PostgreSQL 9.6.14 commit log

Stamp 9.6.14.

commit   : 25cd1175fce691517c9e55311d9a1e4ecf930a32    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 17 Jun 2019 17:21:22 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 17 Jun 2019 17:21:22 -0400    

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M configure
M configure.in
M doc/bug.template
M src/include/pg_config.h.win32
M src/interfaces/libpq/libpq.rc.in
M src/port/win32ver.rc

Last-minute updates for release notes.

commit   : 7dc3e28173b6d7527a24bb8a4e324137c7cfe9d2    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 17 Jun 2019 10:53:45 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 17 Jun 2019 10:53:45 -0400    

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Security: CVE-2019-10164  

M doc/src/sgml/release-9.6.sgml

Translation updates

commit   : 37f582fd1c1cfa52e07a37a37857b79cb5ec2fd0    
  
author   : Peter Eisentraut <[email protected]>    
date     : Mon, 17 Jun 2019 14:50:51 +0200    
  
committer: Peter Eisentraut <[email protected]>    
date     : Mon, 17 Jun 2019 14:50:51 +0200    

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Source-Git-URL: https://git.postgresql.org/git/pgtranslation/messages.git  
Source-Git-Hash: 8d40ff585f42323b760cdddbc2bd33ba17f2116a  

M src/backend/po/es.po
M src/bin/initdb/po/de.po
M src/bin/initdb/po/sv.po
M src/bin/pg_dump/po/de.po
M src/bin/scripts/po/de.po

Revert "Avoid spurious deadlocks when upgrading a tuple lock"

commit   : 03964e58efb8cbb8ecf3f4cdd27c8c757c30e89e    
  
author   : Alvaro Herrera <[email protected]>    
date     : Sun, 16 Jun 2019 22:24:20 -0400    
  
committer: Alvaro Herrera <[email protected]>    
date     : Sun, 16 Jun 2019 22:24:20 -0400    

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This reverts commits 3da73d6839dc and de87a084c0a5.  
  
This code has some tricky corner cases that I'm not sure are correct and  
not properly tested anyway, so I'm reverting the whole thing for next  
week's releases (reintroducing the deadlock bug that we set to fix).  
I'll try again afterwards.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/backend/access/heap/README.tuplock
M src/backend/access/heap/heapam.c
D src/test/isolation/expected/tuplelock-upgrade-no-deadlock.out
M src/test/isolation/isolation_schedule
D src/test/isolation/specs/tuplelock-upgrade-no-deadlock.spec

Release notes for 10.9, 9.6.14, 9.5.18, 9.4.23.

commit   : 609445b427229fa0fdca470089d802c6f4a62d4d    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 16 Jun 2019 15:39:08 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 16 Jun 2019 15:39:08 -0400    

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(11.4 notes are already done.)  

M doc/src/sgml/release-9.6.sgml

Prefer timezone name "UTC" over alternative spellings.

commit   : 5f5b6667ebf3ab24327ecb275167709d8d70cece    
  
author   : Andrew Gierth <[email protected]>    
date     : Sat, 15 Jun 2019 18:15:23 +0100    
  
committer: Andrew Gierth <[email protected]>    
date     : Sat, 15 Jun 2019 18:15:23 +0100    

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tzdb 2019a made "UCT" a link to the "UTC" zone rather than a separate  
zone with its own abbreviation. Unfortunately, our code for choosing a  
timezone in initdb has an arbitrary preference for names earlier in  
the alphabet, and so it would choose the spelling "UCT" over "UTC"  
when the system is running on a UTC zone.  
  
Commit 23bd3cec6 was backpatched in order to address this issue, but  
that code helps only when /etc/localtime exists as a symlink, and does  
nothing to help on systems where /etc/localtime is a copy of a zone  
file (as is the standard setup on FreeBSD and probably some other  
platforms too) or when /etc/localtime is simply absent (giving UTC as  
the default).  
  
Accordingly, add a preference for the spelling "UTC", such that if  
multiple zone names have equally good content matches, we prefer that  
name before applying the existing arbitrary rules. Also add a slightly  
lower preference for "Etc/UTC"; lower because that preserves the  
previous behaviour of choosing the shorter name, but letting us still  
choose "Etc/UTC" over "Etc/UCT" when both exist but "UTC" does  
not (not common, but I've seen it happen).  
  
Backpatch all the way, because the tzdb change that sparked this issue  
is in those branches too.  

M src/bin/initdb/findtimezone.c

Silence compiler warning

commit   : 563357a12c9b1cdbae29a2d0d09eb9f2c01da4d6    
  
author   : Alvaro Herrera <[email protected]>    
date     : Fri, 14 Jun 2019 11:33:40 -0400    
  
committer: Alvaro Herrera <[email protected]>    
date     : Fri, 14 Jun 2019 11:33:40 -0400    

Click here for diff

Introduced in de87a084c0a5.  

M src/backend/access/heap/heapam.c

Attempt to identify system timezone by reading /etc/localtime symlink.

commit   : 75b0f21e1b197ba1e2f24a05b214dc1a2904db4f    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 14 Jun 2019 11:25:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 14 Jun 2019 11:25:13 -0400    

Click here for diff

On many modern platforms, /etc/localtime is a symlink to a file within the  
IANA database.  Reading the symlink lets us find out the name of the system  
timezone directly, without going through the brute-force search embodied in  
scan_available_timezones().  This shortens the runtime of initdb by some  
tens of ms, which is helpful for the buildfarm, and it also allows us to  
reliably select the same zone name the system was actually configured for,  
rather than possibly choosing one of IANA's many zone aliases.  (For  
example, in a system configured for "Asia/Tokyo", the brute-force search  
would not choose that name but its alias "Japan", on the grounds of the  
latter string being shorter.  More surprisingly, "Navajo" is preferred  
to either "America/Denver" or "US/Mountain", as seen in an old complaint  
from Josh Berkus.)  
  
If /etc/localtime doesn't exist, or isn't a symlink, or we can't make  
sense of its contents, or the contents match a zone we know but that  
zone doesn't match the observed behavior of localtime(), fall back to  
the brute-force search.  
  
Also, tweak initdb so that it prints the zone name it selected.  
  
In passing, replace the last few references to the "Olson" database in  
code comments with "IANA", as that's been our preferred term since  
commit b2cbced9e.  
  
