PostgreSQL 9.6.20 commit log

commit   : e4554425e6d3b429a207ac1a109af9d7e1d14da6    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 9 Nov 2020 17:32:22 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 9 Nov 2020 17:32:22 -0500    

commit   : 0425151233e018edfc03d2c3fe38f94ef3a67e77    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 9 Nov 2020 13:02:14 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 9 Nov 2020 13:02:14 -0500    

Security: CVE-2020-25694, CVE-2020-25695, CVE-2020-25696  

commit   : d4fb509d07c36e1839ba2a1c0d00ff18606937f6    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 9 Nov 2020 12:02:24 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 9 Nov 2020 12:02:24 -0500    

After studying the code, NULLIF is a lot more subtle than you might  
have guessed.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 12fd81cb7fab49ba0a5f004596e52271275deec0    
  
author   : Noah Misch <[email protected]>    
date     : Mon, 9 Nov 2020 07:32:09 -0800    
  
committer: Noah Misch <[email protected]>    
date     : Mon, 9 Nov 2020 07:32:09 -0800    

If an interactive psql session used \gset when querying a compromised  
server, the attacker could execute arbitrary code as the operating  
system account running psql.  Using a prefix not found among specially  
treated variables, e.g. every lowercase string, precluded the attack.  
Fix by issuing a warning and setting no variable for the column in  
question.  Users wanting the old behavior can use a prefix and then a  
meta-command like "\set HISTSIZE :prefix_HISTSIZE".  Back-patch to 9.5  
(all supported versions).  
  
Reviewed by Robert Haas.  Reported by Nick Cleaton.  
  
Security: CVE-2020-25696  

commit   : ff3de4c21a462f2da773848c53faedac88d6e54d    
  
author   : Noah Misch <[email protected]>    
date     : Mon, 9 Nov 2020 07:32:09 -0800    
  
committer: Noah Misch <[email protected]>    
date     : Mon, 9 Nov 2020 07:32:09 -0800    

Specifically, this blocks DECLARE ... WITH HOLD and firing of deferred  
triggers within index expressions and materialized view queries.  An  
attacker having permission to create non-temp objects in at least one  
schema could execute arbitrary SQL functions under the identity of the  
bootstrap superuser.  One can work around the vulnerability by disabling  
autovacuum and not manually running ANALYZE, CLUSTER, REINDEX, CREATE  
INDEX, VACUUM FULL, or REFRESH MATERIALIZED VIEW.  (Don't restore from  
pg_dump, since it runs some of those commands.)  Plain VACUUM (without  
FULL) is safe, and all commands are fine when a trusted user owns the  
target object.  Performance may degrade quickly under this workaround,  
however.  Back-patch to 9.5 (all supported versions).  
  
Reviewed by Robert Haas.  Reported by Etienne Stalmans.  
  
Security: CVE-2020-25695  

commit   : d8a9722bd39c4eced4b13551f0401b37ff72ef74    
  
author   : Peter Eisentraut <[email protected]>    
date     : Mon, 9 Nov 2020 12:47:52 +0100    
  
committer: Peter Eisentraut <[email protected]>    
date     : Mon, 9 Nov 2020 12:47:52 +0100    

Source-Git-URL: https://git.postgresql.org/git/pgtranslation/messages.git  
Source-Git-Hash: f09d69720b2d48f37d3b555c38501b6529c0c6ac  

commit   : 7ebea4e224ca826e6c7abc6c682701485cd634f6    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 8 Nov 2020 16:22:39 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 8 Nov 2020 16:22:39 -0500    

Fractional colwidths seem not to work in the openjade toolchain.  
Since we have no colwidth specs anywhere else in pre-v10 branches,  
let's just drop the ones introduced by commits ee59f669b/35b12948a.  

commit   : a39e23b8c8d7ae0744619a5e7a14bcc907b696f9    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 8 Nov 2020 15:16:12 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 8 Nov 2020 15:16:12 -0500    

commit   : 8096be26178befa690841e449abb39e134f8d415    
  
author   : Peter Eisentraut <[email protected]>    
date     : Sat, 7 Nov 2020 22:15:52 +0100    
  
committer: Peter Eisentraut <[email protected]>    
date     : Sat, 7 Nov 2020 22:15:52 +0100    

A few client tools duplicate error messages already provided by libpq.  
  
Discussion: https://www.postgresql.org/message-id/flat/3e937641-88a1-e697-612e-99bba4b8e5e4%40enterprisedb.com  

commit   : bae31e75f7777f2398eccbd40c5676e3dd487d1a    
  
author   : Tomas Vondra <[email protected]>    
date     : Sat, 7 Nov 2020 00:41:36 +0100    
  
committer: Tomas Vondra <[email protected]>    
date     : Sat, 7 Nov 2020 00:41:36 +0100    

brin_form_tuple failed to consider the values may be toasted, inserting  
the toast pointer into the index. This may easily result in index  
corruption, as the toast data may be deleted and cleaned up by vacuum.  
The cleanup however does not care about indexes, leaving invalid toast  
pointers behind, which triggers errors like this:  
  
  ERROR:  missing chunk number 0 for toast value 16433 in pg_toast_16426  
  
A less severe consequence are inconsistent failures due to the index row  
being too large, depending on whether brin_form_tuple operated on plain  
or toasted version of the row. For example  
  
    CREATE TABLE t (val TEXT);  
    INSERT INTO t VALUES ('... long value ...')  
    CREATE INDEX idx ON t USING brin (val);  
  
would likely succeed, as the row would likely include toast pointer.  
Switching the order of INSERT and CREATE INDEX would likely fail:  
  
    ERROR:  index row size 8712 exceeds maximum 8152 for index "idx"  
  
because this happens before the row values are toasted.  
  
The bug exists since PostgreSQL 9.5 where BRIN indexes were introduced.  
So backpatch all the way back.  
  
Author: Tomas Vondra  
Reviewed-by: Alvaro Herrera  
Backpatch-through: 9.5  
Discussion: https://postgr.es/m/20201001184133.oq5uq75sb45pu3aw@development  
Discussion: https://postgr.es/m/20201104010544.zexj52mlldagzowv%40development  

commit   : 9e555180f23dd4d1a85a8b2b93350358322a540a    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 6 Nov 2020 16:17:57 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 6 Nov 2020 16:17:57 -0500    

Revert 59ab4ac32, as well as the followup fix 33862cb9c, in all  
branches.  We need to think a bit harder about what the behavior  
of LOCK TABLE on views should be, and there's no time for that  
before next week's releases.  We'll take another crack at this  
later.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 768ab4d676aa84cfcb8f59e843e4e97559b6cc5e    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 6 Nov 2020 15:48:21 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 6 Nov 2020 15:48:21 -0500    

Revert 403a3d91c, as well as the followup fix 7f4235032, in all  
branches.  We need to think a bit harder about what the behavior  
of LOCK TABLE on views should be, and there's no time for that  
before next week's releases.  We'll take another crack at this  
later.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 583fcf2f57594cc73fe537b2bf18cfbc6b13336f    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 6 Nov 2020 12:14:46 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 6 Nov 2020 12:14:46 -0500    

Commits 59ab4ac32 et al mistakenly copied-and-pasted some text about  
how LOCK on a view recurses to referenced tables into pre-v11 branches,  
which in fact don't do that.  Undo that, and instead state clearly  
that they don't.  (I also chose to add a note that this behavior  
changed in v11.  We usually don't back-patch such statements, but  
since it's easy to add the warning now, might as well.)  
  
Noted while considering followup fixes for bug #16703.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 04c4b495b1c93c40bc989c450ca8fb5bea965e27    
  
author   : Tom Lane <[email protected]>    
date     : Tue, 3 Nov 2020 15:41:32 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Tue, 3 Nov 2020 15:41:32 -0500    

The intention in commit 491c029db was to require superuserness to  
change the BYPASSRLS property, but the actual effect of the coding  
in AlterRole() was to require superuserness to change anything at all  
about a BYPASSRLS role.  Other properties of a BYPASSRLS role should  
be changeable under the same rules as for a normal role, though.  
  
Fix that, and also take care of some documentation omissions related  
to BYPASSRLS and REPLICATION role properties.  
  
Tom Lane and Stephen Frost, per bug report from Wolfgang Walther.  
Back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : c6671cdbde93b9b344d182dcbedeebff745a67c8    
  
author   : Michael Paquier <[email protected]>    
date     : Mon, 2 Nov 2020 15:15:37 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Mon, 2 Nov 2020 15:15:37 +0900    

The documentation fixes are backpatched down to where they apply.  
  
Author: Justin Pryzby  
Discussion: https://postgr.es/m/[email protected]  
Backpatch-through: 9.6  

commit   : 1127377a578bde76ed09edd7cd5d8965365c8aaa    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 1 Nov 2020 11:26:16 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 1 Nov 2020 11:26:16 -0500    

Although error results received from the backend should always have  
a SQLSTATE field, ones generated by libpq won't, making this code  
vulnerable to a crash after, say, untimely loss of connection.  
Noted by Coverity.  
  
