In commit fe0a0b59, the datatype used for MyCancelKey and other variables
that store cancel keys were changed from long to uint32, but I missed this
one. That broke query cancellation on platforms where long is wider than 32
bits.
Report by Andres Freund, fix by Michael Paquier.
Rearrange a bit of code to ensure that 'mode' in LWLockRelease is
obviously always set, which seems a bit cleaner and avoids a compiler
warning (thanks to Robert for the suggestion!).
In GetCachedPlan(), initialize 'plan' to silence a compiler warning, but
also add an Assert() to make sure we don't ever actually fall through
with 'plan' still being set to NULL, since we are about to dereference
it.
Neither of these appear to be live bugs but at least gcc
5.4.0-6ubuntu1~16.04.4 doesn't quite have the smarts to realize that.
Discussion: https://www.postgresql.org/message-id/20161129152102.GR13284%40tamriel.snowman.net
It typically is a "long", but it seems possible that on some platforms
it wouldn't be. In any case, this silences a compiler warning on
OpenBSD (cf buildfarm member curculio).
While at it, use snprintf not sprintf. This format string couldn't
possibly overrun the supplied buffer, but that doesn't seem like
a good reason not to use the safer style.
Oversight in commit f828654e1. Back-patch to 9.6 where that came in.
Previously, a prepared statement created via a Parse message could get
a parallel plan, but one created with a PREPARE statement could not.
This state of affairs was due to confusion on my (rhaas) part: I
erroneously believed that a CREATE TABLE .. AS EXECUTE statement could
only be performed with a prepared statement by PREPARE, but in fact
one created by a Prepare message works just as well. Therefore, it
makes no sense to allow parallel query in one case but not the other.
To fix, allow parallel query with all prepared statements, but run
the parallel plan serially (i.e. without workers) in the case of
CREATE TABLE .. AS EXECUTE. Also, document this.
Amit Kapila and Tobias Bussman, plus an extra sentence of
documentation by me.
The previously code worked OK as long as a Gather node was never
rescanned, or if it was rescanned, as long as it got at least as
many workers on rescan as it had originally. But if the number
of workers ever decreased on a rescan, then it could crash.
Andreas Seltenreich
We have had support for restrictive RLS policies since 9.5, but they
were only available through extensions which use the appropriate hooks.
This adds support into the grammer, catalog, psql and pg_dump for
restrictive RLS policies, thus reducing the cases where an extension is
necessary.
In passing, also move away from using "AND"d and "OR"d in comments.
As pointed out by Alvaro, it's not really appropriate to attempt
to make verbs out of "AND" and "OR", so reword those comments which
attempted to.
Reviewed By: Jeevan Chalke, Dean Rasheed
Discussion: https://postgr.es/m/20160901063404.GY4028@tamriel.snowman.net
It's possible for the metapage contents to change after we release
the lock, so we must read them before releasing the lock.
Amit Kapila. Submitted in response to a trouble report from
Andreas Seltenreich, though it is not certain this fixes the
problem.
Commit b460f5d669 -- at my suggestion --
increased the default value of max_worker_processes from 8 to 16, on
the theory that this would be harmless and convenient for users.
Unfortunately, this caused some buildfarm machines with low connection
limits to start failing, so apparently it's not harmless after all.
On 32-bit systems, don't try to use 64-bit DSA pointers, because the
computation of DSA_MAX_SEGMENT_SIZE overflows Size.
Cast 1 to Size before shifting it, so that the compiler doesn't
produce a result of the wrong width.
In passing, change one use of size_t to Size.
Commit 13df76a537 was overconfident
about how portable %016lx is. Some compilers complain because they
need %016llx, while platforms where DSA pointers are only 32 bits
get unhappy about using a 64-bit format for a 32-bit quantity.
Thomas Munro, per an off-list suggestion from me.
This adds a new routine, pg_strong_random() for generating random bytes,
for use in both frontend and backend. At the moment, it's only used in
the backend, but the upcoming SCRAM authentication patches need strong
random numbers in libpq as well.
pg_strong_random() is based on, and replaces, the existing implementation
in pgcrypto. It can acquire strong random numbers from a number of sources,
depending on what's available:
- OpenSSL RAND_bytes(), if built with OpenSSL
- On Windows, the native cryptographic functions are used
- /dev/urandom
Unlike the current pgcrypto function, the source is chosen by configure.