Back-patch of commit 23bd3cec6.  The original intention was to not  
back-patch, since this can result in cosmetic behavioral changes ---  
for example, on my own workstation initdb now chooses "America/New_York",  
where it used to prefer "US/Eastern" which is equivalent and shorter.  
However, our hand has been more or less forced by tzdb update 2019a,  
which made the "UCT" zone fully equivalent to "UTC".  Our old code  
now prefers "UCT" on the grounds of it being alphabetically first,  
and that's making nobody happy.  Choosing the alias indicated by  
/etc/localtime is a more defensible behavior.  (Users who don't like  
the results can always force the decision by setting the TZ environment  
variable before running initdb.)  
  
Patch by me, per a suggestion from Robert Haas; review by Michael Paquier  
  
Discussion: https://postgr.es/m/[email protected]  
Discussion: https://postgr.es/m/[email protected]  

M src/bin/initdb/findtimezone.c
M src/bin/initdb/initdb.c
M src/interfaces/ecpg/pgtypeslib/dt_common.c

Avoid spurious deadlocks when upgrading a tuple lock

commit   : cb2398d8069ea5c93c005a48b7778338602b658b    
  
author   : Alvaro Herrera <[email protected]>    
date     : Thu, 13 Jun 2019 17:28:24 -0400    
  
committer: Alvaro Herrera <[email protected]>    
date     : Thu, 13 Jun 2019 17:28:24 -0400    

Click here for diff

When two (or more) transactions are waiting for transaction T1 to release a  
tuple-level lock, and transaction T1 upgrades its lock to a higher level, a  
spurious deadlock can be reported among the waiting transactions when T1  
finishes.  The simplest example case seems to be:  
  
T1: select id from job where name = 'a' for key share;  
Y: select id from job where name = 'a' for update; -- starts waiting for X  
Z: select id from job where name = 'a' for key share;  
T1: update job set name = 'b' where id = 1;  
Z: update job set name = 'c' where id = 1; -- starts waiting for X  
T1: rollback;  
  
At this point, transaction Y is rolled back on account of a deadlock: Y  
holds the heavyweight tuple lock and is waiting for the Xmax to be released,  
while Z holds part of the multixact and tries to acquire the heavyweight  
lock (per protocol) and goes to sleep; once X releases its part of the  
multixact, Z is awakened only to be put back to sleep on the heavyweight  
lock that Y is holding while sleeping.  Kaboom.  
  
This can be avoided by having Z skip the heavyweight lock acquisition.  As  
far as I can see, the biggest downside is that if there are multiple Z  
transactions, the order in which they resume after X finishes is not  
guaranteed.  
  
Backpatch to 9.6.  The patch applies cleanly on 9.5, but the new tests don't  
work there (because isolationtester is not smart enough), so I'm not going  
to risk it.  
  
Author: Oleksii Kliukin  
Discussion: https://postgr.es/m/[email protected]  

M src/backend/access/heap/README.tuplock
M src/backend/access/heap/heapam.c
A src/test/isolation/expected/tuplelock-upgrade-no-deadlock.out
M src/test/isolation/isolation_schedule
A src/test/isolation/specs/tuplelock-upgrade-no-deadlock.spec

Mark ReplicationSlotCtl as PGDLLIMPORT.

commit   : 9065fc2bd1cfd752ab57c6b8da38be423e4257bd    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 13 Jun 2019 10:53:17 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 13 Jun 2019 10:53:17 -0400    

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Also MyReplicationSlot, in branches where it wasn't already.  
  
This was discussed in the thread that resulted in c572599c6, but  
for some reason nobody pulled the trigger.  Now that we have another  
request for the same thing, we should just do it.  
  
Craig Ringer  
  
Discussion: https://postgr.es/m/CAMsr+YFTsq-86MnsNng=mPvjjh5EAbzfMK0ptJPvzyvpFARuRg@mail.gmail.com  
Discussion: https://postgr.es/m/[email protected]  

M src/include/replication/slot.h

postgres_fdw: Account for triggers in non-direct remote UPDATE planning.

commit   : 1ade21e7facc1202dadca4e916f4d5d3723f84b9    
  
author   : Etsuro Fujita <[email protected]>    
date     : Thu, 13 Jun 2019 17:59:13 +0900    
  
committer: Etsuro Fujita <[email protected]>    
date     : Thu, 13 Jun 2019 17:59:13 +0900    

Click here for diff

Previously, in postgresPlanForeignModify, we planned an UPDATE operation  
on a foreign table so that we transmit only columns that were explicitly  
targets of the UPDATE, so as to avoid unnecessary data transmission, but  
if there were BEFORE ROW UPDATE triggers on the foreign table, those  
triggers might change values for non-target columns, in which case we  
would miss sending changed values for those columns.  Prevent optimizing  
away transmitting all columns if there are BEFORE ROW UPDATE triggers on  
the foreign table.  
  
This is an oversight in commit 7cbe57c34 which added triggers on foreign  
tables, so apply the patch all the way back to 9.4 where that came in.  
  
Author: Shohei Mochizuki  
Reviewed-by: Amit Langote  
Discussion: https://postgr.es/m/[email protected]  

M contrib/postgres_fdw/expected/postgres_fdw.out
M contrib/postgres_fdw/postgres_fdw.c
M contrib/postgres_fdw/sql/postgres_fdw.sql

Doc: improve description of allowed spellings for Boolean input.

commit   : 457dab1e7bc694811974a24690846de00de6b4fb    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 12 Jun 2019 22:54:46 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 12 Jun 2019 22:54:46 -0400    

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datatype.sgml failed to explain that boolin() accepts any unique  
prefix of the basic input strings.  Indeed it was actively misleading  
because it called out a few minimal prefixes without mentioning that  
there were more valid inputs.  
  
I also felt that it wasn't doing anybody any favors by conflating  
SQL key words, valid Boolean input, and string literals containing  
valid Boolean input.  Rewrite in hopes of reducing the confusion.  
  
Per bug #15836 from Yuming Wang, as diagnosed by David Johnston.  
Back-patch to supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

M doc/src/sgml/datatype.sgml

Fix incorrect printing of queries with duplicated join names.

commit   : ad3e61b2809e5fc0133ca5bc6dde7450f85a00c1    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 12 Jun 2019 19:42:39 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 12 Jun 2019 19:42:39 -0400    

Click here for diff

Given a query in which multiple JOIN nodes used the same alias  
(which'd necessarily be in different sub-SELECTs), ruleutils.c  
would assign the JOIN nodes distinct aliases for clarity ...  
but then it forgot to print the modified aliases when dumping  
the JOIN nodes themselves.  This results in a dump/reload hazard  
for views, because the emitted query is flat-out incorrect:  
Vars will be printed with table names that have no referent.  
  
This has been wrong for a long time, so back-patch to all supported  
branches.  
  