Oversight in commit 403a3d91c.  Back-patch to 9.5, as that was.  

commit   : 204d779695607eae5c6c0fa314516201b0af357f    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 28 Oct 2020 14:35:53 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 28 Oct 2020 14:35:53 -0400    

In almost all other places, we use plain "r" or "w" mode in popen()  
calls (the exceptions being for COPY data).  This one has been  
overlooked (possibly because it's buried in a ".l" flex file?),  
but it's using PG_BINARY_R.  
  
Kensuke Okamura complained in bug #16688 that we fail to strip \r  
when stripping the trailing newline from a backtick result string.  
That's true enough, but we'd also fail to convert embedded \r\n  
cleanly, which also seems undesirable.  Fixing the popen() mode  
seems like the best way to deal with this.  
  
It's been like this for a long time, so back-patch to all supported  
branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : cc623ed2f4ac09a97c5ef24dee28d91482ae2e13    
  
author   : Tom Lane <[email protected]>    
date     : Tue, 27 Oct 2020 15:37:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Tue, 27 Oct 2020 15:37:13 -0400    

EventTriggerAlterTableEnd neglected to make sure that it built its  
output list in the right context.  In simple cases this was masked  
because the function is called in PortalContext which will be  
sufficiently long-lived anyway; but that doesn't make it not a bug.  
Commit ced138e8c fixed this in HEAD and v13, but mistakenly chose  
not to back-patch further.  Back-patch the same code change all  
the way (I didn't bother with the test case though, as it would  
prove nothing in pre-v13 branches).  
  
Per report from Arseny Sher.  
Original fix by Jehan-Guillaume de Rorthais.  
  
Discussion: https://postgr.es/m/877drcyprb.fsf@ars-thinkpad  
Discussion: https://postgr.es/m/20200902193715.6e0269d4@firost  

commit   : 00e4788f206452168a1b9505c22956074722e930    
  
author   : Bruce Momjian <[email protected]>    
date     : Tue, 27 Oct 2020 14:00:38 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Tue, 27 Oct 2020 14:00:38 -0400    

You can't compile thread_test alone anymore, and the location moved too.  
  
Reported-by: Tom Lane  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : a575a1ab27ef8362f5e885b41092824929961288    
  
author   : Alvaro Herrera <[email protected]>    
date     : Tue, 27 Oct 2020 14:31:37 -0300    
  
committer: Alvaro Herrera <[email protected]>    
date     : Tue, 27 Oct 2020 14:31:37 -0300    

Now that LOCK TABLE can take any relation type, acquire lock on all  
relations that are to be dumped.  This prevents schema changes or  
deadlock errors that could cause a dump to fail after expending much  
effort.  The server is tested to have the capability and the feature  
disabled if it doesn't, so that a patched pg_dump doesn't fail when  
connecting to an unpatched server.  
  
Backpatch to 9.5.  
  
Author: Álvaro Herrera <[email protected]>  
Reviewed-by: Tom Lane <[email protected]>  
Reported-by: Wells Oliver <[email protected]>  
Discussion: https://postgr.es/m/[email protected]  

commit   : 53de141f975187621c1c50e473c562ee63cd9b36    
  
author   : Alvaro Herrera <[email protected]>    
date     : Tue, 27 Oct 2020 13:49:19 -0300    
  
committer: Alvaro Herrera <[email protected]>    
date     : Tue, 27 Oct 2020 13:49:19 -0300    

The restriction that only tables and views can be locked by LOCK TABLE  
is quite arbitrary, since the underlying mechanism can lock any relation  
type.  Drop the restriction so that programs such as pg_dump can lock  
all relations they're interested in, preventing schema changes that  
could cause a dump to fail after expending much effort.  
  
Backpatch to 9.5.  
  
Author: Álvaro Herrera <[email protected]>  
Reviewed-by: Tom Lane <[email protected]>  
Reported-by: Wells Oliver <[email protected]>  
Discussion: https://postgr.es/m/[email protected]  

commit   : 67b3c3b8c4cbe31d51bc7f68162054f2f33b185a    
  
author   : Bruce Momjian <[email protected]>    
date     : Tue, 27 Oct 2020 12:43:11 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Tue, 27 Oct 2020 12:43:11 -0400    

This directory and the ability to build the thread test independently  
were removed in commit 8a2121185b.  
  
Reported-by: [email protected]  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : 58947869528dad323196bf79bd0b08c52c5e33c5    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 26 Oct 2020 22:38:11 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 26 Oct 2020 22:38:11 -0400    

Reported-by: [email protected]  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : eb435768889467fb7e4bb84321f4347e25377e5a    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 26 Oct 2020 19:17:05 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 26 Oct 2020 19:17:05 -0400    

Parallel execution changed the way bloom queries are executed, so update  
the EXPLAIN output, and restructure the docs to be clearer and more  
accurate.  
  
Reported-by: Daniel Westermann  
  
Discussion: https://postgr.es/m/ZR0P278MB0122119FAE78721A694C30C8D2340@ZR0P278MB0122.CHEP278.PROD.OUTLOOK.COM  
  
Author: Daniel Westermann and me  
  
Backpatch-through: 9.6  

commit   : 379c43bdad1d18786b87f38e8761f61a478b5875    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 24 Oct 2020 13:12:08 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 24 Oct 2020 13:12:08 -0400    

We must not set the "done" flag until after we've executed the  
initialization function.  Otherwise, other threads can fall through  
the initial unlocked test before initialization is really complete.  
  
This has been seen to cause rare failures of ecpg's thread/descriptor  
test, and it could presumably cause other sorts of misbehavior in  
threaded ECPG-using applications, since ecpglib relies on  
pthread_once() in several places.  
  
Diagnosis and patch by me, based on investigation by Alexander Lakhin.  
Back-patch to all supported branches (the bug dates to 2007).  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 05a36321a70e180168cd58a2e20313163c007623    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 22 Oct 2020 21:23:47 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 22 Oct 2020 21:23:47 -0400    

DST law changes in Palestine, with a whopping 120 hours' notice.  
Also some historical corrections for Palestine.  

commit   : 58f9f52a3791e760550ac6a32aa085d3ed5ee667    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 22 Oct 2020 21:15:22 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 22 Oct 2020 21:15:22 -0400    

There's no functional change at all here, but I'm curious to see  
whether this change successfully shuts up Coverity's warning about  
a useless strcmp(), which appeared with the previous update.  
  
Discussion: http://mm.icann.org/pipermail/tz/2020-October/029370.html  

commit   : 870a2323033e8b96b27cdf65a53f3e0c7c7b9a88    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 21 Oct 2020 16:18:41 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 21 Oct 2020 16:18:41 -0400    

psql's \connect claims to be able to re-use previous connection  
parameters, but in fact it only re-uses the database name, user name,  
host name (and possibly hostaddr, depending on version), and port.  
This is problematic for assorted use cases.  Notably, pg_dump[all]  
emits "\connect databasename" commands which we would like to have  
re-use all other parameters.  If such a script is loaded in a psql run  
that initially had "-d connstring" with some non-default parameters,  
those other parameters would be lost, potentially causing connection  
failure.  (Thus, this is the same kind of bug addressed in commits  
a45bc8a4f and 8e5793ab6, although the details are much different.)  
  
To fix, redesign do_connect() so that it pulls out all properties  
of the old PGconn using PQconninfo(), and then replaces individual  
properties in that array.  In the case where we don't wish to re-use  
anything, get libpq's default settings using PQconndefaults() and  
replace entries in that, so that we don't need different code paths  
for the two cases.  
  
This does result in an additional behavioral change for cases where  
the original connection parameters allowed multiple hosts, say  
"psql -h host1,host2", and the \connect request allows re-use of the  
host setting.  Because the previous coding relied on PQhost(), it  
would only permit reconnection to the same host originally selected.  
Although one can think of scenarios where that's a good thing, there  
are others where it is not.  Moreover, that behavior doesn't seem to  
meet the principle of least surprise, nor was it documented; nor is  
it even clear it was intended, since that coding long pre-dates the  
addition of multi-host support to libpq.  Hence, this patch is content  
to drop it and re-use the host list as given.  
  
Per Peter Eisentraut's comments on bug #16604.  Back-patch to all  
supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : d4e654d15467d68c85e05eaaa49291de9f81b3ed    
  
author   : Peter Eisentraut <[email protected]>    
date     : Mon, 19 Oct 2020 08:52:25 +0200    
  
committer: Peter Eisentraut <[email protected]>    
date     : Mon, 19 Oct 2020 08:52:25 +0200    

In shm_mq_receive(), a huge payload could trigger an unjustified  
"invalid memory alloc request size" error due to the way the buffer  
size is increased.  
  
