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  1. 03 Sep, 2021 3 commits
    • Tom Lane's avatar
      Disallow creating an ICU collation if the DB encoding won't support it. · 2cc018ba
      Tom Lane authored 
      Previously this was allowed, but the collation effectively vanished
into the ether because of the way lookup_collation() works: you could
not use the collation, nor even drop it.  Seems better to give an
error up front than to leave the user wondering why it doesn't work.

(Because this test is in DefineCollation not CreateCollation, it does
not prevent pg_import_system_collations from creating ICU collations,
regardless of the initially-chosen encoding.)

Per bug #17170 from Andrew Bille.  Back-patch to v10 where ICU support
was added.

Discussion: https://postgr.es/m/17170-95845cf3f0a9c36d@postgresql.org
      2cc018ba
    • John Naylor's avatar
      Set the volatility of the timestamptz version of date_bin() back to immutable · 67c33a11
      John Naylor authored 
      543f36b43d was too hasty in thinking that the volatility of date_bin()
had to match date_trunc(), since only the latter references
session_timezone.

Bump catversion

Per feedback from Aleksander Alekseev
Backpatch to v14, as the former commit was
      67c33a11
    • Tom Lane's avatar
      Fix portability issue in tests from commit ce773f230. · 08b96a2b
      Tom Lane authored 
      Modern POSIX seems to require strtod() to accept "-NaN", but there's
nothing about NaN in SUSv2, and some of our oldest buildfarm members
don't like it.  Let's try writing it as -'NaN' instead; that seems
to produce the same result, at least on Intel hardware.

Per buildfarm.
      08b96a2b
  3. 02 Sep, 2021 3 commits
    • Tom Lane's avatar
      In count_usable_fds(), duplicate stderr not stdin. · 6b54f123
      Tom Lane authored 
      We had a complaint that the postmaster fails to start if the invoking
program closes stdin.  That happens because count_usable_fds expects
to be able to dup(0), and if it can't, we conclude there are no free
FDs and go belly-up.  So far as I can find, though, there is no other
place in the server that touches stdin, and it's not unreasonable to
expect that a daemon wouldn't use that file.

As a simple improvement, let's dup FD 2 (stderr) instead.  Unlike stdin,
it *is* reasonable for us to expect that stderr be open; even if we are
configured not to touch it, common libraries such as libc might try to
write error messages there.

Per gripe from Mario Emmenlauer.  Given the lack of previous complaints,
I'm not excited about pushing this into stable branches, but it seems
OK to squeeze it into v14.

Discussion: https://postgr.es/m/48bafc63-c30f-3962-2ded-f2e985d93e86@emmenlauer.de
      6b54f123
    • Tom Lane's avatar
      Fix float4/float8 hash functions to produce uniform results for NaNs. · 23c6bc58
      Tom Lane authored 
      The IEEE 754 standard allows a wide variety of bit patterns for NaNs,
of which at least two ("NaN" and "-NaN") are pretty easy to produce
from SQL on most machines.  This is problematic because our btree
comparison functions deem all NaNs to be equal, but our float hash
functions know nothing about NaNs and will happily produce varying
hash codes for them.  That causes unexpected results from queries
that hash a column containing different NaN values.  It could also
produce unexpected lookup failures when using a hash index on a
float column, i.e. "WHERE x = 'NaN'" will not find all the rows
it should.

To fix, special-case NaN in the float hash functions, not too much
unlike the existing special case that forces zero and minus zero
to hash the same.  I arranged for the most vanilla sort of NaN
(that coming from the C99 NAN constant) to still have the same
hash code as before, to reduce the risk to existing hash indexes.

I dithered about whether to back-patch this into stable branches,
but ultimately decided to do so.  It's a clear improvement for
queries that hash internally.  If there is anybody who has -NaN
in a hash index, they'd be well advised to re-index after applying
this patch ... but the misbehavior if they don't will not be much
worse than the misbehavior they had before.

Per bug #17172 from Ma Liangzhu.

Discussion: https://postgr.es/m/17172-7505bea9e04e230f@postgresql.org
      23c6bc58
    • Michael Paquier's avatar
      doc: Replace some uses of "which" by "that" in parallel.sgml · 2c1981ec
      Michael Paquier authored 
      This makes the documentation more accurate grammatically.