That makes it easier to test different implementations, and ensures that
we don't accidentally fall back to a less secure implementation, if the
primary source fails. All of those methods are quite reliable, it would be
pretty surprising for them to fail, so we'd rather find out by failing
hard.
If no strong random source is available, we fall back to using erand48(),
seeded from current timestamp, like PostmasterRandom() was. That isn't
cryptographically secure, but allows us to still work on platforms that
don't have any of the above stronger sources. Because it's not very secure,
the built-in implementation is only used if explicitly requested with
--disable-strong-random.
This replaces the more complicated Fortuna algorithm we used to have in
pgcrypto, which is unfortunate, but all modern platforms have /dev/urandom,
so it doesn't seem worth the maintenance effort to keep that. pgcrypto
functions that require strong random numbers will be disabled with
--disable-strong-random.
Original patch by Magnus Hagander, tons of further work by Michael Paquier
and me.
Discussion: https://www.postgresql.org/message-id/CAB7nPqRy3krN8quR9XujMVVHYtXJ0_60nqgVc6oUk8ygyVkZsA@mail.gmail.com
Discussion: https://www.postgresql.org/message-id/CAB7nPqRWkNYRRPJA7-cF+LfroYV10pvjdz6GNvxk-Eee9FypKA@mail.gmail.com
Previously gin_desc() displayed incorrect output "unknown action 0"
for XLOG_GIN_INSERT and XLOG_GIN_VACUUM_DATA_LEAF_PAGE records with
valid actions. The cause of this problem was that gin_desc() wrongly
used XLogRecGetData() to extract data from those records.
Since they were registered by XLogRegisterBufData(), gin_desc() should
have used XLogRecGetBlockData(), instead, like gin_redo().
Also there were other differences about how to treat XLOG_GIN_INSERT
record between gin_desc() and gin_redo().
This commit fixes gin_desc() routine so that it treats those records
in the same way as gin_redo().
Batch-patch to 9.5 where WAL record format was revamped and
XLogRegisterBufData() was added.
Reported-By: Andres Freund
Reviewed-By: Tom Lane
Discussion: <20160509194645.7lewnpw647zegx2m@alap3.anarazel.de>
transformOnConflictClause incremented p_next_resno while generating the
phony targetlist for the EXCLUDED pseudo-rel. Then that field got
incremented some more during transformTargetList, possibly leading to
free_parsestate concluding that we'd overrun the allowed length of a tlist,
as reported by Justin Pryzby.
We could fix this by resetting p_next_resno to 1 after using it for the
EXCLUDED pseudo-rel tlist, but it seems easier and less coupled to other
places if we just don't use that field at all in this loop. (Note that
this doesn't change anything about the resnos that end up appearing in
the main target list, because those are all replaced with target-column
numbers by updateTargetListEntry.)
In passing, fix incorrect type OID assigned to the whole-row Var for
"EXCLUDED.*" (somehow this escaped having any bad consequences so far,
but it's certainly wrong); remove useless assignment to var->location;
pstrdup the column names in case of a relcache flush; and improve
nearby comments.
Back-patch to 9.5 where ON CONFLICT was introduced.
Report: https://postgr.es/m/20161204163237.GA8030@telsasoft.com
deleteWhatDependsOn() had grown an uncomfortably large number of
assumptions about what it's used for. There are actually only two minor
differences between what it does and what a regular performDeletion() call
can do, so let's invent additional bits in performDeletion's existing flags
argument that specify those behaviors, and get rid of deleteWhatDependsOn()
as such. (We'd probably have done it this way from the start, except that
performDeletion didn't originally have a flags argument, IIRC.)
Also, add a SKIP_EXTENSIONS flag bit that prevents ever recursing to an
extension, and use that when dropping temporary objects at session end.