Philip Dubé  
  
Discussion: https://postgr.es/m/CY4PR2101MB080246F2955FF58A6ED1FEAC98140@CY4PR2101MB0802.namprd21.prod.outlook.com  

M src/backend/utils/adt/ruleutils.c
M src/test/regress/expected/create_view.out
M src/test/regress/sql/create_view.sql

Fix ALTER COLUMN TYPE failure with a partial exclusion constraint.

commit   : 77d45b790e12c654962957ea43f430a59eff4e7e    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 12 Jun 2019 12:29:24 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 12 Jun 2019 12:29:24 -0400    

Click here for diff

ATExecAlterColumnType failed to consider the possibility that an index  
that needs to be rebuilt might be a child of a constraint that needs to be  
rebuilt.  We missed this so far because usually a constraint index doesn't  
have a direct dependency on its table, just on the constraint object.  
But if there's a WHERE clause, then dependency analysis of the WHERE  
clause results in direct dependencies on the column(s) mentioned in WHERE.  
This led to trying to drop and rebuild both the constraint and its  
underlying index.  
  
In v11/HEAD, we successfully drop both the index and the constraint,  
and then try to rebuild both, and of course the second rebuild hits a  
duplicate-index-name problem.  Before v11, it fails with obscure messages  
about a missing relation OID, due to trying to drop the index twice.  
  
This is essentially the same kind of problem noted in commit  
20bef2c31: the possible dependency linkages are broader than what  
ATExecAlterColumnType was designed for.  It was probably OK when  
written, but it's certainly been broken since the introduction of  
partial exclusion constraints.  Fix by adding an explicit check  
for whether any of the indexes-to-be-rebuilt belong to any of the  
constraints-to-be-rebuilt, and ignoring any that do.  
  
In passing, fix a latent bug introduced by commit 8b08f7d48: in  
get_constraint_index() we must "continue" not "break" when rejecting  
a relation of a wrong relkind.  This is harmless today because we don't  
expect that code path to be taken anyway; but if there ever were any  
relations to be ignored, the existing coding would have an extremely  
undesirable dependency on the order of pg_depend entries.  
  
Also adjust a couple of obsolete comments.  
  
Per bug #15835 from Yaroslav Schekin.  Back-patch to all supported  
branches.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/backend/catalog/pg_depend.c
M src/backend/commands/tablecmds.c
M src/test/regress/expected/alter_table.out
M src/test/regress/sql/alter_table.sql

Fix handling of COMMENT for domain constraints

commit   : ff1a25601e750e50a77fe09ceb6ed473f93d8e93    
  
author   : Michael Paquier <[email protected]>    
date     : Wed, 12 Jun 2019 11:31:14 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Wed, 12 Jun 2019 11:31:14 +0900    

Click here for diff

For a non-superuser, changing a comment on a domain constraint was  
leading to a cache lookup failure as the code tried to perform the  
ownership lookup on the constraint OID itself, thinking that it was a  
type, but this check needs to happen on the type the domain constraint  
relies on.  As the type a domain constraint relies on can be guessed  
directly based on the constraint OID, first fetch its type OID and  
perform the ownership on it.  
  
This is broken since 7eca575, which has split the handling of comments  
for table constraints and domain constraints, so back-patch down to  
9.5.  
  
Reported-by: Clemens Ladisch  
Author: Daniel Gustafsson, Michael Paquier  
Reviewed-by: Álvaro Herrera  
Discussion: https://postgr.es/m/[email protected]  
Backpatch-through: 9.5  

M src/backend/catalog/objectaddress.c
M src/test/regress/input/constraints.source
M src/test/regress/output/constraints.source

Don't access catalogs to validate GUCs when not connected to a DB.

commit   : b8607e15e0fa0a3ac20779e39eea24fd67ebb650    
  
author   : Andres Freund <[email protected]>    
date     : Mon, 10 Jun 2019 23:20:48 -0700    
  
committer: Andres Freund <[email protected]>    
date     : Mon, 10 Jun 2019 23:20:48 -0700    

Click here for diff

Vignesh found this bug in the check function for  
default_table_access_method's check hook, but that was just copied  
from older GUCs. Investigation by Michael and me then found the bug in  
further places.  
  
When not connected to a database (e.g. in a walsender connection), we  
cannot perform (most) GUC checks that need database access. Even when  
only shared tables are needed, unless they're  
nailed (c.f. RelationCacheInitializePhase2()), they cannot be accessed  
without pg_class etc. being present.  
  
Fix by extending the existing IsTransactionState() checks to also  
check for MyDatabaseOid.  
  
Reported-By: Vignesh C, Michael Paquier, Andres Freund  
Author: Vignesh C, Andres Freund  
Discussion: https://postgr.es/m/CALDaNm1KXK9gbZfY-p_peRFm_XrBh1OwQO1Kk6Gig0c0fVZ2uw%40mail.gmail.com  
Backpatch: 9.4-  

M src/backend/commands/tablespace.c
M src/backend/utils/cache/ts_cache.c

Fix operator naming in pg_trgm GUC option descriptions

commit   : 959792087a10baf7f1b58408d28411109bcedb7a    
  
author   : Alexander Korotkov <[email protected]>    
date     : Mon, 10 Jun 2019 20:14:19 +0300    
  
committer: Alexander Korotkov <[email protected]>    
date     : Mon, 10 Jun 2019 20:14:19 +0300    

Click here for diff

Descriptions of pg_trgm GUC options have % replaced with %% like it was  
a printf-like format.  But that's not needed since they are just plain strings.  
This commit fixed that.  Backpatch to last supported version since this error  
present from the beginning.  
  
Reported-by: Masahiko Sawada  
Discussion: https://postgr.es/m/CAD21AoAgPKODUsu9gqUFiNqEOAqedStxJ-a0sapsJXWWAVp%3Dxg%40mail.gmail.com  
Backpatch-through: 9.4  

M contrib/pg_trgm/trgm_op.c

Add docs of missing GUC to pgtrgm.sgml

commit   : 97c9ea17fbcaaf89033002189f6b0aba6ad3179d    
  
author   : Alexander Korotkov <[email protected]>    
date     : Mon, 10 Jun 2019 19:38:13 +0300    
  
committer: Alexander Korotkov <[email protected]>    
date     : Mon, 10 Jun 2019 19:38:13 +0300    

Click here for diff

be8a7a68 introduced pg_trgm.strict_word_similarity_threshold GUC, but missed  
docs for that.  This commit fixes that.  
  
