lot of code in which option names, which from the user's
viewpoint are logically keywords, are passed through the grammar as plain
identifiers, and then matched to string literals during command execution.
This approach avoids making words into lexer keywords unnecessarily. Some
places matched these strings using plain strcmp, some using pg_strcasecmp.
But the latter should be unnecessary since identifiers would have been
downcased on their way through the parser. Aside from any efficiency
concerns (probably not a big factor), the lack of consistency in this area
creates a hazard of subtle bugs due to different places coming to different
conclusions about whether two option names are the same or different.
Hence, standardize on using strcmp() to match any option names that are
expected to have been fed through the parser.
This does create a user-visible behavioral change, which is that while
formerly all of these would work:
alter table foo set (fillfactor = 50);
alter table foo set (FillFactor = 50);
alter table foo set ("fillfactor" = 50);
alter table foo set ("FillFactor" = 50);
now the last case will fail because that double-quoted identifier is
different from the others. However, none of our documentation says that
you can use a quoted identifier in such contexts at all, and we should
discourage doing so since it would break if we ever decide to parse such
constructs as true lexer keywords rather than poor man's substitutes.
So this shouldn't create a significant compatibility issue for users.
Daniel Gustafsson, reviewed by Michael Paquier, small changes by me
Discussion: https://postgr.es/m/29405B24-564E-476B-98C0-677A29805B84@yesql.se
This clause was superseded by SQL-standard syntax back in 7.3.
We've kept it around for backwards-compatibility purposes ever since;
but 15 years seems like long enough for that, especially seeing that
there are undocumented weirdnesses in how it interacts with the
SQL-standard syntax for specifying the same options.
Michael Paquier, per an observation by Daniel Gustafsson;
some small cosmetic adjustments to nearby code by me.
Discussion: https://postgr.es/m/20180115022748.GB1724@paquier.xyz
get_relation_info() was too optimistic about opening indexes in
partitioned tables, which would raise errors when any queries were
planned on such tables. Fix by ignoring any indexes of the partitioned
kind.
CLUSTER (and ALTER TABLE CLUSTER ON) had a similar problem. Fix by
disallowing these commands in partitioned tables.
Fallout from 8b08f7d482.
In each of the supplied procedural languages (PL/pgSQL, PL/Perl,
PL/Python, PL/Tcl), add language-specific commit and rollback
functions/commands to control transactions in procedures in that
language. Add similar underlying functions to SPI. Some additional
cleanup so that transaction commit or abort doesn't blow away data
structures still used by the procedure call. Add execution context
tracking to CALL and DO statements so that transaction control commands
can only be issued in top-level procedure and block calls, not function
calls or other procedure or block calls.
- SPI
Add a new function SPI_connect_ext() that is like SPI_connect() but
allows passing option flags. The only option flag right now is
SPI_OPT_NONATOMIC. A nonatomic SPI connection can execute transaction
control commands, otherwise it's not allowed. This is meant to be
passed down from CALL and DO statements which themselves know in which
context they are called. A nonatomic SPI connection uses different
memory management. A normal SPI connection allocates its memory in
TopTransactionContext. For nonatomic connections we use PortalContext
instead. As the comment in SPI_connect_ext() (previously SPI_connect())
indicates, one could potentially use PortalContext in all cases, but it
seems safest to leave the existing uses alone, because this stuff is
complicated enough already.
SPI also gets new functions SPI_start_transaction(), SPI_commit(), and
SPI_rollback(), which can be used by PLs to implement their transaction
control logic.
- portalmem.c
Some adjustments were made in the code that cleans up portals at
transaction abort. The portal code could already handle a command
*committing* a transaction and continuing (e.g., VACUUM), but it was not
quite prepared for a command *aborting* a transaction and continuing.
In AtAbort_Portals(), remove the code that marks an active portal as
failed. As the comment there already predicted, this doesn't work if
the running command wants to keep running after transaction abort. And
it's actually not necessary, because pquery.c is careful to run all
portal code in a PG_TRY block and explicitly runs MarkPortalFailed() if
there is an exception. So the code in AtAbort_Portals() is never used
anyway.