Add error checks (documenting the upper limit) and avoid the error by  
limiting the allocation size to MaxAllocSize.  
  
Author: Markus Wanner <[email protected]>  
Discussion: https://www.postgresql.org/message-id/flat/3bb363e7-ac04-0ac4-9fe8-db1148755bfa%402ndquadrant.com  

commit   : 5c78f797701b90546279b994791fc07af5bbb5c9    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 19 Oct 2020 19:03:47 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 19 Oct 2020 19:03:47 -0400    

When told to process all databases, clusterdb, reindexdb, and vacuumdb  
would reconnect by replacing their --maintenance-db parameter with the  
name of the target database.  If that parameter is a connstring (which  
has been allowed for a long time, though we failed to document that  
before this patch), we'd lose any other options it might specify, for  
example SSL or GSS parameters, possibly resulting in failure to connect.  
Thus, this is the same bug as commit a45bc8a4f fixed in pg_dump and  
pg_restore.  We can fix it in the same way, by using libpq's rules for  
handling multiple "dbname" parameters to add the target database name  
separately.  I chose to apply the same refactoring approach as in that  
patch, with a struct to handle the command line parameters that need to  
be passed through to connectDatabase.  (Maybe someday we can unify the  
very similar functions here and in pg_dump/pg_restore.)  
  
Per Peter Eisentraut's comments on bug #16604.  Back-patch to all  
supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 67a6af69870d1c95e6e78295849fee807ba5691b    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Mon, 19 Oct 2020 19:28:54 +0300    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Mon, 19 Oct 2020 19:28:54 +0300    

- Misc grammar and punctuation fixes.  
  
- Stylistic cleanup: use spaces between function arguments and JSON fields  
  in examples. For example "foo(a,b)" -> "foo(a, b)". Add semicolon after  
  last END in a few PL/pgSQL examples that were missing them.  
  
- Make sentence that talked about "..." and ".." operators more clear,  
  by avoiding to end the sentence with "..". That makes it look the same  
  as "..."  
  
- Fix syntax description for HAVING: HAVING conditions cannot be repeated  
  
Patch by Justin Pryzby, per Yaroslav Schekin's report. Backpatch to all  
supported versions, to the extent that the patch applies easily.  
  
Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com  

commit   : 07d46e7e077f5a1c1d6b5d7c9c8fff51c66d54e5    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Mon, 19 Oct 2020 18:50:33 +0300    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Mon, 19 Oct 2020 18:50:33 +0300    

The output for this query changed in commit 4e2477b7b8. Backport to 9.6  
like that commit.  
  
Patch by Justin Pryzby, per Yaroslav Schekin's report.  
  
Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com  

commit   : cdc7ace161d39ed788e4e169763c80b58d5bd9c1    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 19 Oct 2020 11:23:52 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 19 Oct 2020 11:23:52 -0400    

The Windows documentation insists that every WSAStartup call should  
have a matching WSACleanup call.  However, if that ever had actual  
relevance, it wasn't in this century.  Every remotely-modern Windows  
kernel is capable of cleaning up when a process exits without doing  
that, and must be so to avoid resource leaks in case of a process  
crash.  Moreover, Postgres backends have done WSAStartup without  
WSACleanup since commit 4cdf51e64 in 2004, and we've never seen any  
indication of a problem with that.  
  
libpq's habit of doing WSAStartup during connection start and  
WSACleanup during shutdown is also rather inefficient, since a  
series of non-overlapping connection requests leads to repeated,  
quite expensive DLL unload/reload cycles.  We document a workaround  
for that (having the application call WSAStartup for itself), but  
that's just a kluge.  It's also worth noting that it's far from  
uncommon for applications to exit without doing PQfinish, and  
we've not heard reports of trouble from that either.  
  
However, the real reason for acting on this is that recent  
experiments by Alexander Lakhin show that calling WSACleanup  
during PQfinish is triggering the symptom we occasionally see  
that a process using libpq fails to emit expected stdio output.  
  
Therefore, let's change libpq so that it calls WSAStartup only  
once per process, during the first connection attempt, and never  
calls WSACleanup at all.  
  
While at it, get rid of the only other WSACleanup call in our code  
tree, in pg_dump/parallel.c; that presumably is equally useless.  
  
Back-patch of HEAD commit 7d00a6b2d.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 8ae447e2f7cd1a60e715f624dc7fe1e1a768e7ab    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Mon, 19 Oct 2020 17:58:38 +0300    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Mon, 19 Oct 2020 17:58:38 +0300    

Commit 028350f619 changed its behavior from "at most" to "exactly", but  
forgot to update the documentation. Backpatch to 9.6.  
  
Patch by Justin Pryzby, per Yaroslav Schekin's report.  
  
Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com  

commit   : 00fecc24c140b965e0bdd00942f07f0d43983d7d    
  
author   : David Rowley <[email protected]>    
date     : Tue, 20 Oct 2020 00:03:16 +1300    
  
committer: David Rowley <[email protected]>    
date     : Tue, 20 Oct 2020 00:03:16 +1300    

In the planner, it was possible, given an extreme enough case containing a  
large number of joins for the number of estimated rows to become infinite.  
This could cause problems in initial_cost_mergejoin() where we perform  
some calculations based on those row estimates.  
  
A problem case, presented by Onder Kalaci showed an Assert failure from  
an Assert checking outerstartsel <= outerendsel.  In his test case this  
was effectively NaN <= Inf, which is false.  The NaN outerstartsel came  
from multiplying the infinite outer_path_rows by 0.0.  
  
In master, this problem was fixed by a90c950fc, however, that fix was too  
invasive for the backbranches.  Here we just relax the Asserts to allow  
them to pass.  The worst that appears to happen from this is that we show  
NaN cost values and infinite row estimates in EXPLAIN.  add_path() would  
have had a hard time doing anything useful with such costs, but that does  
not really matter as if the row estimates were even close to accurate,  
such plan would not complete this side of the heat death of the universe.  
  
Reported-by: Onder Kalaci  
Backpatch: 9.5 to 13  
Discussion: https://postgr.es/m/DM6PR21MB1211FF360183BCA901B27F04D80B0@DM6PR21MB1211.namprd21.prod.outlook.com  

commit   : 994a02f7f77c760db5c28aa9f34c7e7fd88993cf    
  
author   : Michael Paquier <[email protected]>    
date     : Mon, 19 Oct 2020 09:38:13 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Mon, 19 Oct 2020 09:38:13 +0900    

When allocating a EVP context, it would have been possible to leak some  
memory allocated directly by OpenSSL, that PostgreSQL lost track of if  
the initialization of the context allocated failed.  The cleanup can be  
done with EVP_MD_CTX_destroy().  
  
Note that EVP APIs exist since OpenSSL 0.9.7 and we have in the tree  
equivalent implementations for older versions since ce9b75d (code  
removed with 9b7cd59a as of 10~).  However, in 9.5 and 9.6, the existing  
code makes use of EVP_MD_CTX_destroy() and EVP_MD_CTX_create() without  
an equivalent implementation when building the tree with OpenSSL 0.9.6  
or older, meaning that this code is in reality broken with such versions  
since it got introduced in e2838c5.  As we have heard no complains about  
that, it does not seem worth bothering with in 9.5 and 9.6, so I have  
left that out for simplicity.  
  
Author: Michael Paquier  
Discussion: https://postgr.es/m/[email protected]  
Backpatch-through: 9.5  

commit   : c1a3188baeda2414a7a7453917d73aa5db511067    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 17 Oct 2020 16:02:47 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 17 Oct 2020 16:02:47 -0400    

Section 8.5.1.4, which defines these literals, made only a vague  
reference to the fact that they might be evaluated too soon to be  
safe in non-interactive contexts.  Provide a more explicit caution  
against misuse.  Also, generalize the wording in the related tip in  
section 9.9.4: while it clearly described this problem, it implied  
(or really, stated outright) that the problem only applies to table  
DEFAULT clauses.  
  
Per gripe from Tijs van Dam.  Back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/c2LuRv9BiRT3bqIo5mMQiVraEXey_25B4vUn0kDqVqilwOEu_iVF1tbtvLnyQK7yDG3PFaz_GxLLPil2SDkj1MCObNRVaac-7j1dVdFERk8=@thalex.com  

commit   : 13dbf4ab82ea4ebe32aa178fcc7535f95a08de2f    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 16 Oct 2020 21:53:33 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 16 Oct 2020 21:53:33 -0400    

DST law changes in Morocco, Canadian Yukon, Fiji, Macquarie Island,  
Casey Station (Antarctica).  Historical corrections for France,  
Hungary, Monaco.  

commit   : 5515c73a610568e9572e01137a0153a98c1f6088    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 16 Oct 2020 21:40:16 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 16 Oct 2020 21:40:16 -0400    

This changes zic's default output format from "-b fat" to "-b slim".  
We were already using "slim" in v13/HEAD, so those branches drop  
the explicit -b switch in the Makefiles.  Instead, add an explicit  
"-b fat" in v12 and before, so that we don't change the output file  
format in those branches.  (This is perhaps excessively conservative,  
but we decided not to do so in a12079109, and I'll stick with that.)  
  