This provides a more general solution to the problem addressed in a hacky
way in commit 08dd23cec: if an extension script creates temp objects and
forgets to remove them again, the whole extension went away when its
contained temp objects were deleted. The previous solution only covered
temp relations, but this solves it for all object types.
These changes require minor additions in dependency.c to pass the flags
to subroutines that previously didn't get them, but it's still a net
savings of code, and it seems cleaner than before.
Having done this, revert the special-case code added in 08dd23cec that
prevented addition of pg_depend records for temp table extension
membership, because that caused its own oddities: dropping an extension
that had created such a table didn't automatically remove the table,
leading to a failure if the table had another dependency on the extension
(such as use of an extension data type), or to a duplicate-name failure if
you then tried to recreate the extension. But we keep the part that
prevents the pg_temp_nnn schema from becoming an extension member; we never
want that to happen. Add a regression test case covering these behaviors.
Although this fixes some arguable bugs, we've heard few field complaints,
and any such problems are easily worked around by explicitly dropping temp
objects at the end of extension scripts (which seems like good practice
anyway). So I won't risk a back-patch.
Discussion: https://postgr.es/m/e51f4311-f483-4dd0-1ccc-abec3c405110@BlueTreble.com
Programmers discovered decades ago that it was useful to have a simple
interface for allocating and freeing memory, which is why malloc() and
free() were invented. Unfortunately, those handy tools don't work
with dynamic shared memory segments because those are specific to
PostgreSQL and are not necessarily mapped at the same address in every
cooperating process. So invent our own allocator instead. This makes
it possible for processes cooperating as part of parallel query
execution to allocate and free chunks of memory without having to
reserve them prior to the start of execution. It could also be used
for longer lived objects; for example, we could consider storing data
for pg_stat_statements or the stats collector in shared memory using
these interfaces, rather than writing them to files. Basically,
anything that needs shared memory but can't predict in advance how
much it's going to need might find this useful.
Thomas Munro and Robert Haas. The original code (of mine) on which
Thomas based his work was actually designed to be a new backend-local
memory allocator for PostgreSQL, but that hasn't gone anywhere - or
not yet, anyway. Thomas took that work and performed major
refactoring and extensive modifications to make it work with dynamic
shared memory, including the addition of appropriate locking.
Discussion: CA+TgmobkeWptGwiNa+SGFWsTLzTzD-CeLz0KcE-y6LFgoUus4A@mail.gmail.com
Discussion: CAEepm=1z5WLuNoJ80PaCvz6EtG9dN0j-KuHcHtU6QEfcPP5-qA@mail.gmail.com
This is intended as infrastructure for a full-fledged allocator for
dynamic shared memory. The interface looks a bit like a real
allocator, but only supports allocating and freeing memory in
multiples of the 4kB page size. Further, to free memory, you must
know the size of the span you wish to free, in pages. While these are
make it unsuitable as an allocator in and of itself, it still serves
as very useful scaffolding for a full-fledged allocator.
Robert Haas and Thomas Munro. This code is mostly the same as my 2014
submission, but Thomas fixed quite a few bugs and made some changes to
the interface.
Discussion: CA+TgmobkeWptGwiNa+SGFWsTLzTzD-CeLz0KcE-y6LFgoUus4A@mail.gmail.com
Discussion: CAEepm=1z5WLuNoJ80PaCvz6EtG9dN0j-KuHcHtU6QEfcPP5-qA@mail.gmail.com
Increase the default value of the existing max_worker_processes GUC
from 8 to 16, and add a new max_parallel_workers GUC with a maximum
of 8. This way, even if the maximum amount of parallel query is
happening, there is still room for background workers that do other
things, as originally envisioned when max_worker_processes was added.
Julien Rouhaud, reviewed by Amit Kapila and by revised by me.
Our documentation states that our maximum field size is 1 GB, and that
our maximum row size of 1.6 TB. However, while this might be attainable
in theory with enough contortions, it is not workable in practice; for
starters, pg_dump fails to dump tables containing rows larger than 1 GB,
even if individual columns are well below the limit; and even if one
does manage to manufacture a dump file containing a row that large, the
server refuses to load it anyway.