Author: Elena Indrupskaya
Discussion: https://postgr.es/m/1c994b3d-951e-59bb-1ac2-7b9221c0e4cf@postgrespro.ru
Backpatch-through: 9.6
      2c1981ec
  5. 01 Sep, 2021 5 commits
    • Tom Lane's avatar
      Doc: clarify how triggers relate to transactions. · 95bc40f8
      Tom Lane authored 
      Laurenz Albe, per gripe from Nathan Long.

Discussion: https://postgr.es/m/161953360822.695.15805897835151971142@wrigleys.postgresql.org
      95bc40f8
    • Tomas Vondra's avatar
      Identify simple column references in extended statistics · 50ba70a9
      Tomas Vondra authored 
      Until now, when defining extended statistics, everything except a plain
column reference was treated as complex expression. So for example "a"
was a column reference, but "(a)" would be an expression. In most cases
this does not matter much, but there were a couple strange consequences.
For example

    CREATE STATISTICS s ON a FROM t;

would fail, because extended stats require at least two columns. But

    CREATE STATISTICS s ON (a) FROM t;

would succeed, because that requirement does not apply to expressions.
Moreover, that statistics object is useless - the optimizer will always
use the regular statistics collected for attribute "a".

So do a bit more work to identify those expressions referencing a single
column, and translate them to a simple column reference. Backpatch to
14, where support for extended statistics on expressions was introduced.

Reported-by: Justin Pryzby
Backpatch-through: 14
Discussion: https://postgr.es/m/20210816013255.GS10479%40telsasoft.com
      50ba70a9
    • Fujii Masao's avatar
      pgbench: Fix bug in measurement of disconnection delays. · d760d942
      Fujii Masao authored 
      When -C/--connect option is specified, pgbench establishes and closes
the connection for each transaction. In this case pgbench needs to
measure the times taken for all those connections and disconnections,
to include the average connection time in the benchmark result.
But previously pgbench could not measure those disconnection delays.
To fix the bug, this commit makes pgbench measure the disconnection
delays whenever the connection is closed at the end of transaction,
if -C/--connect option is specified.

Back-patch to v14. Per discussion, we concluded not to back-patch to v13
or before because changing that behavior in stable branches would
surprise users rather than providing benefits.

Author: Yugo Nagata
Reviewed-by: Fabien COELHO, Tatsuo Ishii, Asif Rehman, Fujii Masao
Discussion: https://postgr.es/m/20210614151155.a393bc7d8fed183e38c9f52a@sraoss.co.jp
      d760d942
    • Amit Kapila's avatar
      Fix the random test failure in 001_rep_changes. · b7ad093d
      Amit Kapila authored 
      The check to test whether the subscription workers were restarting after a
change in the subscription was failing. The reason was that the test was
assuming the walsender started before it reaches the 'streaming' state and
the walsender was exiting due to an error before that. Now, the walsender
was erroring out before reaching the 'streaming' state because it tries to
acquire the slot before the previous walsender has exited.

In passing, improve the die messages so that it is easier to investigate
the failures in the future if any.

Reported-by: Michael Paquier, as per buildfarm
Author: Ajin Cherian
Reviewed-by: Masahiko Sawada, Amit Kapila
Backpatch-through: 10, where this test was introduced
Discussion: https://postgr.es/m/YRnhFxa9bo73wfpV@paquier.xyz
      b7ad093d
    • Peter Geoghegan's avatar
      VACUUM VERBOSE: Don't report "pages removed". · 0d892cf7
      Peter Geoghegan authored 
      It doesn't make any sense to report this information, since VACUUM
VERBOSE reports on heap relation truncation directly.  This was an
oversight in commit 7ab96cf6, which made VACUUM VERBOSE output a little
more consistent with nearby autovacuum-specific log output.  Adjust
comments that describe how this is supposed to work in passing.

Also bring truncation-related VACUUM VERBOSE output in line with the
convention established for VACUUM VERBOSE output by commit f4f4a649.

Author: Peter Geoghegan <pg@bowt.ie>
Backpatch: 14-, where VACUUM VERBOSE's output changed.
      0d892cf7
  7. 31 Aug, 2021 7 commits
    • Tomas Vondra's avatar
      Don't print extra parens around expressions in extended stats · 4d1816ec
      Tomas Vondra authored 
      The code printing expressions for extended statistics doubled the
parens, producing results like ((a+1)), which is unnecessary and not
consistent with how we print expressions elsewhere.