Other non-cosmetic changes are to drop support for zic's long-obsolete  
"-y" switch, and to ensure that strftime() does not change errno  
unless it fails.  
  
As usual with tzcode changes, back-patch to all supported branches.  

commit   : e15115b4d204989447203b12b905c66dfb6c0a78    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 16 Oct 2020 11:59:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 16 Oct 2020 11:59:13 -0400    

In theory, the second px_find_digest call in px_crypt_md5 could fail  
even though the first one succeeded, since resource allocation is  
required.  Don't skip testing for a failure.  (If one did happen,  
the likely result would be a crash rather than clean recovery from  
an OOM failure.)  
  
The code's been like this all along, so back-patch to all supported  
branches.  
  
Daniel Gustafsson  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 35b12948ac880a3adcf61be1297809b9c19f34d3    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 16 Oct 2020 11:36:34 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 16 Oct 2020 11:36:34 -0400    

Commit a97e85f2b caused "exceed the available area" warnings in PDF  
builds.  Fine-tune colwidth values to avoid that.  
  
Back-patch to 9.6, like the prior patch.  (This is of dubious value  
before v13, since we were far from free of such warnings in older  
branches.  But we might as well keep the SGML looking the same in all  
branches.)  
  
Per buildfarm.  

commit   : 9dcffe69a93183bba607527279270eac486463e8    
  
author   : Bruce Momjian <[email protected]>    
date     : Thu, 15 Oct 2020 20:37:19 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Thu, 15 Oct 2020 20:37:19 -0400    

This commit required support for inline variable definition, which is  
not a requirement.  
  
RELEASE NOTE AUTHOR:  the author of commit 3c0471b5fd  
(pg_upgrade/tablespaces) was Justin Pryzby, not me.  
  
Reported-by: Andres Freund  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : 39c23c199d0aec58d0018a2ca52cbccbf8ea18e4    
  
author   : Bruce Momjian <[email protected]>    
date     : Thu, 15 Oct 2020 19:33:36 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Thu, 15 Oct 2020 19:33:36 -0400    

Previously, if pg_upgrade failed, and the user recreated the cluster but  
did not remove the new cluster tablespace directory, a later pg_upgrade  
would fail since the new tablespace directory would already exists.  
This adds error reporting for this during check.  
  
Reported-by: Justin Pryzby  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : ee59f669b666e62b7e769ece97ef74ef621acd8d    
  
author   : Bruce Momjian <[email protected]>    
date     : Thu, 15 Oct 2020 15:15:28 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Thu, 15 Oct 2020 15:15:28 -0400    

Previously it wasn't clear exactly what each of the synchronous_commit  
modes accomplished.  This clarifies that, and adds a table describing it.  
Only backpatched through 9.6 since 9.5 doesn't have all the options.  
  
Reported-by: [email protected]  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.6  

commit   : 7753ca49d3580454fc55df0ef77cfa87621b56e3    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 15 Oct 2020 12:50:57 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 15 Oct 2020 12:50:57 -0400    

POSIX sigaction(2) can be told to block a set of signals while a  
signal handler executes.  Make use of that instead of manually  
blocking and unblocking signals in the postmaster's signal handlers.  
This should save a few cycles, but more importantly it prevents  
recursive invocation of signal handlers when many signals arrive in  
close succession.  (Assuming that the platform's signal infrastructure  
is designed to avoid consuming stack space in that case, but this is  
demonstrably true at least on Linux.)  The existing code has been seen  
to recurse to the point of stack overflow, either in the postmaster  
or in a forked-off child.  
  
Back-patch of commit 9abb2bfc0.  At the time, we'd only seen excess  
postmaster stack consumption in the buildfarm; but we now have a  
user report of it, and that commit has aged enough to have a fair  
amount of confidence that it doesn't break anything.  
  
This still doesn't change anything about the way that it works on  
Windows.  Perhaps someone else would like to fix that?  
  
Per bug #16673 from David Geier.  Back-patch to 9.6.  Although  
the problem exists in principle before that, we've only seen it  
actually materialize in connection with heavy use of parallel  
workers, so it doesn't seem necessary to do anything in 9.5;  
and the relevant code is different there, too.  
  
Discussion: https://postgr.es/m/[email protected]  
Discussion: https://postgr.es/m/[email protected]  

commit   : c7573ab1eca766591ca6fbb1dc64067540094c62    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 12 Oct 2020 13:31:24 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 12 Oct 2020 13:31:24 -0400    

The prohibitValueChange code paths in set_config_option(), which  
are executed whenever we re-read a PGC_POSTMASTER variable from  
postgresql.conf, neglected to free anything before exiting.  Thus  
we'd leak the proposed new value of a PGC_STRING variable, as noted  
by BoChen in bug #16666.  For all variable types, if the check hook  
creates an "extra" chunk, we'd also leak that.  
  
These are malloc not palloc chunks, so there is no mechanism for  
recovering the leaks before process exit.  Fortunately, the values  
are typically not very large, meaning you'd have to go through an  
awful lot of SIGHUP configuration-reload cycles to make the leakage  
amount to anything.  Still, for a long-lived postmaster process it  
could potentially be a problem.  
  
Oversight in commit 2594cf0e8.  Back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : eb48619d01d77d8273f4effa64f7ad544db8bb35    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 7 Oct 2020 18:41:39 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 7 Oct 2020 18:41:39 -0400    

It appears that commit cf63c641c, which intended to prevent  
misoptimization of the result-building step in makeOrderedSetArgs,  
didn't go far enough: buildfarm member hornet's version of xlc  
is now optimizing back to the old, broken behavior in which  
list_length(directargs) is fetched only after list_concat() has  
changed that value.  I'm not entirely convinced whether that's  
an undeniable compiler bug or whether it can be justified by a  
sufficiently aggressive interpretation of C sequence points.  
So let's just change the code to make it harder to misinterpret.  
  
Back-patch to all supported versions, just in case.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 710c0a66d6e9cc2817f6b7e8ad694498bafca843    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 7 Oct 2020 12:50:55 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 7 Oct 2020 12:50:55 -0400    

Commit 3eb3d3e78 was a few bricks shy of a load: while it correctly  
set the table's "interesting" flag when deciding to dump the data of  
an extension config table, it was not correct to clear that flag  
if we concluded we shouldn't dump the data.  This led to the crash  
reported in bug #16655, because in fact we'll traverse dumpTableSchema  
anyway for all extension tables (to see if they have user-added  
seclabels or RLS policies).  
  
The right thing to do is to force "interesting" true in makeTableDataInfo,  
and otherwise leave the flag alone.  (Doing it there is more future-proof  
in case additional calls are added, and it also avoids setting the flag  
unnecessarily if that function decides the table is non-dumpable.)  
  
This investigation also showed that while only the --inserts code path  
had an obvious failure in the case considered by 3eb3d3e78, the COPY  
code path also has a problem with not having loaded table subsidiary  
data.  That causes fmtCopyColumnList to silently return an empty string  
instead of the correct column list.  That accidentally mostly works,  
which perhaps is why we didn't notice this before.  It would only fail  
if the restore column order is different from the dump column order,  
which only happens in weird inheritance cases, so it's not surprising  
nobody had hit the case with an extension config table.  Nonetheless,  
it's a bug, and it goes a long way back, not just to v12 where the  
--inserts code path started to have a problem with this.  
  
In hopes of catching such cases a bit sooner in future, add some  
Asserts that "interesting" has been set in both dumpTableData and  
dumpTableSchema.  Adjust the test case added by 3eb3d3e78 so that it  
checks the COPY rather than INSERT form of that bug, allowing it to  
detect the longer-standing symptom.  
  
Per bug #16655 from Cameron Daniel.  Back-patch to all supported  
branches.  
  
Discussion: https://postgr.es/m/[email protected]  
Discussion: https://postgr.es/m/[email protected]  

commit   : 700b7002f2727cd1f9e01c5def6023b78017b958    
  
author   : Bruce Momjian <[email protected]>    
date     : Tue, 6 Oct 2020 14:31:21 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Tue, 6 Oct 2020 14:31:21 -0400    

We only support upgrading from >= 8.4 so no need for this code or tests.  
  