This commit enables dumping and reloading of such tuples, provided two
conditions are met:
1. no single column is larger than 1 GB (in output size -- for bytea
this includes the formatting overhead)
2. the whole row is not larger than 2 GB
There are three related changes to enable this:
a. StringInfo's API now has two additional functions that allow creating
a string that grows beyond the typical 1GB limit (and "long" string).
ABI compatibility is maintained. We still limit these strings to 2 GB,
though, for reasons explained below.
b. COPY now uses long StringInfos, so that pg_dump doesn't choke
trying to emit rows longer than 1GB.
c. heap_form_tuple now uses the MCXT_ALLOW_HUGE flag in its allocation
for the input tuple, which means that large tuples are accepted on
input. Note that at this point we do not apply any further limit to the
input tuple size.
The main reason to limit to 2 GB is that the FE/BE protocol uses 32 bit
length words to describe each row; and because the documentation is
ambiguous on its signedness and libpq does consider it signed, we cannot
use the highest-order bit. Additionally, the StringInfo API uses "int"
(which is 4 bytes wide in most platforms) in many places, so we'd need
to change that API too in order to improve, which has lots of fallout.
Backpatch to 9.5, which is the oldest that has
MemoryContextAllocExtended, a necessary piece of infrastructure. We
could apply to 9.4 with very minimal additional effort, but any further
than that would require backpatching "huge" allocations too.
This is the largest set of changes we could find that can be
back-patched without breaking compatibility with existing systems.
Fixing a bigger set of problems (for example, dumping tuples bigger than
2GB, or dumping fields bigger than 1GB) would require changing the FE/BE
protocol and/or changing the StringInfo API in an ABI-incompatible way,
neither of which would be back-patchable.
Authors: Daniel Vérité, Álvaro Herrera
Reviewed by: Tomas Vondra
Discussion: https://postgr.es/m/20160229183023.GA286012@alvherre.pgsql
The whole walreceiver API is now wrapped into a struct, like most of our
other loadable module APIs. The libpq connection is no longer a global
variable in libpqwalreceiver. Instead, it is encapsulated into a struct
that is passed around the functions. This allows multiple walreceivers
to run at the same time.
Add some rudimentary support for logical replication connections to
libpqwalreceiver.
These changes are mostly cosmetic and are going to be useful for the
future logical replication patches.
From: Petr Jelinek <petr@2ndquadrant.com>
Replace use of poll()/select() by WaitLatchOrSocket(), which is more
portable and flexible.
Also change walreceiver to use its procLatch instead of a custom latch.
From: Petr Jelinek <petr@2ndquadrant.com>
This works like function_with_argtypes, but aggregates allow slightly
different arguments.
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
It was apparently added for use by GRANT/REVOKE, but move it closer to
where other function signature related things are kept.
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Instead of sometimes referring to a function signature like func_name
func_args, use the existing function_with_argtypes symbol, which
combines the two.
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
So far the hashtable stored representative tuples in the form of its
input slot, with all columns in the hashtable that are not
needed (i.e. not grouped upon or functionally dependent) set to NULL.
Thats good for saving memory, but it turns out that having tuples full
of NULL isn't free. slot_deform_tuple is faster if there's no NULL
bitmap even if no NULLs are encountered, and skipping over leading NULLs
isn't free.
So compute a separate tuple descriptor that only contains the needed
columns. As columns have already been moved in/out the slot for the
hashtable that does not imply additional per-row overhead.
Author: Andres Freund
Reviewed-By: Heikki Linnakangas
Discussion: https://postgr.es/m/20161103110721.h5i5t5saxfk5eeik@alap3.anarazel.de
Previously we did a ExecProject() for each individual aggregate
argument. That turned out to be a performance bottleneck in queries with
multiple aggregates.
Doing all the argument computations in one ExecProject() is quite a bit
cheaper because ExecProject's fastpath can do the work at once in a
relatively tight loop, and because it can get all the required columns
with a single slot_getsomeattr and save some other redundant setup
costs.
Author: Andres Freund
Reviewed-By: Heikki Linnakangas
Discussion: https://postgr.es/m/20161103110721.h5i5t5saxfk5eeik@alap3.anarazel.de
Previously, the right to split a bucket was represented by a
heavyweight lock on the page number of the primary bucket page.