Fixed by tweaking the code to produce just a single set of parens.

Reported by Mark Dilger, fix by me. Backpatch to 14, where support for
extended statistics on expressions was added.

Reported-by: Mark Dilger
Discussion: https://postgr.es/m/20210122040101.GF27167%40telsasoft.com
      4d1816ec
    • John Naylor's avatar
      Mark the timestamptz variant of date_bin() as stable · 3eda9fc0
      John Naylor authored 
      Previously, it was immutable by lack of marking. This is not
correct, since the time zone could change.

Bump catversion

Discussion: https://www.postgresql.org/message-id/CAFBsxsG2UHk8mOWL0tca%3D_cg%2B_oA5mVRNLhDF0TBw980iOg5NQ%40mail.gmail.com
Backpatch to v14, when this function came in
      3eda9fc0
    • Tom Lane's avatar
      In pg_dump, avoid doing per-table queries for RLS policies. · a20a9f26
      Tom Lane authored 
      For no particularly good reason, getPolicies() queried pg_policy
separately for each table.  We can collect all the policies in
a single query instead, and attach them to the correct TableInfo
objects using findTableByOid() lookups.  On the regression
database, this reduces the number of queries substantially, and
provides a visible savings even when running against a local
server.

Per complaint from Hubert Depesz Lubaczewski.  Since this is such
a simple fix and can have a visible performance benefit, back-patch
to all supported branches.

Discussion: https://postgr.es/m/20210826084430.GA26282@depesz.com
      a20a9f26
    • Tom Lane's avatar
      Cache the results of format_type() queries in pg_dump. · 9407dbbc
      Tom Lane authored 
      There's long been a "TODO: there might be some value in caching
the results" annotation on pg_dump's getFormattedTypeName function;
but we hadn't gotten around to checking what it was costing us to
repetitively look up type names.  It turns out that when dumping the
current regression database, about 10% of the total number of queries
issued are duplicative format_type() queries.  However, Hubert Depesz
Lubaczewski reported a not-unusual case where these account for over
half of the queries issued by pg_dump.  Individually these queries
aren't expensive, but when network lag is a factor, they add up to a
problem.  We can very easily add some caching to getFormattedTypeName
to solve it.

Since this is such a simple fix and can have a visible performance
benefit, back-patch to all supported branches.

Discussion: https://postgr.es/m/20210826084430.GA26282@depesz.com
      9407dbbc
    • Tomas Vondra's avatar
      Rename the role in stats_ext to have regress_ prefix · 4090ff2a
      Tomas Vondra authored 
      Commit 5be8ce82e8 added a new role to the stats_ext regression suite,
but the role name did not start with regress_ causing failures when
running with ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS. Fixed by
renaming the role to start with the expected regress_ prefix.

Backpatch-through: 10, same as the new regression test
Discussion: https://postgr.es/m/1F238937-7CC2-4703-A1B1-6DC225B8978A%40enterprisedb.com
      4090ff2a
    • Tomas Vondra's avatar
      Fix lookup error in extended stats ownership check · a371a5ba
      Tomas Vondra authored 
      When an ownership check on extended statistics object failed, the code
was calling aclcheck_error_type to report the failure, which is clearly
wrong, resulting in cache lookup errors. Fix by calling aclcheck_error.

This issue exists since the introduction of extended statistics, so
backpatch all the way back to PostgreSQL 10. It went unnoticed because
there were no tests triggering the error, so add one.

Reported-by: Mark Dilger
Backpatch-through: 10, where extended stats were introduced
Discussion: https://postgr.es/m/1F238937-7CC2-4703-A1B1-6DC225B8978A%40enterprisedb.com
      a371a5ba
    • Tom Lane's avatar
      Fix missed lock acquisition while inlining new-style SQL functions. · 983d7033
      Tom Lane authored 
      When starting to use a query parsetree loaded from the catalogs,
we must begin by applying AcquireRewriteLocks(), to obtain the same
relation locks that the parser would have gotten if the query were
entered interactively, and to do some other cleanup such as dealing
with later-dropped columns.  New-style SQL functions are just as
subject to this rule as other stored parsetrees; however, of the
places dealing with such functions, only init_sql_fcache had gotten
the memo.  In particular, if we successfully inlined a new-style
set-returning SQL function that contained any relation references,
we'd either get an assertion failure or attempt to use those
relation(s) sans locks.