In AtAbort_Portals() and AtCleanup_Portals(), we need to be careful not
to clean up active portals too much. This mirrors similar code in
PreCommit_Portals().
- PL/Perl
Gets new functions spi_commit() and spi_rollback()
- PL/pgSQL
Gets new commands COMMIT and ROLLBACK.
Update the PL/SQL porting example in the documentation to reflect that
transactions are now possible in procedures.
- PL/Python
Gets new functions plpy.commit and plpy.rollback.
- PL/Tcl
Gets new commands commit and rollback.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
When an UPDATE causes a row to no longer match the partition
constraint, try to move it to a different partition where it does
match the partition constraint. In essence, the UPDATE is split into
a DELETE from the old partition and an INSERT into the new one. This
can lead to surprising behavior in concurrency scenarios because
EvalPlanQual rechecks won't work as they normally did; the known
problems are documented. (There is a pending patch to improve the
situation further, but it needs more review.)
Amit Khandekar, reviewed and tested by Amit Langote, David Rowley,
Rajkumar Raghuwanshi, Dilip Kumar, Amul Sul, Thomas Munro, Álvaro
Herrera, Amit Kapila, and me. A few final revisions by me.
Discussion: http://postgr.es/m/CAJ3gD9do9o2ccQ7j7+tSgiE1REY65XRiMb=yJO3u3QhyP8EEPQ@mail.gmail.com
AclObjectKind was basically just another enumeration for object types,
and we already have a preferred one for that. It's only used in
aclcheck_error. By using ObjectType instead, we can also give some more
precise error messages, for example "index" instead of "relation".
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
There used to be a lot of different *Type and *Kind symbol groups to
address objects within different commands, most of which have been
replaced by ObjectType, starting with
b256f24264. But this conversion was never
done for the ACL commands until now.
This change ends up being just a plain replacement of the types and
symbols, without any code restructuring needed, except deleting some now
redundant code.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Stephen Frost <sfrost@snowman.net>
When CREATE INDEX is run on a partitioned table, create catalog entries
for an index on the partitioned table (which is just a placeholder since
the table proper has no data of its own), and recurse to create actual
indexes on the existing partitions; create them in future partitions
also.
As a convenience gadget, if the new index definition matches some
existing index in partitions, these are picked up and used instead of
creating new ones. Whichever way these indexes come about, they become
attached to the index on the parent table and are dropped alongside it,
and cannot be dropped on isolation unless they are detached first.
To support pg_dump'ing these indexes, add commands
CREATE INDEX ON ONLY <table>
(which creates the index on the parent partitioned table, without
recursing) and
ALTER INDEX ATTACH PARTITION
(which is used after the indexes have been created individually on each
partition, to attach them to the parent index). These reconstruct prior
database state exactly.
Reviewed-by: (in alphabetical order) Peter Eisentraut, Robert Haas, Amit
Langote, Jesper Pedersen, Simon Riggs, David Rowley
Discussion: https://postgr.es/m/20171113170646.gzweigyrgg6pwsg4@alvherre.pgsql
For no apparent reason, this function was using a 16bit-wide inhseqno
value, rather than the correct 32 bit width which is what is stored in
the pg_inherits catalog. This becomes evident if you try to create a
table with more than 65535 parents, because this error appears:
ERROR: duplicate key value violates unique constraint «pg_inherits_relid_seqno_index»
DETAIL: Key (inhrelid, inhseqno)=(329371, 0) already exists.
Needless to say, having so many parents is an uncommon situations, which
explains why this error has never been reported despite being having
been introduced with the Postgres95 1.01 sources in commit d31084e9d111:
https://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/commands/creatinh.c;hb=d31084e9d111#l349
Backpatch all the way back.
David Rowley noticed this while reviewing a patch of mine.