Unfortunately, this meant that every scan needed to take a heavyweight
lock on that bucket also, which was bad for concurrency. Instead, use
a cleanup lock on the primary bucket page to indicate the right to
begin a split, so that scans only need to retain a pin on that page,
which is they would have to acquire anyway, and which is also much
cheaper.
In addition to reducing the locking cost, this also avoids locking out
scans and inserts for the entire lifetime of the split: while the new
bucket is being populated with copies of the appropriate tuples from
the old bucket, scans and inserts can happen in parallel. There are
minor concurrency improvements for vacuum operations as well, though
the situation there is still far from ideal.
This patch also removes the unworldly assumption that a split will
never be interrupted. With the new code, a split is done in a series
of small steps and the system can pick up where it left off if it is
interrupted prior to completion. While this patch does not itself add
write-ahead logging for hash indexes, it is clearly a necessary first
step, since one of the things that could interrupt a split is the
removal of electrical power from the machine performing it.
Amit Kapila. I wrote the original design on which this patch is
based, and did a good bit of work on the comments and README through
multiple rounds of review, but all of the code is Amit's. Also
reviewed by Jesper Pedersen, Jeff Janes, and others.
Discussion: http://postgr.es/m/CAA4eK1LfzcZYxLoXS874Ad0+S-ZM60U9bwcyiUZx9mHZ-KCWhw@mail.gmail.com
Generate EUC_CN mappings from gb-18030-2000.xml, because GB2312.TXT is no
longer available.
Get UHC from windows-949-2000.xml, it's more up-to-date.
Plus tons more small changes. With these changes, the perl scripts
faithfully produce the *.map files we have in the repository, from the
external source files.
In the passing, fix the Makefile to also download CP932.TXT and CP950.TXT.
Based on patches by Kyotaro Horiguchi, reviewed by Daniel Gustafsson.
Discussion: https://postgr.es/m/08e7892a-d55c-eefe-76e6-7910bc8dd1f3@iki.fi
The common style is to pad to 4 digits.
Running the current perl scripts to generate these map files would override
this change, but the next commit will rewrite the perl scripts to produce
this style. I'm doing this as a separate commit, to make it more clear what
non-cosmetic changes the next commit makes to the map files.
Discussion: https://postgr.es/m/08e7892a-d55c-eefe-76e6-7910bc8dd1f3@iki.fi
PostgreSQL treats characters with < 0x80 leading byte as plain ASCII, and
they are not even passed to the conversion routines. There is no point in
having them in the conversion tables.
Everything in the tables were direct ASCII-ASCII mappings, except for two:
* SHIFT_JIS_2004 code point 0x5C (backslash in ASCII) was mapped to Unicode
YEN SIGN character.
* Unicode 0x5C (backslash again) was mapped to "REVERSE SOLIDUS" in
SHIFT_JIS_2004
These mappings never had any effect, so there's no functional change from
removing them.
Discussion: https://postgr.es/m/08e7892a-d55c-eefe-76e6-7910bc8dd1f3@iki.fi
consider_parallel_nestloop passed the wrong jointype down to its
subroutines for JOIN_UNIQUE_INNER cases (it should pass JOIN_INNER), and it
thought that it could pass paths other than innerrel->cheapest_total_path
to create_unique_path, which create_unique_path is not on board with.
These bugs would lead to assertion failures or other errors, suggesting
that this code path hasn't been tested much.
hash_inner_and_outer's code for parallel join effectively treated both
JOIN_UNIQUE_OUTER and JOIN_UNIQUE_INNER the same as JOIN_INNER (for
different reasons :-(), leading to incorrect plans that treated a semijoin
as if it were a plain join.
Michael Day submitted a test case demonstrating that hash_inner_and_outer
failed for JOIN_UNIQUE_OUTER, and I found the other cases through code
review.