Reported-by: Magnus Hagander  
  
Discussion: https://postgr.es/m/CABUevEx-D0PNVe00tkeQRGennZQwDtBJn=493MJt-x6sppbUxA@mail.gmail.com  
  
Backpatch-through: 9.5  

commit   : 0e78dcaf73b6b9d4c74b858ebb4a0464b7c726de    
  
author   : Bruce Momjian <[email protected]>    
date     : Tue, 6 Oct 2020 12:12:09 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Tue, 6 Oct 2020 12:12:09 -0400    

This makes checking for older major versions more consistent.  
  
Backpatch-through: 9.5  

commit   : 997188b6e0a11c60ddab369969ea2e57202941b8    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 5 Oct 2020 16:27:33 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 5 Oct 2020 16:27:33 -0400    

Previously it was unclear exactly how ROWS FROM behaved and how to cast  
the data types of columns returned by FROM functions.  Also document  
that only non-OUT record functions can have their columns cast to data  
types.  
  
Reported-by: [email protected]  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : f6a23344f8c8ec155399375d048a890afaa575ab    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 5 Oct 2020 13:15:39 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 5 Oct 2020 13:15:39 -0400    

get_eclass_for_sort_expr() computes expr_relids and nullable_relids  
early on, even though they won't be needed unless we make a new  
EquivalenceClass, which we often don't.  Aside from the probably-minor  
inefficiency, there's a memory management problem: these bitmapsets will  
be built in the caller's context, leading to dangling pointers if that  
is shorter-lived than root->planner_cxt.  This would be a live bug if  
get_eclass_for_sort_expr() could be called with create_it = true during  
GEQO join planning.  So far as I can find, the core code never does  
that, but it's hard to be sure that no extensions do, especially since  
the comments make it clear that that's supposed to be a supported case.  
Fix by not computing these values until we've switched into planner_cxt  
to build the new EquivalenceClass.  
  
generate_join_implied_equalities() uses inner_rel->relids to look up  
relevant eclasses, but it ought to be using nominal_inner_relids.  
This is presently harmless because a child RelOptInfo will always have  
exactly the same eclass_indexes as its topmost parent; but that might  
not be true forever, and anyway it makes the code confusing.  
  
The first of these is old (introduced by me in f3b3b8d5b), so back-patch  
to all supported branches.  The second only dates to v13, but we might  
as well back-patch it to keep the code looking similar across branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : cf42550d513169b3687785015d241c87b9cf87cd    
  
author   : Bruce Momjian <[email protected]>    
date     : Fri, 2 Oct 2020 22:19:30 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Fri, 2 Oct 2020 22:19:30 -0400    

Reported-by: Alexander Lakhin  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : d449ec6d52fc257e9f35b9841dbe98b92845faee    
  
author   : Bruce Momjian <[email protected]>    
date     : Fri, 2 Oct 2020 21:39:33 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Fri, 2 Oct 2020 21:39:33 -0400    

Reported-by: [email protected]  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : 19e7982681df74e20aa062d5605cb0f7e04c5d51    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 30 Sep 2020 15:40:23 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 30 Sep 2020 15:40:23 -0400    

Previously, a conversion such as  
	to_date('-44-02-01','YYYY-MM-DD')  
would result in '0045-02-01 BC', as the code attempted to interpret  
the negative year as BC, but failed to apply the correction needed  
for our internal handling of BC years.  Fix the off-by-one problem.  
  
Also, arrange for the combination of a negative year and an  
explicit "BC" marker to cancel out and produce AD.  This is how  
the negative-century case works, so it seems sane to do likewise.  
  
Continue to read "year 0000" as 1 BC.  Oracle would throw an error,  
but we've accepted that case for a long time so I'm hesitant to  
change it in a back-patch.  
  
Per bug #16419 from Saeed Hubaishan.  Back-patch to all supported  
branches.  
  
Dar Alathar-Yemen and Tom Lane  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 7be02a3bf03a8bec605d089f34ceb5f441e754a6    
  
author   : Fujii Masao <[email protected]>    
date     : Tue, 29 Sep 2020 16:21:46 +0900    
  
committer: Fujii Masao <[email protected]>    
date     : Tue, 29 Sep 2020 16:21:46 +0900    

Previously the standby server didn't archive timeline history files  
streamed from the primary even when archive_mode is set to "always",  
while it archives the streamed WAL files. This could cause the PITR to  
fail because there was no required timeline history file in the archive.  
The cause of this issue was that walreceiver didn't mark those files as  
ready for archiving.  
  
This commit makes walreceiver mark those streamed timeline history  
files as ready for archiving if archive_mode=always. Then the archiver  
process archives the marked timeline history files.  
  
Back-patch to all supported versions.  
  
Reported-by: Grigory Smolkin  
Author: Grigory Smolkin, Fujii Masao  
Reviewed-by: David Zhang, Anastasia Lubennikova  
Discussion: https://postgr.es/m/[email protected]  

commit   : acab757ce9ead47a39b4d2d25b91ed2532b8444a    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 26 Sep 2020 16:04:06 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 26 Sep 2020 16:04:06 -0400    

This function leaked some memory while loading qual clauses for  
an RLS policy.  While ordinarily negligible, that could build up  
in some repeated-reload cases, as reported by Konstantin Knizhnik.  
We can improve matters by borrowing the coding long used in  
RelationBuildRuleLock: build stringToNode's result directly in  
the target context, and remember to explicitly pfree the  
input string.  
  
This patch by no means completely guarantees zero leaks within  
this function, since we have no real guarantee that the catalog-  
reading subroutines it calls don't leak anything.  However,  
practical tests suggest that this is enough to resolve the issue.  
In any case, any remaining leaks are similar to those risked by  
RelationBuildRuleLock and other relcache-loading subroutines.  
If we need to fix them, we should adopt a more global approach  
such as that used by the RECOVER_RELATION_BUILD_MEMORY hack.  
  
While here, let's remove the need for an expensive PG_TRY block by  
using MemoryContextSetParent to reparent an initially-short-lived  
context for the RLS data.  
  
Back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 7c154f2fd246f7a5be40f3c6780b84e5eaba08de    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 24 Sep 2020 18:19:39 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 24 Sep 2020 18:19:39 -0400    

Parallel pg_dump failed if its -d parameter was a connection string  
containing any essential information other than host, port, or username.  
The same was true for pg_restore with --create.  
  
The reason is that these scenarios failed to preserve the connection  
string from the command line; the code felt free to replace that with  
just the database name when reconnecting from a pg_dump parallel worker  
or after creating the target database.  By chance, parallel pg_restore  
did not suffer this defect, as long as you didn't say --create.  
  
In practice it seems that the error would be obvious only if the  
connstring included essential, non-default SSL or GSS parameters.  
This may explain why it took us so long to notice.  (It also makes  
it very difficult to craft a regression test case illustrating the  
problem, since the test would fail in builds without those options.)  
  
Fix by refactoring so that ConnectDatabase always receives all the  
relevant options directly from the command line, rather than  
reconstructed values.  Inject a different database name, when necessary,  
by relying on libpq's rules for handling multiple "dbname" parameters.  
  
While here, let's get rid of the essentially duplicate _connectDB  
function, as well as some obsolete nearby cruft.  
  
Per bug #16604 from Zsolt Ero.  Back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : d38e15979ba484380cc3c54648e4985d44fb0b5e    
  
author   : Thomas Munro <[email protected]>    
date     : Thu, 24 Sep 2020 09:26:09 +1200    
  
committer: Thomas Munro <[email protected]>    
date     : Thu, 24 Sep 2020 09:26:09 +1200    

Harmonize behavior by moving reponsibility for fsyncing directories down  
into slru.c.  In 10 and later, only the multixact directories were  
missed (see commit 1b02be21), and in older branches all SLRUs were  
missed.  
  
Back-patch to all supported releases.  
  
Reviewed-by: Andres Freund <[email protected]>  
Reviewed-by: Michael Paquier <[email protected]>  
Discussion: https://postgr.es/m/CA%2BhUKGLtsTUOScnNoSMZ-2ZLv%2BwGh01J6kAo_DM8mTRq1sKdSQ%40mail.gmail.com  

commit   : b1fbb7d08f22290d63d7918274d55a5b8e364be3    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 23 Sep 2020 11:36:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 23 Sep 2020 11:36:13 -0400    

tsearch_readline() saves the string pointer it returns to the caller  
for possible use in the associated error context callback.  However,  
the caller will usually pfree that string sometime before it next  
calls tsearch_readline(), so that there is a window where an ereport  
will try to print an already-freed string.  
  
The built-in users of tsearch_readline() happen to all do that pfree  
at the bottoms of their loops, so that the window is effectively  
empty for them.  However, this is not documented as a requirement,  
and contrib/dict_xsyn doesn't do it like that, so it seems likely  
that third-party dictionaries might have live bugs here.  
  
The practical consequences of this seem pretty limited in any case,  
since production builds wouldn't clobber the freed string immediately,  
besides which you'd not expect syntax errors in dictionary files  
being used in production.  Still, it's clearly a bug waiting to bite  
somebody.  
  