I also added AcquireRewriteLocks calls to fmgr_sql_validator and
print_function_sqlbody.  Desultory experiments didn't demonstrate any
failures in those, but I suspect that I just didn't try hard enough.
Certainly we don't expect nearby code paths to operate without locks.

On the same logic of it-ought-to-have-the-same-effects-as-the-old-code,
call pg_rewrite_query() in fmgr_sql_validator, too.  It's possible
that neither code path there needs to bother with rewriting, but
doing the analysis to prove that is beyond my goals for today.

Per bug #17161 from Alexander Lakhin.

Discussion: https://postgr.es/m/17161-048a1cdff8422800@postgresql.org
      983d7033
  9. 30 Aug, 2021 5 commits
  11. 28 Aug, 2021 4 commits
  13. 27 Aug, 2021 8 commits
  15. 25 Aug, 2021 5 commits
    • Tom Lane's avatar
      Remove redundant test. · ed740b06
      Tom Lane authored 
      The condition "context_start < context_end" is strictly weaker
than "context_end - context_start >= 50", so we don't need both.
Oversight in commit ffd3944a, noted by tanghy.fnst.

In passing, line-wrap a nearby test to make it more readable.

Discussion: https://postgr.es/m/OS0PR01MB61137C4054774F44E3A9DC89FBC69@OS0PR01MB6113.jpnprd01.prod.outlook.com
      ed740b06
    • Robert Haas's avatar
      Fix broken snapshot handling in parallel workers. · 11c12398
      Robert Haas authored 
      Pengchengliu reported an assertion failure in a parallel woker while
performing a parallel scan using an overflowed snapshot. The proximate
cause is that TransactionXmin was set to an incorrect value.  The
underlying cause is incorrect snapshot handling in parallel.c.

In particular, InitializeParallelDSM() was unconditionally calling
GetTransactionSnapshot(), because I (rhaas) mistakenly thought that
was always retrieving an existing snapshot whereas, at isolation
levels less than REPEATABLE READ, it's actually taking a new one. So
instead do this only at higher isolation levels where there actually
is a single snapshot for the whole transaction.

By itself, this is not a sufficient fix, because we still need to
guarantee that TransactionXmin gets set properly in the workers. The
easiest way to do that seems to be to install the leader's active
snapshot as the transaction snapshot if the leader did not serialize a
transaction snapshot. This doesn't affect the results of future
GetTrasnactionSnapshot() calls since those have to take a new snapshot
anyway; what we care about is the side effect of setting TransactionXmin.

Report by Pengchengliu. Patch by Greg Nancarrow, except for some comment
text which I supplied.

Discussion: https://postgr.es/m/002f01d748ac$eaa781a0$bff684e0$@tju.edu.cn
      11c12398
    • Peter Eisentraut's avatar
      Fix typo · a599109e
      Peter Eisentraut authored
      a599109e
    • Michael Paquier's avatar
      Fix incorrect merge in ECPG code with DECLARE · 8ab3452d
      Michael Paquier authored 
      The same condition was repeated twice when comparing the connection used
by existing declared statement with the one coming from a fresh DECLARE
statement.  This had no consequences, but let's keep the code clean.
Oversight in f576de1.

Author: Shenhao Wang
Discussion: https://postgr.es/m/OSBPR01MB42149653BC0AB0A49D23C1B8F2C69@OSBPR01MB4214.jpnprd01.prod.outlook.com
Backpatch-through: 14
      8ab3452d
    • Amit Kapila's avatar
      Fix toast rewrites in logical decoding. · 9d7a80ce
      Amit Kapila authored 
      Commit 325f2ec5 introduced pg_class.relwrite to skip operations on
tables created as part of a heap rewrite during DDL. It links such
transient heaps to the original relation OID via this new field in
pg_class but forgot to do anything about toast tables. So, logical
decoding was not able to skip operations on internally created toast
tables. This leads to an error when we tried to decode the WAL for the
next operation for which it appeared that there is a toast data where
actually it didn't have any toast data.

To fix this, we set pg_class.relwrite for internally created toast tables
as well which allowed skipping operations on them during logical decoding.

Author: Bertrand Drouvot
Reviewed-by: David Zhang, Amit Kapila
Backpatch-through: 11, where it was introduced
Discussion: https://postgr.es/m/b5146fb1-ad9e-7d6e-f980-98ed68744a7c@amazon.com
      9d7a80ce