Report: https://postgr.es/m/D0E8A029-D1AC-42E8-979A-5DE4A77E4413@rcmail.com
If we don't have any MCV statistics for the inner relation, and we don't
trust its numdistinct estimate either, eqjoinsel_semi falls back to a very
conservative estimate (that 50% of the outer rows have matches). This is
particularly problematic if the inner relation is completely empty, since
then even an explicit ANALYZE won't produce any pg_statistic entries,
so there's no way to budge the planner off the bad estimate.
We'd produce a better estimate in such cases if we used the nd2/nd1
selectivity heuristic, so an easy fix is to treat the nd2 estimate as
non-default if we derive it from clamping to the inner rel's rowcount
estimate. This won't fix every related case (mainly because the rowcount
estimate might be larger than DEFAULT_NUM_DISTINCT), but it seems like a
sane extension of the existing logic, so let's apply the change in HEAD
and see if anyone complains. Per bug #14438 from Nikolay Nikitin.
Report: https://postgr.es/m/20161128182113.6527.58926@wrigleys.postgresql.org
Discussion: https://postgr.es/m/31089.1480384713@sss.pgh.pa.us
Oversight in my commit 0bb51aa96. Noted while poking at a recent
bug report --- HEAD's estimates for a query using CURRENT_DATE
were unexpectedly much worse than 9.6's.
Commit a734fd5d1 exposed some race conditions that existed previously
in the autovac code, but were basically harmless because autovac would
not try to delete orphaned relations immediately. Specifically, the test
for orphaned-ness was made on a pg_class tuple that might be dead by now,
allowing autovac to try to remove a table that the owning backend had just
finished deleting. This resulted in a hard crash due to inadequate caution
about accessing the table's catalog entries without any lock. We must take
a relation lock and then recheck whether the table is still present and
still looks deletable before we do anything.
Also, it seemed to me that deleting multiple tables per transaction, and
trying to continue after errors, represented unjustifiable complexity.
We do not expect this code path to be taken often in the field, nor even
during testing, which means that prioritizing performance over correctness
is a bad tradeoff. Rip all that out in favor of just starting a new
transaction after each successful temp table deletion. If we're unlucky
enough to get an error, which shouldn't happen anyway now that we're being
more cautious, let the autovacuum worker fail as it normally would.
In passing, improve the order of operations in the initial scan loop.
Now that we don't care about whether a temp table is a wraparound hazard,
there's no need to perform extract_autovac_opts, get_pgstat_tabentry_relid,
or relation_needs_vacanalyze for temp tables.
Also, if GetTempNamespaceBackendId returns InvalidBackendId (indicating
it doesn't recognize the schema as temp), treat that as meaning it's NOT
an orphaned temp table, not that it IS one, which is what happened before
because BackendIdGetProc necessarily failed. The case really shouldn't
come up for a table that has RELPERSISTENCE_TEMP, but the consequences
if it did seem undesirable. (This might represent a back-patchable bug
fix; not sure if it's worth the trouble.)
Discussion: https://postgr.es/m/21299.1480272347@sss.pgh.pa.us
Commit 08dd23cec introduced an exception to the rule that extension member
objects can only be dropped as part of dropping the whole extension,
intending to allow such drops while running the extension's own creation or
update scripts. However, the exception was only applied at the outermost
recursion level, because it was modeled on a pre-existing check to ignore
dependencies on objects listed in pendingObjects. Bug #14434 from Philippe
Beaudoin shows that this is inadequate: in some cases we can reach an
extension member object by recursion from another one. (The bug concerns
the serial-sequence case; I'm not sure if there are other cases, but there
might well be.)
To fix, revert 08dd23cec's changes to findDependentObjects() and instead
apply the creating_extension exception regardless of stack level.
Having seen this example, I'm a bit suspicious that the pendingObjects
logic is also wrong and such cases should likewise be allowed at any
recursion level. However, changing that would interact in subtle ways
with the recursion logic (at least it would need to be moved to after the
recursing-from check). Given that the code's been like that a long time,
I'll refrain from touching it without a clear example showing it's wrong.
Back-patch to all active branches. In HEAD and 9.6, where suitable
test infrastructure exists, add a regression test case based on the
bug report.