Fix by pstrdup'ing the string to be saved for the error callback,  
and then pfree'ing it next time through.  It's been like this for  
a long time, so back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 1e00333ffa2eebd4cd76526dbd087bee3b96a015    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 18 Sep 2020 18:03:44 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 18 Sep 2020 18:03:44 -0400    

These two SQL functions are aliases for the same C function, so this  
change has no semantic effect.  However, because we dropped the  
numeric_fac alias in HEAD (commit 76f412ab3), operator definitions  
based on that one don't port forward, causing problems for cross-version  
upgrade tests based on the regression database.  
  
Patch all active back branches to dodge the problem.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : e09391a0a042a631de05faa195aea86acc66ba43    
  
author   : Noah Misch <[email protected]>    
date     : Sun, 13 Sep 2020 23:13:44 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Sun, 13 Sep 2020 23:13:44 -0700    

The test failed when something added WAL between pg_switch_wal() and  
pg_current_wal_lsn(), seen on buildfarm members hornet and sungazer.  
Fix v10, v9.6 and v9.5 by making this code mirror its v13+ counterpart.  
v12 and v11 lack a counterpart.  

commit   : 1a9c93ec3b9ae2766b60e97957d07028e2828796    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 13 Sep 2020 12:51:21 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 13 Sep 2020 12:51:21 -0400    

transformCreateStmt() adjusts the transformed statement's RangeVar  
to specify the target schema explicitly, for the express reason  
of making sure that auxiliary statements derived by parse  
transformation operate on the right table.  But the refactoring  
I did in commit 502898192 got this wrong and passed the untransformed  
RangeVar to expandTableLikeClause().  This could lead to assertion  
failures or weird misbehavior if the wrong table was accessed.  
  
Per report from Alexander Lakhin.  Like the previous patch, back-patch  
to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : dc71c640985fd07b2e2ff3df7e57752a44e828ed    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 10 Sep 2020 12:06:26 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 10 Sep 2020 12:06:26 -0400    

Bring the signal handling for startup-packet collection into line  
with the policy established in commits bedadc732 and 8e19a8264,  
namely don't risk running atexit callbacks when handling SIGQUIT.  
  
Ideally, we'd not do so for SIGTERM or timeout interrupts either,  
but that change seems a bit too risky for the back branches.  
For now, just improve the comments in this area to describe the risk.  
  
Also relocate where BackendInitialize re-disables these interrupts,  
to minimize the code span where they're active.  This doesn't buy  
a whole lot of safety, but it can't hurt.  
  
In passing, rename startup_die() to remove confusion about whether  
it is for the startup process.  
  
Like the previous commits, back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 4f737ca15b92abd4081cf400da2d4498154ae106    
  
author   : Magnus Hagander <[email protected]>    
date     : Thu, 10 Sep 2020 14:15:26 +0200    
  
committer: Magnus Hagander <[email protected]>    
date     : Thu, 10 Sep 2020 14:15:26 +0200    

Reported-by: Robert Kahlert  
Author: Daniel Gustafsson  

commit   : a4c0dbc447c7c42e1483e2d3bcc0856a5b9ba5dd    
  
author   : Michael Paquier <[email protected]>    
date     : Thu, 10 Sep 2020 15:51:00 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Thu, 10 Sep 2020 15:51:00 +0900    

Some comments are fixed while on it.  
  
Author: Justin Pryzby  
Discussion: https://postgr.es/m/[email protected]  
Backpatch-through: 9.6  

commit   : b2eaddd9b00acad80d634ec671235a080269bd72    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 9 Sep 2020 15:32:34 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 9 Sep 2020 15:32:34 -0400    

Commit 8e19a8264 changed the SIGQUIT handlers of almost all server  
processes not to run atexit callbacks.  The archiver process was  
skipped, perhaps because it's not connected to shared memory; but  
it's just as true here that running atexit callbacks in a signal  
handler is unsafe.  So let's make it work like the rest.  
  
In HEAD and v13, we can use the common SignalHandlerForCrashExit  
handler.  Before that, just tweak pgarch_exit to use _exit(2)  
explicitly.  
  
Like the previous commit, back-patch to all supported branches.  
  
Kyotaro Horiguchi, back-patching by me  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 27acbd51e60c98cba6441d7a88210a1c33bf9db4    
  
author   : Peter Eisentraut <[email protected]>    
date     : Tue, 8 Sep 2020 10:09:43 +0200    
  
committer: Peter Eisentraut <[email protected]>    
date     : Tue, 8 Sep 2020 10:09:43 +0200    

Using exit() requires stdlib.h, which is not included.  Use return  
instead.  Also add return type for main().  
  
Reviewed-by: Heikki Linnakangas <[email protected]>  
Reviewed-by: Thomas Munro <[email protected]>  
  
Backpatched because Apple macOS 10.16/11 (Big Sur) compiler makes  
calling undeclared functions an error, so these configure tests would  
fail.  
  
Reported-by: Thomas Gilligan <[email protected]>  
Reported-by: Jesse Zhang <[email protected]>  
Reviewed-by: Tom Lane <[email protected]>  
Discussion: https://www.postgresql.org/message-id/flat/09A4B554-82B1-4536-B191-2461342EE0BB%40icloud.com  

commit   : 2939f613fa91f12b43d51eb8c4e595d5164e5254    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 6 Sep 2020 12:55:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 6 Sep 2020 12:55:13 -0400    

We reported the wrong types when complaining that an aggregate's  
moving-aggregate implementation is inconsistent with its regular  
implementation.  
  
This was wrong since the feature was introduced, so back-patch  
to all supported branches.  
  
Jeff Janes  
  
Discussion: https://postgr.es/m/CAMkU=1x808LH=LPhZp9mNSP0Xd1xDqEd+XeGcvEe48dfE6xV=A@mail.gmail.com  

commit   : 1f8c163c5acdef34dff14615337332cecc21d70b    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 6 Sep 2020 11:50:41 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 6 Sep 2020 11:50:41 -0400    

This is duplicative of an lstat that was just done by the calling  
function (traverse_datadir), besides which we weren't really doing  
anything with the results.  There's not much point in checking to  
see if someone removed the file since the previous lstat, since the  
FILE_ACTION_REMOVE code would have to deal with missing-file cases  
anyway.  Moreover, the "exists = false" assignment was a dead store;  
nothing was done with that value later.  
  
A syscall saved is a syscall earned, so back-patch to 9.5  
where this code was introduced.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 7f79f9582185eb7086ac3c59fa79b47a37cd7d7a    
  
author   : Bruce Momjian <[email protected]>    
date     : Fri, 4 Sep 2020 13:27:52 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Fri, 4 Sep 2020 13:27:52 -0400    

Reported-by: Kelly Min  
  
Discussion: https://postgr.es/m/CAPSbxatOiQO90LYpSC3+svAU9-sHgDfEP4oFhcEUt_X=DqFA9g@mail.gmail.com  
  
Backpatch-through: 9.5  

commit   : b2fcaed66a4aa88331b375409ef208b12f97c144    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 4 Sep 2020 12:40:28 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 4 Sep 2020 12:40:28 -0400    

The "DROP ACCESS METHOD gist2" test will require locking the index  
to be dropped and then its table; while most ordinary operations  
lock a table first then its index.  While no concurrent test scripts  
should be touching fast_emp4000, autovacuum might chance to be  
processing that table when the DROP runs, resulting in a deadlock  
failure.  This is pretty rare but we see it in the buildfarm from  
time to time.  
  
To fix, acquire a lock on fast_emp4000 before issuing the DROP.  
  
Since the point of the exercise is mostly to prevent buildfarm  
failures, back-patch to 9.6 where this test was introduced.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 2500e51e7bdc6c4f01312db276d3460644684112    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 3 Sep 2020 16:52:09 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 3 Sep 2020 16:52:09 -0400    

Because sigsetjmp() will restore the initial state with signals blocked,  
the code path in bgworker.c for reporting an error and exiting would  
execute that way.  Usually this is fairly harmless; but if a parallel  
worker had an error message exceeding the shared-memory communication  
buffer size (16K) it would lock up, because it would wait for a  
resume-sending signal from its parallel leader which it would never  
detect.  
  
To fix, just unblock signals at the appropriate point.  
  
This can be shown to fail back to 9.6.  The lack of parallel query  
infrastructure makes it difficult to provide a simple test case for  
9.5; but I'm pretty sure the issue exists in some form there as well,  
so apply the code change there too.  
  
Vignesh C, reviewed by Bharath Rupireddy, Robert Haas, and myself  
  
Discussion: https://postgr.es/m/CALDaNm1d1hHPZUg3xU4XjtWBOLCrA+-2cJcLpw-cePZ=GgDVfA@mail.gmail.com  

commit   : 34071aa1a23a949eecd49c6c765e14bf057cacb0    
  
author   : Bruce Momjian <[email protected]>    
date     : Tue, 1 Sep 2020 17:00:09 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Tue, 1 Sep 2020 17:00:09 -0400    

Previous wording was "between".  
  