Discussion: https://postgr.es/m/CAKJS1f8Dn7swSEhOWwzZzssW7747YB=2Hi+T7uGud40dur69-g@mail.gmail.com
This should have been done in commit 18ce3a4ab, which added that parameter
to ExplainOneQuery, but it was overlooked. This makes it impossible for
a user of the hook to pass the queryEnv down to ExplainOnePlan.
It's too late to change this API in v10, I suppose, but fortunately
passing NULL to ExplainOnePlan will work in nearly all interesting
cases in v10. That might not be true forever, so we'd better fix it.
Tatsuro Yamada, reviewed by Thomas Munro
Discussion: https://postgr.es/m/890e8dd9-c1c7-a422-6892-874f5eaee048@lab.ntt.co.jp
After having gotten rid of PortalGetHeapMemory(), there seems little
reason to keep one Portal access macro around that offers no actual
abstraction and isn't consistently used anyway.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Rename PortalMemory to TopPortalContext, to avoid confusion with
PortalContext and align naming with similar top-level memory contexts.
Rename PortalData's "heap" field to portalContext. The "heap" naming
seems quite antiquated and confusing. Also get rid of the
PortalGetHeapMemory() macro and access the field directly, which we do
for other portal fields, so this abstraction doesn't buy anything.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
At present, we always raise an ERROR if the partition constraint
is violated, but a pending patch for UPDATE tuple routing will
consider instead moving the tuple to the correct partition.
Refactor to make that simpler.
Amit Khandekar, reviewed by Amit Langote, David Rowley, and me.
Discussion: http://postgr.es/m/CAJ3gD9cue54GbEzfV-61nyGpijvjZgCcghvLsB0_nL8Nm8HzCA@mail.gmail.com
Generalize is_partition_attr to has_partition_attrs and make it
accessible from outside tablecmds.c. Change map_partition_varattnos
to clarify that it can be used for mapping between any two relations
in a partitioning hierarchy, not just parent -> child.
Amit Khandekar, reviewed by Amit Langote, David Rowley, and me.
Some comment changes by me.
Discussion: http://postgr.es/m/CAJ3gD9fWfxgKC+PfJZF3hkgAcNOy-LpfPxVYitDEXKHjeieWQQ@mail.gmail.com
Instead of having ExecSetupPartitionTupleRouting return multiple out
parameters, have it return a pointer to a structure containing all of
those different things. Also, provide and use a cleanup function,
ExecCleanupTupleRouting, instead of cleaning up all of the resources
allocated by ExecSetupPartitionTupleRouting individually.
Amit Khandekar, reviewed by Amit Langote, David Rowley, and me
Discussion: http://postgr.es/m/CAJ3gD9fWfxgKC+PfJZF3hkgAcNOy-LpfPxVYitDEXKHjeieWQQ@mail.gmail.com
Multiple sessions doing CREATE INDEX CONCURRENTLY simultaneously are
supposed to be able to work in parallel, as evidenced by fixes in commit
c3d09b3bd2 specifically to support this case. In reality, one of the
sessions would be aborted by a misterious "deadlock detected" error.
Jeff Janes diagnosed that this is because of leftover snapshots used for
system catalog scans -- this was broken by 8aa3e47510 keeping track of
(registering) the catalog snapshot. To fix the deadlocks, it's enough
to de-register that snapshot prior to waiting.
Backpatch to 9.4, which introduced MVCC catalog scans.
Include an isolationtester spec that 8 out of 10 times reproduces the
deadlock with the unpatched code for me (Álvaro).