Discussion: https://postgr.es/m/fc907f70-448e-fda3-3aa4-209a59597af0%402ndquadrant.com  
Author: Ian Barwick  
Reviewed-by: Masahiko Sawada, Michael Paquier  
Backpatch-through: 9.6  

M doc/src/sgml/pgtrgm.sgml

Fix docs indentation in pgtrgm.sgml

commit   : abfbdb25ec2ac65390403bf118916d4568d0e73a    
  
author   : Alexander Korotkov <[email protected]>    
date     : Mon, 10 Jun 2019 19:28:47 +0300    
  
committer: Alexander Korotkov <[email protected]>    
date     : Mon, 10 Jun 2019 19:28:47 +0300    

Click here for diff

5871b884 introduced pg_trgm.word_similarity_threshold GUC, but its documentation  
contains wrong indentation.  This commit fixes that.  Backpatch for easier  
backpatching of other documentation fixes.  
  
Discussion: https://postgr.es/m/4c735d30-ab59-fc0e-45d8-f90eb5ed3855%402ndquadrant.com  
Author: Ian Barwick  
Backpatch-through: 9.6  

M doc/src/sgml/pgtrgm.sgml

Fix copy-pasto in freeing memory on error in vacuumlo.

commit   : 2558776b415097610ab69a03604e79d6958608bc    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Fri, 7 Jun 2019 12:44:04 +0300    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Fri, 7 Jun 2019 12:44:04 +0300    

Click here for diff

It's harmless to call PQfreemem() with a NULL argument, so the only  
consequence was that if allocating 'schema' failed, but allocating 'table'  
or 'field' succeeded, we would leak a bit of memory. That's highly  
unlikely to happen, so this is just academical, but let's get it right.  
  
Per bug #15838 from Timur Birsh. Backpatch back to 9.5, where the  
PQfreemem() calls were introduced.  
  
Discussion: https://www.postgresql.org/message-id/[email protected]  

M contrib/vacuumlo/vacuumlo.c

Fix inconsistency in comments atop ExecParallelEstimate.

commit   : 5afb57038f338adefb282afb7976c3ab86a92085    
  
author   : Amit Kapila <[email protected]>    
date     : Fri, 7 Jun 2019 05:45:06 +0530    
  
committer: Amit Kapila <[email protected]>    
date     : Fri, 7 Jun 2019 05:45:06 +0530    

Click here for diff

When this code was initially introduced in commit d1b7c1ff, the structure  
used was SharedPlanStateInstrumentation, but later when it got changed to  
Instrumentation structure in commit b287df70, we forgot to update the  
comment.  
  
Reported-by: Wu Fei  
Author: Wu Fei  
Reviewed-by: Amit Kapila  
Backpatch-through: 9.6  
Discussion: https://postgr.es/m/52E6E0843B9D774C8C73D6CF64402F0562215EB2@G08CNEXMBPEKD02.g08.fujitsu.local  

M src/backend/executor/execParallel.c

commit   : f46eae4fc140ae7e86825095ea7e029cbecddfc7    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 3 Jun 2019 21:25:43 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 3 Jun 2019 21:25:43 -0400    

Click here for diff

Back-patch commit 09a65f5a2 into the 9.6 and 10 branches.  
Needed to support back-patch of commit 2cd4e8357 on Windows.  
  
Discussion: http://postgr.es/m/[email protected]  

M src/include/access/parallel.h

Fix contrib/auto_explain to not cause problems in parallel workers.

commit   : efa121ae6a86f493cd40d0e22dfce5e75ec1f94b    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 3 Jun 2019 18:06:04 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 3 Jun 2019 18:06:04 -0400    

Click here for diff

A parallel worker process should not be making any decisions of its  
own about whether to auto-explain.  If the parent session process  
passed down flags asking for instrumentation data, do that, otherwise  
not.  Trying to enable instrumentation anyway leads to bugs like the  
"could not find key N in shm TOC" failure reported in bug #15821  
from Christian Hofstaedtler.  
  
We can implement this cheaply by piggybacking on the existing logic  
for not doing anything when we've chosen not to sample a statement.  
  
While at it, clean up some tin-eared coding related to the sampling  
feature, including an off-by-one error that meant that asking for 1.0  
sampling rate didn't actually result in sampling every statement.  
  
Although the specific case reported here only manifested in >= v11,  
I believe that related misbehaviors can be demonstrated in any version  
that has parallel query; and the off-by-one error is certainly there  
back to 9.6 where that feature was added.  So back-patch to 9.6.  
  
Discussion: https://postgr.es/m/[email protected]  

M contrib/auto_explain/auto_explain.c

Fix documentation of check_option in information_schema.views

commit   : a4291d07fcf20f0ba61031d23d02916723a5e23f    
  
author   : Michael Paquier <[email protected]>    
date     : Sat, 1 Jun 2019 15:34:08 -0400    
  
committer: Michael Paquier <[email protected]>    
date     : Sat, 1 Jun 2019 15:34:08 -0400    

Click here for diff

Support of CHECK OPTION for updatable views has been added in 9.4, but  
the documentation of information_schema never got the call even if the  
information displayed is correct.  
  
Author: Gilles Darold  
Discussion: https://postgr.es/m/[email protected]  
Backpatch-through: 9.4  

M doc/src/sgml/information_schema.sgml

Fix C++ incompatibilities in plpgsql's header files.

commit   : c332c94adb70a21f2389d1e6f4072ff33186d7c0    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 31 May 2019 12:34:55 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 31 May 2019 12:34:55 -0400    

Click here for diff

Rename some exposed parameters so that they don't conflict with  
C++ reserved words.  
  
Back-patch to all supported versions.  
  
George Tarasov  
  
Discussion: https://postgr.es/m/[email protected]  

M src/pl/plpgsql/src/plpgsql.h

MSVC: Add "use File::Path qw(rmtree)".

commit   : 7a518cba67a6572a83394e7e711ce3ded22489c3    
  
author   : Noah Misch <[email protected]>    
date     : Tue, 28 May 2019 19:28:36 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Tue, 28 May 2019 19:28:36 -0700    

Click here for diff

My back-patch of commit 10b72deafea5972edcafb9eb3f97154f32ccd340 added  
calls to File::Path::rmtree(), but v10 and older had not been importing  
that symbol.  Back-patch to v10, 9.6 and 9.5.  