Reported-by: Pavel Luzanov  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : ba23174dd9163b9ebc48791f57e45fae727f8922    
  
author   : Tom Lane <[email protected]>    
date     : Tue, 1 Sep 2020 13:14:44 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Tue, 1 Sep 2020 13:14:44 -0400    

Historically there's been a hard-wired assumption here that no line of  
a .pgpass file could be as long as NAMEDATALEN*5 bytes.  That's a bit  
shaky to start off with, because (a) there's no reason to suppose that  
host names fit in NAMEDATALEN, and (b) this figure fails to allow for  
backslash escape characters.  However, it fails completely if someone  
wants to use a very long password, and we're now hearing reports of  
people wanting to use "security tokens" that can run up to several  
hundred bytes.  Another angle is that the file is specified to allow  
comment lines, but there's no reason to assume that long comment lines  
aren't possible.  
  
Rather than guessing at what might be a more suitable limit, let's  
replace the fixed-size buffer with an expansible PQExpBuffer.  That  
adds one malloc/free cycle to the typical use-case, but that's surely  
pretty cheap relative to the I/O this code has to do.  
  
Also, add TAP test cases to exercise this code, because there was no  
test coverage before.  
  
This reverts most of commit 2eb3bc588, as there's no longer a need for  
a warning message about overlength .pgpass lines.  (I kept the explicit  
check for comment lines, though.)  
  
In HEAD and v13, this also fixes an oversight in 74a308cf5: there's not  
much point in explicit_bzero'ing the line buffer if we only do so in two  
of the three exit paths.  
  
Back-patch to all supported branches, except that the test case only  
goes back to v10 where src/test/authentication/ was added.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 5394b87a30ce1abd65aee3d2ba339135aa58c920    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 18:33:36 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 18:33:36 -0400    

This follows the American format,  
https://jakubmarian.com/comma-after-i-e-and-e-g/. There is no intention  
of requiring this format for future text, but making existing text  
consistent every few years makes sense.  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : 160c8a4d382204ca2983aba56cc9e5db7167354e    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 17:51:31 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 17:51:31 -0400    

Reported-by: Antonin Houska  
  
Discussion: https://postgr.es/m/21643.1595353537@antos  
  
Backpatch-through: 9.5  

commit   : cda4397f2bc32976f774bf0ec0b3b7d40a77d64e    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 17:36:22 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 17:36:22 -0400    

Also mention files included by postgresql.conf.  
  
Reported-by: Álvaro Herrera  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : 511d51acb33c780f3be018ace68d3f7fb963ea63    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 17:05:53 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 17:05:53 -0400    

It is an int64.  
  
Reported-by: [email protected]  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : e80e7891d35ec94659c3fe8f1d69007d7b05af42    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 16:59:58 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 16:59:58 -0400    

There is an file-fdw example that reads the server config file, so cross  
link them.  
  
Reported-by: Oleg Samoilov  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : 361217659dc80e8f7763eaba047d19391d908f9d    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 16:21:03 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 16:21:03 -0400    

Specifically, explain the v3_ca openssl specification.  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : aa02d352b53329287b22092ed41a9a9ec23b0ef8    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 15:23:18 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 15:23:18 -0400    

For PG, "durable storage" has a clear meaning, while "stable storage"  
does not, so use the former.  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : dd00de928c3fe59f48510f6d02e5e9b8d72c8ae5    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 13:49:17 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 13:49:17 -0400    

It wasn't clear the non-integers are cast to integers for subscripting,  
rather than throwing an error.  
  
Reported-by: [email protected]  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : 4d93773798d68915b3b7d870bdceae9869b62f03    
  
author   : Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 13:43:04 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Mon, 31 Aug 2020 13:43:04 -0400    

Adds constraints and improves wording.  
  
Reported-by: [email protected]  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : fd0f8a6c3a9e30cfd3d1c1ccfb4bb214639b18b4    
  
author   : Magnus Hagander <[email protected]>    
date     : Mon, 31 Aug 2020 13:03:54 +0200    
  
committer: Magnus Hagander <[email protected]>    
date     : Mon, 31 Aug 2020 13:03:54 +0200    

It has always (since the first commit) worked with relative paths, so  
use the same wording as other parts of the documentation.  
  
Author: Bruce Momjian  
Discussion: https://postgr.es/m/CABUevExx-hm=cit+A9LeKBH39srvk8Y2tEZeEAj5mP8YfzNKUg@mail.gmail.com  

commit   : 1ce20826ce80af757658b682c94acb584916e5fe    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 30 Aug 2020 16:03:19 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 30 Aug 2020 16:03:19 -0400    

Back-patch key parts of 4c5cf5431 and 6ca547cf7 into stable branches.  
I didn't touch pg_description entries here, so it's purely a docs  
change; and I didn't fool with any examples either.  The main point  
is so that anyone who's wondering if factorial() exists in the stable  
branches will be reassured.  
  
Mark Dilger and John Naylor, with some adjustments by me  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 0dfec43c829af7e48a159fa5da13f5e48025f985    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 27 Aug 2020 17:36:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 27 Aug 2020 17:36:13 -0400    

collectMatchBitmap() needs to re-find the index tuple it was previously  
looking at, after transiently dropping lock on the index page it's on.  
The tuple should still exist and be at its prior position or somewhere  
to the right of that, since ginvacuum never removes tuples but  
concurrent insertions could add one.  However, there was a thinko in  
that logic, to the effect of expecting any inserted tuples to have the  
same index "attnum" as what we'd been scanning.  Since there's no  
physical separation of tuples with different attnums, it's not terribly  
hard to devise scenarios where this fails, leading to transient "lost  
saved point in index" errors.  (While I've duplicated this with manual  
testing, it seems impossible to make a reproducible test case with our  
available testing technology.)  
  
Fix by just continuing the scan when the attnum doesn't match.  
  
While here, improve the error message used if we do fail, so that it  
matches the wording used in btree for a similar case.  
  
collectMatchBitmap()'s posting-tree code path was previously not  
exercised at all by our regression tests.  While I can't make  
a regression test that exhibits the bug, I can at least improve  
the code coverage here, so do that.  The test case I made for this  
is an extension of one added by 4b754d6c1, so it only works in  
HEAD and v13; didn't seem worth trying hard to back-patch it.  
  
Per bug #16595 from Jesse Kinkead.  This has been broken since  
multicolumn capability was added to GIN (commit 27cb66fdf),  
so back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 6efa6aa96276297a937945feee777d7902a1deb2    
  
author   : Bruce Momjian <[email protected]>    
date     : Tue, 25 Aug 2020 09:53:12 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Tue, 25 Aug 2020 09:53:12 -0400    

They are not "requested" by the server.  
  
Reported-by: Kyotaro Horiguchi  
  
Discussion: https://postgr.es/m/[email protected]  
  
Backpatch-through: 9.5  

commit   : d3701bc8a25bfcc9904e9b11f0a354b1fc0947bd    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 22 Aug 2020 14:46:40 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 22 Aug 2020 14:46:40 -0400    

The trouble with doing this is that an apparently-constant subquery  
output column isn't really constant if it is a grouping column that  
appears in only some of the grouping sets.  A qual using such a  
column would be subject to incorrect const-folding after push-down,  
as seen in bug #16585 from Paul Sivash.  
  
To fix, just disable qual pushdown altogether if the sub-query has  
nonempty groupingSets.  While we could imagine far less restrictive  
solutions, there is not much point in working harder right now,  
because subquery_planner() won't move HAVING clauses to WHERE within  
such a subquery.  If the qual stays in HAVING it's not going to be  
a lot more useful than if we'd kept it at the outer level.  
  
Having said that, this restriction could be removed if we used a  
parsetree representation that distinguished such outputs from actual  
constants, which is something I hope to do in future.  Hence, make  
the patch a minimal addition rather than integrating it more tightly  
(e.g. by renumbering the existing items in subquery_is_pushdown_safe's  
comment).  
  
Back-patch to 9.5 where grouping sets were introduced.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 190fb57c4423f2ef64358f090a828e5fc29a1566    
  
author   : Bruce Momjian <[email protected]>    
date     : Fri, 21 Aug 2020 20:23:09 -0400    
  
committer: Bruce Momjian <[email protected]>    
date     : Fri, 21 Aug 2020 20:23:09 -0400    

This is a redesign of the intro to the managing databases chapter.  
  