Author: Jeff Janes
Diagnosed-by: Jeff Janes
Reported-by: Jeremy Finzel
Discussion: https://postgr.es/m/CAMa1XUhHjCv8Qkx0WOr1Mpm_R4qxN26EibwCrj0Oor2YBUFUTg%40mail.gmail.com
In a race case, EXPLAIN ANALYZE could fail to display correct nbatch
and size information. Refactor so that participants report only on
batches they worked on rather than trying to report on all of them,
and teach explain.c to consider the HashInstrumentation object from
all participants instead of picking the first one it can find. This
should fix an occasional build farm failure in the "join" regression
test.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/30219.1514428346%40sss.pgh.pa.us
Hash index depends on estimation of numbers of tuples and pages of relations,
incorrect value could be a reason of significantly growing of index. Vacuum
full recreates heap and reindex all indexes before renewal stats. The patch
fixes that, so indexes will see correct values.
Backpatch to v10 only because earlier versions haven't usable hash index and
growing of hash index is a single user-visible symptom.
Author: Amit Kapila
Reviewed-by: Ashutosh Sharma, me
Discussion: https://www.postgresql.org/message-id/flat/20171115232922.5tomkxnw3iq6jsg7@inml.weebeastie.net
This patch does three interrelated things:
* Create a new expression execution step type EEOP_PARAM_CALLBACK
and add the infrastructure needed for add-on modules to generate that.
As discussed, the best control mechanism for that seems to be to add
another hook function to ParamListInfo, which will be called by
ExecInitExpr if it's supplied and a PARAM_EXTERN Param is found.
For stand-alone expressions, we add a new entry point to allow the
ParamListInfo to be specified directly, since it can't be retrieved
from the parent plan node's EState.
* Redesign the API for the ParamListInfo paramFetch hook so that the
ParamExternData array can be entirely virtual. This also lets us get rid
of ParamListInfo.paramMask, instead leaving it to the paramFetch hook to
decide which param IDs should be accessible or not. plpgsql_param_fetch
was already doing the identical masking check, so having callers do it too
seemed redundant. While I was at it, I added a "speculative" flag to
paramFetch that the planner can specify as TRUE to avoid unwanted failures.
This solves an ancient problem for plpgsql that it couldn't provide values
of non-DTYPE_VAR variables to the planner for fear of triggering premature
"record not assigned yet" or "field not found" errors during planning.
* Rework plpgsql to get rid of the need for "unshared" parameter lists,
by dint of turning the single ParamListInfo per estate into a nearly
read-only data structure that doesn't instantiate any per-variable data.
Instead, the paramFetch hook controls access to per-variable data and can
make the right decisions on the fly, replacing the cases that we used to
need multiple ParamListInfos for. This might perhaps have been a
performance loss on its own, but by using a paramCompile hook we can
bypass plpgsql_param_fetch entirely during normal query execution.
(It's now only called when, eg, we copy the ParamListInfo into a cursor
portal. copyParamList() or SerializeParamList() effectively instantiate
the virtual parameter array as a simple physical array without a
paramFetch hook, which is what we want in those cases.) This allows
reverting most of commit 6c82d8d1f, though I kept the cosmetic
code-consolidation aspects of that (eg the assign_simple_var function).
Performance testing shows this to be at worst a break-even change,
and it can provide wins ranging up to 20% in test cases involving
accesses to fields of "record" variables. The fact that values of
such variables can now be exposed to the planner might produce wins
in some situations, too, but I've not pursued that angle.
In passing, remove the "parent" pointer from the arguments to
ExecInitExprRec and related functions, instead storing that pointer in a
transient field in ExprState. The ParamListInfo pointer for a stand-alone
expression is handled the same way; we'd otherwise have had to add
yet another recursively-passed-down argument in expression compilation.
Discussion: https://postgr.es/m/32589.1513706441@sss.pgh.pa.us
The previous commit has shown that the sanity checks around freezing
aren't strong enough. Strengthening them seems especially important
because the existance of the bug has caused corruption that we don't
want to make even worse during future vacuum cycles.
The errors are emitted with ereport rather than elog, despite being
"should never happen" messages, so a proper error code is emitted. To
avoid superflous translations, mark messages as internal.