M src/tools/msvc/vcregress.pl

In the pg_upgrade test suite, don't write to src/test/regress.

commit   : 5e89aa021e00a5a3c3b0475eaa232a1e62cb1061    
  
author   : Noah Misch <[email protected]>    
date     : Tue, 28 May 2019 12:59:00 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Tue, 28 May 2019 12:59:00 -0700    

Click here for diff

When this suite runs installcheck, redirect file creations from  
src/test/regress to src/bin/pg_upgrade/tmp_check/regress.  This closes a  
race condition in "make -j check-world".  If the pg_upgrade suite wrote  
to a given src/test/regress/results file in parallel with the regular  
src/test/regress invocation writing it, a test failed spuriously.  Even  
without parallelism, in "make -k check-world", the suite finishing  
second overwrote the other's regression.diffs.  This revealed test  
"largeobject" assuming @abs_builddir@ is getcwd(), so fix that, too.  
  
Buildfarm client REL_10, released fifty-four days ago, supports saving  
regression.diffs from its new location.  When an older client reports a  
pg_upgradeCheck failure, it will no longer include regression.diffs.  
Back-patch to 9.5, where pg_upgrade moved to src/bin.  
  
Reviewed (in earlier versions) by Andrew Dunstan.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/bin/pg_upgrade/test.sh
M src/test/regress/input/largeobject.source
M src/test/regress/output/largeobject.source
M src/test/regress/output/largeobject_1.source
M src/tools/msvc/vcregress.pl

In the pg_upgrade test suite, remove and recreate "tmp_check".

commit   : 63f82b384e67240497468cdd7ff521557b30dd55    
  
author   : Noah Misch <[email protected]>    
date     : Tue, 28 May 2019 12:58:30 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Tue, 28 May 2019 12:58:30 -0700    

Click here for diff

This allows "vcregress upgradecheck" to pass twice in immediate  
succession, and it's more like how $(prove_check) works.  Back-patch to  
9.5, where pg_upgrade moved to src/bin.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/bin/pg_upgrade/test.sh
M src/tools/msvc/vcregress.pl

pg_upgrade: Make test.sh's installcheck use to-be-upgraded version's bindir.

commit   : 5518293475f853f0ecd6eaf8c02e454314e9c81e    
  
author   : Andres Freund <[email protected]>    
date     : Thu, 23 May 2019 14:46:57 -0700    
  
committer: Andres Freund <[email protected]>    
date     : Thu, 23 May 2019 14:46:57 -0700    

Click here for diff

On master (after 700538) the old version's installed psql was used -  
even when the old version might not actually be installed / might be  
installed into a temporary directory. As commonly the case when just  
executing make check for pg_upgrade, as $oldbindir is just the current  
version's $bindir.  
  
In the back branches, with --install specified, psql from the new  
version's temporary installation was used, without --install (e.g for  
NO_TEMP_INSTALL, cf 47b3c26642), the new version's installed psql was  
used (which might or might not exist).  
  
Author: Andres Freund  
Discussion: https://postgr.es/m/[email protected]  

M src/bin/pg_upgrade/test.sh

Fix ordering of GRANT commands in pg_dumpall for tablespaces

commit   : c82e8ba0016319bb7c18ace7a9a77a7d7550f997    
  
author   : Michael Paquier <[email protected]>    
date     : Thu, 23 May 2019 10:48:35 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Thu, 23 May 2019 10:48:35 +0900    

Click here for diff

This uses a method similar to 68a7c24f and now b8c6014 (applied for  
database creation), which guarantees that GRANT commands using the WITH  
GRANT OPTION are dumped in a way so as cascading dependencies are  
respected.  Note that tablespaces do not have support for initial  
privileges via pg_init_privs, so the same method needs to be applied  
again.  It would be nice to merge all the logic generating ACL queries  
in dumps under the same banner, but this requires extending the support  
of pg_init_privs to objects that cannot use it yet, so this is left as  
future work.  
  
Discussion: https://postgr.es/m/[email protected]  
Author: Michael Paquier  
Reviewed-by: Nathan Bossart  
Backpatch-through: 9.6  

M src/bin/pg_dump/pg_dumpall.c

Fix ordering of GRANT commands in pg_dumpall for database creation

commit   : a21fb12e7cc3e5ef976a384e7e7295d7e9b7460d    
  
author   : Michael Paquier <[email protected]>    
date     : Wed, 22 May 2019 14:48:39 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Wed, 22 May 2019 14:48:39 +0900    

Click here for diff

This uses a method similar to 68a7c24f, which guarantees that GRANT  
commands using the WITH GRANT OPTION are dumped in a way so as cascading  
dependencies are respected.  As databases do not have support for  
initial privileges via pg_init_privs, we need to repeat again the same  
ACL reordering method.  
  
ACL for databases have been moved from pg_dumpall to pg_dump in v11, so  
this impacts pg_dump for v11 and above, and pg_dumpall for v9.6 and  
v10.  
  
Discussion: https://postgr.es/m/[email protected]  
Author: Nathan Bossart  
Reviewed-by: Haribabu Kommi  
Backpatch-through: 9.6  

M src/bin/pg_dump/pg_dumpall.c

Fix some grammar in documentation of spgist and pgbench

commit   : be56bf76b0f397e6479407d8d522a50eae8e29d5    
  
author   : Michael Paquier <[email protected]>    
date     : Mon, 20 May 2019 09:48:44 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Mon, 20 May 2019 09:48:44 +0900    

Click here for diff

Discussion: https://postgr.es/m/[email protected]  
Author: Liudmila Mantrova  
Reviewed-by: Jonathan Katz, Tom Lane, Michael Paquier  
Backpatch-through: 9.4  

M doc/src/sgml/ref/pgbench.sgml
M doc/src/sgml/spgist.sgml

Revert "In the pg_upgrade test suite, don't write to src/test/regress."

commit   : 4796c5ec4790bca5bd2d1f54c35be81d4421918b    
  
author   : Noah Misch <[email protected]>    
date     : Sun, 19 May 2019 15:24:42 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Sun, 19 May 2019 15:24:42 -0700    

Click here for diff

This reverts commit bd1592e8570282b1650af6b8eede0016496daecd.  It had  
multiple defects.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/bin/pg_upgrade/test.sh
M src/test/regress/input/largeobject.source
M src/test/regress/output/largeobject.source
M src/test/regress/output/largeobject_1.source
M src/tools/msvc/vcregress.pl

In the pg_upgrade test suite, don't write to src/test/regress.

commit   : 4f4b2d4161b1406f6f37c164cf2f383d2ec7a684    
  
author   : Noah Misch <[email protected]>    
date     : Sun, 19 May 2019 14:36:44 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Sun, 19 May 2019 14:36:44 -0700    

Click here for diff

When this suite runs installcheck, redirect file creations from  
src/test/regress to src/bin/pg_upgrade/tmp_check/regress.  This closes a  
race condition in "make -j check-world".  If the pg_upgrade suite wrote  
to a given src/test/regress/results file in parallel with the regular  
src/test/regress invocation writing it, a test failed spuriously.  Even  
without parallelism, in "make -k check-world", the suite finishing  
second overwrote the other's regression.diffs.  This revealed test  
"largeobject" assuming @abs_builddir@ is getcwd(), so fix that, too.  
  