Report: <20161125151448.6529.33039@wrigleys.postgresql.org>
Discussion: <13224.1480177514@sss.pgh.pa.us>
Instead of confusingly stating platform-dependent defaults for these
parameters in the comments in postgresql.conf.sample (with the main
entry being a lie on Linux), teach initdb to install the correct
platform-dependent value in postgresql.conf, similarly to the way
we handle other platform-dependent defaults. This won't do anything
for existing 9.6 installations, but since it's effectively only a
documentation improvement, that seems OK.
Since this requires initdb to have access to the default values,
move the #define's for those to pg_config_manual.h; the original
placement in bufmgr.h is unworkable because that file can't be
included by frontend programs.
Adjust the default value for wal_writer_flush_after so that it is 1MB
regardless of XLOG_BLCKSZ, conforming to what is stated in both the
SGML docs and postgresql.conf. (We could alternatively make it scale
with XLOG_BLCKSZ, but I'm not sure I see the point.)
Copy-edit related SGML documentation.
Fabien Coelho and Tom Lane, per a gripe from Tomas Vondra.
Discussion: <30ebc6e3-8358-09cf-44a8-578252938424@2ndquadrant.com>
Andreas Seltenreich found another case where we were being too optimistic
about allowing a plan to be considered parallelizable despite it containing
initPlans. It seems like the real issue here is that if we know we are
going to tack initPlans onto the topmost Plan node for a subquery, we
had better mark that subquery's result Paths as not-parallel-safe. That
fixes this problem and allows reversion of a kluge (added in commit
7b67a0a49 and extended in f24cf960d) to not trust the parallel_safe flag
at top level.
Discussion: <874m2w4k5d.fsf@ex.ansel.ydns.eu>
When dropping a foreign key constraint with ALTER TABLE DROP CONSTRAINT,
we refuse the drop if there are any pending trigger events on the named
table; this ensures that we won't remove the pg_trigger row that will be
consulted by those events. But we should make the same check for the
referenced relation, else we might remove a due-to-be-referenced pg_trigger
row for that relation too, resulting in "could not find trigger NNN" or
"relation NNN has no triggers" errors at commit. Per bug #14431 from
Benjie Gillam. Back-patch to all supported branches.
Report: <20161124114911.6530.31200@wrigleys.postgresql.org>
Previously, requesting commit timestamp for transactions
FrozenTransactionId and BootstrapTransactionId resulted in an error.
But since those values can validly appear in committed tuples' Xmin,
this behavior is unhelpful and error prone: each caller would have to
special-case those values before requesting timestamp data for an Xid.
We already have a perfectly good interface for returning "the Xid you
requested is too old for us to have commit TS data for it", so let's use
that instead.
Backpatch to 9.5, where commit timestamps appeared.
Author: Craig Ringer
Discussion: https://www.postgresql.org/message-id/CAMsr+YFM5Q=+ry3mKvWEqRTxrB0iU3qUSRnS28nz6FJYtBwhJg@mail.gmail.com
When rebuilding an existing index, ALTER TABLE correctly kept the
physical file in the same tablespace, but it messed up the pg_class
entry if the index had been in the database's default tablespace
and "default_tablespace" was set to some non-default tablespace.
This led to an inaccessible index.
Fix by fixing pg_get_indexdef_string() to always include a tablespace
clause, whether or not the index is in the default tablespace. The
previous behavior was installed in commit 537e92e41, and I think it just
wasn't thought through very clearly; certainly the possible effect of
default_tablespace wasn't considered. There's some risk in changing the
behavior of this function, but there are no other call sites in the core
code. Even if it's being used by some third party extension, it's fairly
hard to envision a usage that is okay with a tablespace clause being
appended some of the time but can't handle it being appended all the time.
Back-patch to all supported versions.
Code fix by me, investigation and test cases by Michael Paquier.
Discussion: <1479294998857-5930602.post@n3.nabble.com>
A new thing also called a "barrier" is proposed, but whether we decide
to take that patch or not, this file seems to have outlived its
usefulness.
Thomas Munro
Heikki Linnakangas
Stephen Frost
Tom Lane
Robert Haas
Fujii Masao
Alvaro Herrera
Peter Eisentraut
Andres Freund
Magnus Hagander