Author: Andres Freund and Alvaro Herrera
Reviewed-By: Alvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
Backpatch: 9.3-
This patch makes a number of interrelated changes to reduce the overhead
involved in creating/deleting memory contexts. The key ideas are:
* Include the AllocSetContext header of an aset.c context in its first
malloc request, rather than allocating it separately in TopMemoryContext.
This means that we now always create an initial or "keeper" block in an
aset, even if it never receives any allocation requests.
* Create freelists in which we can save and recycle recently-destroyed
asets (this idea is due to Robert Haas).
* In the common case where the name of a context is a constant string,
just store a pointer to it in the context header, rather than copying
the string.
The first change eliminates a palloc/pfree cycle per context, and
also avoids bloat in TopMemoryContext, at the price that creating
a context now involves a malloc/free cycle even if the context never
receives any allocations. That would be a loser for some common
usage patterns, but recycling short-lived contexts via the freelist
eliminates that pain.
Avoiding copying constant strings not only saves strlen() and strcpy()
overhead, but is an essential part of the freelist optimization because
it makes the context header size constant. Currently we make no
attempt to use the freelist for contexts with non-constant names.
(Perhaps someday we'll need to think harder about that, but in current
usage, most contexts with custom names are long-lived anyway.)
The freelist management in this initial commit is pretty simplistic,
and we might want to refine it later --- but in common workloads that
will never matter because the freelists will never get full anyway.
To create a context with a non-constant name, one is now required to
call AllocSetContextCreateExtended and specify the MEMCONTEXT_COPY_NAME
option. AllocSetContextCreate becomes a wrapper macro, and it includes
a test that will complain about non-string-literal context name
parameters on gcc and similar compilers.
An unfortunate side effect of making AllocSetContextCreate a macro is
that one is now *required* to use the size parameter abstraction macros
(ALLOCSET_DEFAULT_SIZES and friends) with it; the pre-9.6 habit of
writing out individual size parameters no longer works unless you
switch to AllocSetContextCreateExtended.
Internally to the memory-context-related modules, the context creation
APIs are simplified, removing the rather baroque original design whereby
a context-type module called mcxt.c which then called back into the
context-type module. That saved a bit of code duplication, but not much,
and it prevented context-type modules from exercising control over the
allocation of context headers.
In passing, I converted the test-and-elog validation of aset size
parameters into Asserts to save a few more cycles. The original thought
was that callers might compute size parameters on the fly, but in practice
nobody does that, so it's useless to expend cycles on checking those
numbers in production builds.
Also, mark the memory context method-pointer structs "const",
just for cleanliness.
Discussion: https://postgr.es/m/2264.1512870796@sss.pgh.pa.us
A COPY into a table should apply identity sequence values just like it
does for ordinary defaults. This was previously forgotten, leading to
null values being inserted, which in turn would fail because identity
columns have not-null constraints.
Author: Michael Paquier <michael.paquier@gmail.com>
Reported-by: Steven Winfield <steven.winfield@cantabcapital.com>
Bug: #14952
If a hash join appears in a parallel query, there may be no hash table
available for explain.c to inspect even though a hash table may have
been built in other processes. This could happen either because
parallel_leader_participation was set to off or because the leader
happened to hit the end of the outer relation immediately (even though
the complete relation is not empty) and decided not to build the hash
table.
Commit bf11e7ee introduced a way for workers to exchange
instrumentation via the DSM segment for Sort nodes even though they
are not parallel-aware. This commit does the same for Hash nodes, so
that explain.c has a way to find instrumentation data from an
arbitrary participant that actually built the hash table.
Author: Thomas Munro
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm%3D3DUQC2-z252N55eOcZBer6DPdM%3DFzrxH9dZc5vYLsjaA%40mail.gmail.com
Hopefully, the additional logging will help avoid confusion that
could otherwise result.
Nathan Bossart, reviewed by Michael Paquier, Fabrízio Mello, and me
This adds a new object type "procedure" that is similar to a function
but does not have a return type and is invoked by the new CALL statement
instead of SELECT or similar. This implementation is aligned with the
SQL standard and compatible with or similar to other SQL implementations.