Buildfarm client REL_10, released forty-five days ago, supports saving  
regression.diffs from its new location.  When an older client reports a  
pg_upgradeCheck failure, it will no longer include regression.diffs.  
Back-patch to 9.5, where pg_upgrade moved to src/bin.  
  
Reviewed by Andrew Dunstan.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/bin/pg_upgrade/test.sh
M src/test/regress/input/largeobject.source
M src/test/regress/output/largeobject.source
M src/test/regress/output/largeobject_1.source
M src/tools/msvc/vcregress.pl

Add isolation test for INSERT ON CONFLICT speculative insertion failure.

commit   : 0491a51fdd4e87fd5ab42ae42dfb9931cac681f6    
  
author   : Andres Freund <[email protected]>    
date     : Tue, 14 May 2019 11:45:40 -0700    
  
committer: Andres Freund <[email protected]>    
date     : Tue, 14 May 2019 11:45:40 -0700    

Click here for diff

This path previously was not reliably covered. There was some  
heuristic coverage via insert-conflict-toast.spec, but that test is  
not deterministic, and only tested for a somewhat specific bug.  
  
Backpatch, as this is a complicated and otherwise untested code  
path. Unfortunately 9.5 cannot handle two waiting sessions, and thus  
cannot execute this test.  
  
Triggered by a conversion with Melanie Plageman.  
  
Author: Andres Freund  
Discussion: https://postgr.es/m/CAAKRu_a7hbyrk=wveHYhr4LbcRnRCG=yPUVoQYB9YO1CdUBE9Q@mail.gmail.com  
Backpatch: 9.5-  

A src/test/isolation/expected/insert-conflict-specconflict.out
M src/test/isolation/isolation_schedule
A src/test/isolation/specs/insert-conflict-specconflict.spec

Doc: Refer to line pointers as item identifiers.

commit   : 80873a6ec590cdbe10ca0cd987b8ca3dcf5ef764    
  
author   : Peter Geoghegan <[email protected]>    
date     : Mon, 13 May 2019 15:39:01 -0700    
  
committer: Peter Geoghegan <[email protected]>    
date     : Mon, 13 May 2019 15:39:01 -0700    

Click here for diff

An upcoming HEAD-only patch will standardize the terminology around  
ItemIdData variables/line pointers, ending the practice of referring to  
them as "item pointers".  Make the "Database Page Layout" docs  
consistent with the new policy.  The term "item identifier" is already  
used in the same section, so stick with that.  
  
Discussion: https://postgr.es/m/CAH2-Wz=c=MZQjUzde3o9+2PLAPuHTpVZPPdYxN=E4ndQ2--8ew@mail.gmail.com  
Backpatch: All supported branches.  

M doc/src/sgml/storage.sgml

Fix misuse of an integer as a bool.

commit   : 8eaba0b93da10659f8796d6e740f656476d4925f    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 13 May 2019 10:53:19 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 13 May 2019 10:53:19 -0400    

Click here for diff

pgtls_read_pending is declared to return bool, but what the underlying  
SSL_pending function returns is a count of available bytes.  
  
This is actually somewhat harmless if we're using C99 bools, but in  
the back branches it's a live bug: if the available-bytes count happened  
to be a multiple of 256, it would get converted to a zero char value.  
On machines where char is signed, counts of 128 and up could misbehave  
as well.  The net effect is that when using SSL, libpq might block  
waiting for data even though some has already been received.  
  
Broken by careless refactoring in commit 4e86f1b16, so back-patch  
to 9.5 where that came in.  
  
Per bug #15802 from David Binderman.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/interfaces/libpq/fe-misc.c
M src/interfaces/libpq/fe-secure-openssl.c

postgres_fdw: Fix typo in comment.

commit   : af16f0a7045da816d33d8b23045eca5c2473342c    
  
author   : Etsuro Fujita <[email protected]>    
date     : Mon, 13 May 2019 17:30:40 +0900    
  
committer: Etsuro Fujita <[email protected]>    
date     : Mon, 13 May 2019 17:30:40 +0900    

Click here for diff

M contrib/postgres_fdw/postgres_fdw.c

Fix misoptimization of "{1,1}" quantifiers in regular expressions.

commit   : 2a3dbc151b712a18ef02c03c8bb31b6608c7b56d    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 12 May 2019 18:53:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 12 May 2019 18:53:13 -0400    

Click here for diff

A bounded quantifier with m = n = 1 might be thought a no-op.  But  
according to our documentation (which traces back to Henry Spencer's  
original man page) it still imposes greediness, or non-greediness in the  
case of the non-greedy variant "{1,1}?", on whatever it's attached to.  
  
This turns out not to work though, because parseqatom() optimizes away  
the m = n = 1 case without regard for whether it's supposed to change  
the greediness of the argument RE.  
  
We can fix this by just not applying the optimization when the greediness  
needs to change; the subsequent general cases handle it fine.  
  
The three cases in which we can still apply the optimization are  
(a) no quantifier, or quantifier does not impose a preference;  
(b) atom has no greediness property, implying it cannot match a  
variable amount of text anyway; or  
(c) quantifier's greediness is same as atom's.  
Note that in most cases where one of these applies, we'd have exited  
earlier in the "not a messy case" fast path.  I think it's now only  
possible to get to the optimization when the atom involves capturing  
parentheses or a non-top-level backref.  
  
Back-patch to all supported branches.  I'd ordinarily be hesitant to  
put a subtle behavioral change into back branches, but in this case  
it's very hard to see a reason why somebody would write "{1,1}?" unless  
they're trying to get the documented change-of-greediness behavior.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/backend/regex/regcomp.c
M src/test/regress/expected/regex.out
M src/test/regress/sql/regex.sql

Fail pgwin32_message_to_UTF16() for SQL_ASCII messages.

commit   : ff7555c4f13aa0c62f8e1ad890b2a2c0f512b4fc    
  
author   : Noah Misch <[email protected]>    
date     : Sun, 12 May 2019 10:33:05 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Sun, 12 May 2019 10:33:05 -0700    

Click here for diff

The function had been interpreting SQL_ASCII messages as UTF8, throwing  
an error when they were invalid UTF8.  The new behavior is consistent  
with pg_do_encoding_conversion().  This affects LOG_DESTINATION_STDERR  
and LOG_DESTINATION_EVENTLOG, which will send untranslated bytes to  
write() and ReportEventA().  On buildfarm member bowerbird, enabling  
log_connections caused an error whenever the role name was not valid  
UTF8.  Back-patch to 9.4 (all supported versions).  
  
Discussion: https://postgr.es/m/[email protected]  

M src/backend/utils/mb/mbutils.c

Rearrange pgstat_bestart() to avoid failures within its critical section.

commit   : 27d3394b0d8979e632d562927f1438f1befcb84a    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 11 May 2019 21:27:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 11 May 2019 21:27:13 -0400    

Click here for diff

We long ago decided to design the shared PgBackendStatus data structure to  
minimize the cost of writing status updates, which means that writers just  
have to increment the st_changecount field twice.  That isn't hooked into  
any sort of resource management mechanism, which means that if something  
were to throw error between the two increments, the st_changecount field  
would be left odd indefinitely.  That would cause readers to lock up.  
Now, since it's also a bad idea to leave the field odd for longer than  
absolutely necessary (because readers will spin while we have it set),  
the expectation was that we'd treat these segments like spinlock critical  
sections, with only short, more or less straight-line, code in them.  
  
That was fine as originally designed, but commit 9029f4b37 broke it  
by inserting a significant amount of non-straight-line code into  
pgstat_bestart(), code that is very capable of throwing errors, not to  
mention taking a significant amount of time during which readers will spin.  
We have a report from Neeraj Kumar of readers actually locking up, which  
I suspect was due to an encoding conversion error in X509_NAME_to_cstring,  
though conceivably it was just a garden-variety OOM failure.  
  
Subsequent commits have loaded even more dubious code into pgstat_bestart's  
critical section (and commit fc70a4b0d deserves some kind of booby prize  
for managing to miss the critical section entirely, although the negative  
consequences seem minimal given that the PgBackendStatus entry should be  
seen by readers as inactive at that point).  
  
The right way to fix this mess seems to be to compute all these values  
into a local copy of the process' PgBackendStatus struct, and then just  
copy the data back within the critical section proper.  This plan can't  
be implemented completely cleanly because of the struct's heavy reliance  
on out-of-line strings, which we must initialize separately within the  
critical section.  But still, the critical section is far smaller and  
safer than it was before.  
  
In hopes of forestalling future errors of the same ilk, rename the  
macros for st_changecount management to make it more apparent that  
the writer-side macros create a critical section.  And to prevent  
the worst consequences if we nonetheless manage to mess it up anyway,  
adjust those macros so that they really are a critical section, ie  
they now bump CritSectionCount.  That doesn't add much overhead, and  
it guarantees that if we do somehow throw an error while the counter  
is odd, it will lead to PANIC and a database restart to reset shared  
memory.  
  
Back-patch to 9.5 where the problem was introduced.  
  
In HEAD, also fix an oversight in commit b0b39f72b: it failed to teach  
pgstat_read_current_status to copy st_gssstatus data from shared memory to  
local memory.  Hence, subsequent use of that data within the transaction  
would potentially see changing data that it shouldn't see.  
  
Discussion: https://postgr.es/m/CAPR3Wj5Z17=+eeyrn_ZDG3NQGYgMEOY6JV6Y-WRRhGgwc16U3Q@mail.gmail.com  

M src/backend/postmaster/pgstat.c
M src/include/pgstat.h

Honor TEMP_CONFIG in TAP suites.

commit   : 8dab099bb49c9f8784842c246f04c0e0a0f7c8f9    
  
author   : Noah Misch <[email protected]>    
date     : Sat, 11 May 2019 00:22:38 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Sat, 11 May 2019 00:22:38 -0700    

Click here for diff

The buildfarm client uses TEMP_CONFIG to implement its extra_config  
setting.  Except for stats_temp_directory, extra_config now applies to  
TAP suites; extra_config values seen in the past month are compatible  
with this.  Back-patch to 9.6, where PostgresNode was introduced, so the  
buildfarm can rely on it sooner.  
  
Reviewed by Andrew Dunstan and Tom Lane.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/bin/pg_ctl/t/001_start_stop.pl
M src/test/perl/PostgresNode.pm

Fix error reporting in reindexdb

commit   : 0c132d4581c2fc55a96445630eed82458d80d817    
  
author   : Michael Paquier <[email protected]>    
date     : Sat, 11 May 2019 13:01:19 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Sat, 11 May 2019 13:01:19 +0900    

Click here for diff

When failing to reindex a table or an index, reindexdb would generate an  
extra error message related to a database failure, which is misleading.  
  
Backpatch all the way down, as this has been introduced by 85e9a5a0.  
  
Discussion: https://postgr.es/m/CAOBaU_Yo61RwNO3cW6WVYWwH7EYMPuexhKqufb2nFGOdunbcHw@mail.gmail.com  
Author: Julien Rouhaud  
Reviewed-by: Daniel Gustafsson, Álvaro Herrera, Tom Lane, Michael  
Paquier  
Backpatch-through: 9.4  

M src/bin/scripts/reindexdb.c

Cope with EINVAL and EIDRM shmat() failures in PGSharedMemoryAttach.

commit   : a73c8caea46c703fcd90e17e28b6a9223ea24bd0    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 10 May 2019 14:56:41 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 10 May 2019 14:56:41 -0400    

Click here for diff

There's a very old race condition in our code to see whether a pre-existing  
shared memory segment is still in use by a conflicting postmaster: it's  
possible for the other postmaster to remove the segment in between our  
shmctl() and shmat() calls.  It's a narrow window, and there's no risk  
unless both postmasters are using the same port number, but that's possible  
during parallelized "make check" tests.  (Note that while the TAP tests  
take some pains to choose a randomized port number, pg_regress doesn't.)  
If it does happen, we treated that as an unexpected case and errored out.  
  
To fix, allow EINVAL to be treated as segment-not-present, and the same  
for EIDRM on Linux.  AFAICS, the considerations here are basically  
identical to the checks for acceptable shmctl() failures, so I documented  
and coded it that way.  
  
While at it, adjust PGSharedMemoryAttach's API to remove its undocumented  
dependency on UsedShmemSegAddr in favor of passing the attach address  
explicitly.  This makes it easier to be sure we're using a null shmaddr  
when probing for segment conflicts (thus avoiding questions about what  
EINVAL means).  I don't think there was a bug there, but it required  
fragile assumptions about the state of UsedShmemSegAddr during  
PGSharedMemoryIsInUse.  
  