This commit adds new commands CALL, CREATE/ALTER/DROP PROCEDURE, as well
as ALTER/DROP ROUTINE that can refer to either a function or a
procedure (or an aggregate function, as an extension to SQL). There is
also support for procedures in various utility commands such as COMMENT
and GRANT, as well as support in pg_dump and psql. Support for defining
procedures is available in all the languages supplied by the core
distribution.
While this commit is mainly syntax sugar around existing functionality,
future features will rely on having procedures as a separate object
type.
Reviewed-by: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
heap_drop_with_catalog and ATExecDetachPartition neglected to check for
SearchSysCache failures, as noted in bugs #14927 and #14928 from Pan Bian.
Such failures are pretty unlikely, since we should already have some sort
of lock on the rel at these points, but it's neither a good idea nor
per project style to omit a check for failure.
Also, StorePartitionKey contained a syscache lookup that it never did
anything with, including never releasing the result. Presumably the
reason why we don't see refcount-leak complaints is that the lookup
always fails; but in any case it's pretty useless, so remove it.
All of these errors were evidently introduced by the relation
partitioning feature. Back-patch to v10 where that came in.
Amit Langote and Tom Lane
Discussion: https://postgr.es/m/20171127090105.1463.3962@wrigleys.postgresql.org
Discussion: https://postgr.es/m/20171127091341.1468.72696@wrigleys.postgresql.org
If a PARAM_EXEC parameter is used below a Gather (Merge) but the InitPlan
that computes it is attached to or above the Gather (Merge), force the
value to be computed before starting parallelism and pass it down to all
workers. This allows us to use parallelism in cases where it previously
would have had to be rejected as unsafe. We do - in this case - lose the
optimization that the value is only computed if it's actually used. An
alternative strategy would be to have the first worker that needs the value
compute it, but one downside of that approach is that we'd then need to
select a parallel-safe path to compute the parameter value; it couldn't for
example contain a Gather (Merge) node. At some point in the future, we
might want to consider both approaches.
Independent of that consideration, there is a great deal more work that
could be done to make more kinds of PARAM_EXEC parameters parallel-safe.
This infrastructure could be used to allow a Gather (Merge) on the inner
side of a nested loop (although that's not a very appealing plan) and
cases where the InitPlan is attached below the Gather (Merge) could be
addressed as well using various techniques. But this is a good start.
Amit Kapila, reviewed and revised by me. Reviewing and testing from
Kuntal Ghosh, Haribabu Kommi, and Tushar Ahuja.
Discussion: http://postgr.es/m/CAA4eK1LV0Y1AUV4cUCdC+sYOx0Z0-8NAJ2Pd9=UKsbQ5Sr7+JQ@mail.gmail.com
Some code is moved from partition.c, which has grown very quickly lately;
splitting the executor parts out might help to keep it from getting
totally out of control. Other code is moved from execMain.c. All is
moved to a new file execPartition.c. get_partition_for_tuple now has
a new interface that more clearly separates executor concerns from
generic concerns.
Amit Langote. A slight comment tweak by me.
Discussion: http://postgr.es/m/1f0985f8-3b61-8bc4-4350-baa6d804cb6d@lab.ntt.co.jp
Instead of passing large swaths of boolean arguments, define some flags
that can be used in a bitmask. This makes it easier not only to figure
out what each call site is doing, but also to add some new flags.
The flags are split in two -- one set for index_create directly and
another for constraints. index_create() itself receives both, and then
passes down the latter to index_constraint_create(), which can also be
called standalone.
Discussion: https://postgr.es/m/20171023151251.j75uoe27gajdjmlm@alvherre.pgsql
Reviewed-by: Simon Riggs
Hash partitioning is useful when you want to partition a growing data
set evenly. This can be useful to keep table sizes reasonable, which
makes maintenance operations such as VACUUM faster, or to enable
partition-wise join.
At present, we still depend on constraint exclusion for partitioning
pruning, and the shape of the partition constraints for hash
partitioning is such that that doesn't work. Work is underway to fix
that, which should both improve performance and make partitioning
pruning work with hash partitioning.
Amul Sul, reviewed and tested by Dilip Kumar, Ashutosh Bapat, Yugo
Nagata, Rajkumar Raghuwanshi, Jesper Pedersen, and by me. A few
final tweaks also by me.
Discussion: http://postgr.es/m/CAAJ_b96fhpJAP=ALbETmeLk1Uni_GFZD938zgenhF49qgDTjaQ@mail.gmail.com
The lower case spellings are C and C++ standard and are used in most
parts of the PostgreSQL sources. The upper case spellings are only used
in some files/modules. So standardize on the standard spellings.
The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so
those are left as is when using those APIs.
In code comments, we use the lower-case spelling for the C concepts and
keep the upper-case spelling for the SQL concepts.
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
It turns out we misdiagnosed what the real problem was. Revert the
previous changes, because they may have worse consequences going
forward. A better fix is forthcoming.
The simplistic test case is kept, though disabled.
Discussion: https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
It's possible for dropping a column, or altering its type, to require
changes in domain CHECK constraint expressions; but the code was
previously only expecting to find dependent table CHECK constraints.
Make the necessary adjustments.
This is a fairly old oversight, but it's a lot easier to encounter
the problem in the context of domains over composite types than it
was before. Given the lack of field complaints, I'm not going to
bother with a back-patch, though I'd be willing to reconsider that
decision if someone does complain.
Patch by me, reviewed by Michael Paquier
Discussion: https://postgr.es/m/30656.1509128130@sss.pgh.pa.us
This is the last major omission in our domains feature: you can now
make a domain over anything that's not a pseudotype.
The major complication from an implementation standpoint is that places
that might be creating tuples of a domain type now need to be prepared
to apply domain_check(). It seems better that unprepared code fail
with an error like "<type> is not composite" than that it silently fail
to apply domain constraints. Therefore, relevant infrastructure like
get_func_result_type() and lookup_rowtype_tupdesc() has been adjusted
to treat domain-over-composite as a distinct case that unprepared code
won't recognize, rather than just transparently treating it the same
as plain composite. This isn't a 100% solution to the possibility of
overlooked domain checks, but it catches most places.
In passing, improve typcache.c's support for domains (it can now cache
the identity of a domain's base type), and rewrite the argument handling
logic in jsonfuncs.c's populate_record[set]_worker to reduce duplicative
per-call lookups.
I believe this is code-complete so far as the core and contrib code go.
The PLs need varying amounts of work, which will be tackled in followup
patches.
Discussion: https://postgr.es/m/4206.1499798337@sss.pgh.pa.us
Up to now, there's been hard-wired assumptions that normal aggregates'
final functions never modify their transition states, while ordered-set
aggregates' final functions always do. This has always been a bit
limiting, and in particular it's getting in the way of improving the
built-in ordered-set aggregates to allow merging of transition states.
Therefore, let's introduce catalog and CREATE AGGREGATE infrastructure
that lets the finalfn's behavior be declared explicitly.
There are now three possibilities for the finalfn behavior: it's purely
read-only, it trashes the transition state irrecoverably, or it changes
the state in such a way that no more transfn calls are possible but the
state can still be passed to other, compatible finalfns. There are no
examples of this third case today, but we'll shortly make the built-in
OSAs act like that.
This change allows user-defined aggregates to explicitly disclaim support
for use as window functions, and/or to prevent transition state merging,
if their implementations cannot handle that. While it was previously
possible to handle the window case with a run-time error check, there was
not any way to prevent transition state merging, which in retrospect is
something commit 804163bc2 should have provided for. But better late
than never.
In passing, split out pg_aggregate.c's extern function declarations into
a new header file pg_aggregate_fn.h, similarly to what we've done for
some other catalog headers, so that pg_aggregate.h itself can be safe
for frontend files to include. This lets pg_dump use the symbolic
names for relevant constants.