Commit c09850992 may have made this failure more probable by applying  
the conflicting-segment tests more often.  Hence, back-patch to all  
supported branches, as that was.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/backend/port/sysv_shmem.c

Repair issues with faulty generation of merge-append plans.

commit   : 3203714c3f27af2c9a6335c640c34f24b34f4a62    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 9 May 2019 16:52:49 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 9 May 2019 16:52:49 -0400    

Click here for diff

create_merge_append_plan failed to honor the CP_EXACT_TLIST flag:  
it would generate the expected targetlist but then it felt free to  
add resjunk sort targets to it.  This demonstrably leads to assertion  
failures in v11 and HEAD, and it's probably just accidental that we  
don't see the same in older branches.  I've not looked into whether  
there would be any real-world consequences in non-assert builds.  
In HEAD, create_append_plan has sprouted the same problem, so fix  
that too (although we do not have any test cases that seem able to  
reach that bug).  This is an oversight in commit 3fc6e2d7f which  
invented the CP_EXACT_TLIST flag, so back-patch to 9.6 where that  
came in.  
  
convert_subquery_pathkeys would create pathkeys for subquery output  
values if they match any EquivalenceClass known in the outer query  
and are available in the subquery's syntactic targetlist.  However,  
the second part of that condition is wrong, because such values might  
not appear in the subquery relation's reltarget list, which would  
mean that they couldn't be accessed above the level of the subquery  
scan.  We must check that they appear in the reltarget list, instead.  
This can lead to dropping knowledge about the subquery's sort  
ordering, but I believe it's okay, because any sort key that the  
outer query actually has any interest in would appear in the  
reltarget list.  
  
This second issue is of very long standing, but right now there's no  
evidence that it causes observable problems before 9.6, so I refrained  
from back-patching further than that.  We can revisit that choice if  
somebody finds a way to make it cause problems in older branches.  
(Developing useful test cases for these issues is really problematic;  
fixing convert_subquery_pathkeys removes the only known way to exhibit  
the create_merge_append_plan bug, and neither of the test cases added  
by this patch causes a problem in all branches, even when considering  
the issues separately.)  
  
The second issue explains bug #15795 from Suresh Kumar R ("could not  
find pathkey item to sort" with nested DISTINCT queries).  I stumbled  
across the first issue while investigating that.  
  
Discussion: https://postgr.es/m/[email protected]  

M src/backend/optimizer/path/pathkeys.c
M src/backend/optimizer/plan/createplan.c
M src/test/regress/expected/union.out
M src/test/regress/sql/union.sql

Fix error status of vacuumdb when multiple jobs are used

commit   : a9a886c6fd9b446866af8d95bc997f6e88496aaa    
  
author   : Michael Paquier <[email protected]>    
date     : Thu, 9 May 2019 10:29:52 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Thu, 9 May 2019 10:29:52 +0900    

Click here for diff

When running a batch of VACUUM or ANALYZE commands on a given database,  
there were cases where it is possible to have vacuumdb not report an  
error where it actually should, leading to incorrect status results.  
  
Author: Julien Rouhaud  
Reviewed-by: Amit Kapila, Michael Paquier  
Discussion: https://postgr.es/m/CAOBaU_ZuTwz7CtqLYJ1Ouuh272bTQPLN8b1bAPk0bCBm4PDMTQ@mail.gmail.com  
Backpatch-through: 9.5  

M src/bin/scripts/vacuumdb.c

Fix documentation for the privileges required for replication functions.

commit   : 44b973b71c9566b946bd2a3dd1570d4fed1547a8    
  
author   : Fujii Masao <[email protected]>    
date     : Thu, 9 May 2019 01:35:13 +0900    
  
committer: Fujii Masao <[email protected]>    
date     : Thu, 9 May 2019 01:35:13 +0900    

Click here for diff

Previously it's documented that use of replication functions is  
restricted to superusers. This is true for the functions which  
use replication origin, but not for pg_logicl_emit_message() and  
functions which use replication slot. For example, not only  
superusers but also users with REPLICATION privilege is allowed  
to use the functions for replication slot. This commit fixes  
the documentation for the privileges required for those replication  
functions.  
  
Back-patch to 9.4 (all supported versions).  
  
Author: Matsumura Ryo  
Discussion: https://postgr.es/m/03040DFF97E6E54E88D3BFEE5F5480F74ABA6E16@G01JPEXMBYT04  

M doc/src/sgml/func.sgml

Probe only 127.0.0.1 when looking for ports on Unix.

commit   : 1ed42e50e9636f5c9c86c679afee9200ca4e2323    
  
author   : Thomas Munro <[email protected]>    
date     : Mon, 6 May 2019 15:02:41 +1200    
  
committer: Thomas Munro <[email protected]>    
date     : Mon, 6 May 2019 15:02:41 +1200    

Click here for diff

Commit c0985099, later adjusted by commit 4ab02e81, probed 0.0.0.0  
in addition to 127.0.0.1, for the benefit of Windows build farm  
animals.  It isn't really useful on Unix systems, and turned out to  
be a bit inconvenient to users of some corporate firewall software.  
Switch back to probing just 127.0.0.1 on non-Windows systems.  
  
Back-patch to 9.6, like the earlier changes.  
  
Discussion: https://postgr.es/m/CA%2BhUKG%2B21EPwfgs4m%2BtqyRtbVqkOUvP8QQ8sWk9%2Bh55Aub1H3A%40mail.gmail.com  

M src/test/perl/PostgresNode.pm

Remove leftover reference to old "flat file" mechanism in a comment.

commit   : b0c546136776f198c1858521698c074226eaed57    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Wed, 8 May 2019 09:32:34 +0300    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Wed, 8 May 2019 09:32:34 +0300    

Click here for diff

The flat file mechanism was removed in PostgreSQL 9.0.  

M src/backend/access/transam/xact.c

commit   : b806618ccf8cd8ad1c0e37167603f77eed2bc537    
  
author   : Michael Paquier <[email protected]>    
date     : Tue, 7 May 2019 14:20:08 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Tue, 7 May 2019 14:20:08 +0900    

Click here for diff

This code was broken as of 582edc3, and is most likely not used anymore.  
Note that pg_dump supports servers down to 8.0, and psql has code to  
support servers down to 7.4.  
  
Author: Julien Rouhaud  
Reviewed-by: Tom Lane  
Discussion: https://postgr.es/m/CAOBaU_Y5y=zo3+2gf+2NJC1pvMYPcbRXoQaPXx=U7+C8Qh4CzQ@mail.gmail.com  

M src/bin/scripts/common.c