Discussion: https://postgr.es/m/4834.1507849699@sss.pgh.pa.us
The previous convention doesn't lend itself to creating ResultRelInfos
lazily, as we already do in ExecGetTriggerResultRel. This patch
doesn't make anything lazier than before, but the pending patch for
UPDATE tuple routing proposes to do so (and there might be other
opportunities as well).
Amit Khandekar with some adjustments by me.
Discussion: http://postgr.es/m/CA+TgmoYPVP9Lyf6vUFA5DwxS4c--x6LOj2y36BsJaYtp62eXPQ@mail.gmail.com
resowner/README contained advice to use a PG_TRY block to restore the
old CurrentResourceOwner value anywhere that that variable is transiently
changed. That advice was only inconsistently followed, however, and
on reflection it seems like unnecessary overhead. We don't bother
with such a convention for transient CurrentMemoryContext changes,
on the grounds that any (sub)transaction abort will start out by
resetting CurrentMemoryContext to what it wants. But the same is
true of CurrentResourceOwner, so there seems no need to treat it
differently.
Hence, remove PG_TRY blocks that exist only to restore CurrentResourceOwner
before re-throwing the error. There are a couple of places that restore
it along with some other actions, and I left those alone; the restore is
probably unnecessary but no noticeable gain will result from removing it.
Discussion: https://postgr.es/m/5236.1507583529@sss.pgh.pa.us
Up to now async.c has used TransactionIdIsInProgress() to detect whether
a notify message's source transaction is still running. However, that
function has a quick-exit path that reports that XIDs before RecentXmin
are no longer running. If a listening backend is doing nothing but
listening, and not running any queries, there is nothing that will advance
its value of RecentXmin. Once 2 billion transactions elapse, the
RecentXmin check causes active transactions to be reported as not running.
If they aren't committed yet according to CLOG, async.c decides they
aborted and discards their messages. The timing for that is a bit tight
but it can happen when multiple backends are sending notifies concurrently.
The net symptom therefore is that a sufficiently-long-surviving
listen-only backend starts to miss some fraction of NOTIFY traffic,
but only under heavy load.
The only function that updates RecentXmin is GetSnapshotData().
A brute-force fix would therefore be to take a snapshot before
processing incoming notify messages. But that would add cycles,
as well as contention for the ProcArrayLock. We can be smarter:
having taken the snapshot, let's use that to check for running
XIDs, and not call TransactionIdIsInProgress() at all. In this
way we reduce the number of ProcArrayLock acquisitions from one
per message to one per notify interrupt; that's the same under
light load but should be a benefit under heavy load. Light testing
says that this change is a wash performance-wise for normal loads.
I looked around for other callers of TransactionIdIsInProgress()
that might be at similar risk, and didn't find any; all of them
are inside transactions that presumably have already taken a
snapshot.
Problem report and diagnosis by Marko Tiikkaja, patch by me.
Back-patch to all supported branches, since it's been like this
since 9.0.
Discussion: https://postgr.es/m/20170926182935.14128.65278@wrigleys.postgresql.org
If the table attached as a partition is itself partitioned, individual
partitions might have constraints strong enough to skip scanning the
table even if the table actually attached does not. This is pretty
cheap to check, and possibly a big win if it works out.
Amit Langote, with test case changes by me.
Discussion: http://postgr.es/m/1f08b844-0078-aa8d-452e-7af3bf77d05f@lab.ntt.co.jp
Peter Eisentraut
Robert Haas
Andres Freund
Alvaro Herrera
Tom Lane
Noah Misch
Michael Paquier
Tomas Vondra
Heikki Linnakangas
Andrew Dunstan
Bruce Momjian
Peter Eisentraut
Greg Stark
Amit Kapila
Magnus Hagander
Thomas Munro
Alexander Korotkov
Stephen Frost
Tatsuo Ishii
Teodor Sigaev
Simon Riggs
Dean Rasheed