Discussion: https://postgr.es/m/[email protected]  
  
Author: David G. Johnston  
  
Backpatch-through: 9.5  

commit   : 37681d7e942e31256efdd9b562a750f1742ac111    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 21 Aug 2020 15:00:43 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 21 Aug 2020 15:00:43 -0400    

If a CREATE TABLE command uses both LIKE and traditional inheritance,  
Vars in CHECK constraints and expression indexes that are absorbed  
from a LIKE parent table tended to get mis-numbered, resulting in  
wrong answers and/or bizarre error messages (though probably not any  
actual crashes, thanks to validation occurring in the executor).  
  
In v12 and up, the same could happen to Vars in GENERATED expressions,  
even in cases with no LIKE clause but multiple traditional-inheritance  
parents.  
  
The cause of the problem for LIKE is that parse_utilcmd.c supposed  
it could renumber such Vars correctly during transformCreateStmt(),  
which it cannot since we have not yet accounted for columns added via  
inheritance.  Fix that by postponing processing of LIKE INCLUDING  
CONSTRAINTS, DEFAULTS, GENERATED, INDEXES till after we've performed  
DefineRelation().  
  
The error with GENERATED and multiple inheritance is a simple oversight  
in MergeAttributes(); it knows it has to renumber Vars in inherited  
CHECK constraints, but forgot to apply the same processing to inherited  
GENERATED expressions (a/k/a defaults).  
  
Per bug #16272 from Tom Gottfried.  The non-GENERATED variants of the  
issue are ancient, presumably dating right back to the addition of  
CREATE TABLE LIKE; hence back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : d4d21490376e3dc863484b97c60cce08096218ce    
  
author   : Alvaro Herrera <[email protected]>    
date     : Mon, 17 Aug 2020 16:20:05 -0400    
  
committer: Alvaro Herrera <[email protected]>    
date     : Mon, 17 Aug 2020 16:20:05 -0400    

This should improve stability in the tests.  
  
Per buildfarm member hyrax (CLOBBER_CACHE_ALWAYS) via Tom Lane.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 722564cf0d7cbcd56b05d8945c360f6e56ba715d    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 17 Aug 2020 15:40:07 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 17 Aug 2020 15:40:07 -0400    

The description of what select_common_type() does was not terribly  
accurate.  Improve it.  
  
David Johnston and Tom Lane  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 5b39f772e2c1670eea2cfde0cc8b08183b010d0e    
  
author   : Michael Paquier <[email protected]>    
date     : Mon, 17 Aug 2020 10:24:42 +0900    
  
committer: Michael Paquier <[email protected]>    
date     : Mon, 17 Aug 2020 10:24:42 +0900    

Since 806a2ae, the work of the bgwriter is split the checkpointer, but a  
portion of the documentation did not get the message.  
  
Author: Masahiko Sawada  
Discussion: https://postgr.es/m/CA+fd4k6jXxjAtjMVC=wG3=QGpauZBtcgN3Jhw+oV7zXGKVLKzQ@mail.gmail.com  
Backpatch-through: 9.5  

commit   : 85aa22cb120d0ee91d41dfa27d307a95f01df89f    
  
author   : Noah Misch <[email protected]>    
date     : Sat, 15 Aug 2020 16:15:59 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Sat, 15 Aug 2020 16:15:59 -0700    

Several PGXN modules reference LockTagType values; renumbering would  
force a recompile of those modules.  Oversight in back-patch of today's  
commit 566372b3d6435639e4cc4476d79b8505a0297c87.  Back-patch to released  
branches, v12 through 9.5.  
  
Reported by Tom Lane.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 5ae01df6f6ef590fd73299050c7112f69c03f3de    
  
author   : Noah Misch <[email protected]>    
date     : Sat, 15 Aug 2020 10:15:53 -0700    
  
committer: Noah Misch <[email protected]>    
date     : Sat, 15 Aug 2020 10:15:53 -0700    

The SimpleLruTruncate() header comment states the new coding rule.  To  
achieve this, add locktype "frozenid" and two LWLocks.  This closes a  
rare opportunity for data loss, which manifested as "apparent  
wraparound" or "could not access status of transaction" errors.  Data  
loss is more likely in pg_multixact, due to released branches' thin  
margin between multiStopLimit and multiWrapLimit.  If a user's physical  
replication primary logged ":  apparent wraparound" messages, the user  
should rebuild standbys of that primary regardless of symptoms.  At less  
risk is a cluster having emitted "not accepting commands" errors or  
"must be vacuumed" warnings at some point.  One can test a cluster for  
this data loss by running VACUUM FREEZE in every database.  Back-patch  
to 9.5 (all supported versions).  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : 7241edc4fa8cda23d04bfe3cd139ed27904eac04    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 14 Aug 2020 22:14:03 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 14 Aug 2020 22:14:03 -0400    

nodeSubplan.c expects that the testexpr for a hashable ANY SubPlan  
has the form of one or more OpExprs whose LHS is an expression of the  
outer query's, while the RHS is an expression over Params representing  
output columns of the subquery.  However, the planner only went as far  
as verifying that the clauses were all binary OpExprs.  This works  
99.99% of the time, because the clauses have the right shape when  
emitted by the parser --- but it's possible for function inlining to  
break that, as reported by PegoraroF10.  To fix, teach the planner  
to check that the LHS and RHS contain the right things, or more  
accurately don't contain the wrong things.  Given that this has been  
broken for years without anyone noticing, it seems sufficient to just  
give up hashing when it happens, rather than go to the trouble of  
commuting the clauses back again (which wouldn't necessarily work  
anyway).  
  
While poking at that, I also noticed that nodeSubplan.c had a baked-in  
assumption that the number of hash clauses is identical to the number  
of subquery output columns.  Again, that's fine as far as parser output  
goes, but it's not hard to break it via function inlining.  There seems  
little reason for that assumption though --- AFAICS, the only thing  
it's buying us is not having to store the number of hash clauses  
explicitly.  Adding code to the planner to reject such cases would take  
more code than getting nodeSubplan.c to cope, so I fixed it that way.  
  
This has been broken for as long as we've had hashable SubPlans,  
so back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/[email protected]  

commit   : b4d8be9f6dc892bd69cf99b587a7d6f925d43ca3    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 14 Aug 2020 13:26:57 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 14 Aug 2020 13:26:57 -0400    

Up to now, upon receipt of a SIGTERM ("smart shutdown" command), the  
postmaster has immediately killed all "optional" background processes,  
and subsequently refused to launch new ones while it's waiting for  
foreground client processes to exit.  No doubt this seemed like an OK  
policy at some point; but it's a pretty bad one now, because it makes  
for a seriously degraded environment for the remaining clients:  
  
* Parallel queries are killed, and new ones fail to launch. (And our  
parallel-query infrastructure utterly fails to deal with the case  
in a reasonable way --- it just hangs waiting for workers that are  
not going to arrive.  There is more work needed in that area IMO.)  
  
* Autovacuum ceases to function.  We can tolerate that for awhile,  
but if bulk-update queries continue to run in the surviving client  
sessions, there's eventually going to be a mess.  In the worst case  
the system could reach a forced shutdown to prevent XID wraparound.  
  
* The bgwriter and walwriter are also stopped immediately, likely  
resulting in performance degradation.  
  
Hence, let's rearrange things so that the only immediate change in  
behavior is refusing to let in new normal connections.  Once the last  
normal connection is gone, shut everything down as though we'd received  
a "fast" shutdown.  To implement this, remove the PM_WAIT_BACKUP and  
PM_WAIT_READONLY states, instead staying in PM_RUN or PM_HOT_STANDBY  
while normal connections remain.  A subsidiary state variable tracks  
whether or not we're letting in new connections in those states.  
  
This also allows having just one copy of the logic for killing child  
processes in smart and fast shutdown modes.  I moved that logic into  
PostmasterStateMachine() by inventing a new state PM_STOP_BACKENDS.  
  
Back-patch to 9.6 where parallel query was added.  In principle  
this'd be a good idea in 9.5 as well, but the risk/reward ratio  
is not as good there, since lack of autovacuum is not a problem  
during typical uses of smart shutdown.  
  
Per report from Bharath Rupireddy.  
  
Patch by me, reviewed by Thomas Munro  
  
Discussion: https://postgr.es/m/CALj2ACXAZ5vKxT9P7P89D87i3MDO9bfS+_bjMHgnWJs8uwUOOw@mail.gmail.com  

commit   : e5902117dd83a330caf68ec2a479c4410cef5518    
  
author   : Alvaro Herrera <[email protected]>    
date     : Thu, 13 Aug 2020 17:33:49 -0400    
  
committer: Alvaro Herrera <[email protected]>    
date     : Thu, 13 Aug 2020 17:33:49 -0400    

When a table is scanned by heapam_index_build_range_scan (née  
IndexBuildHeapScan) and the table lock being held allows concurrent data  
changes, it is possible for new HOT chains to sprout in a page that were  
unknown when the scan of a page happened.  This leads to an error such  
as  
  ERROR:  failed to find parent tuple for heap-only tuple at (X,Y) in table "tbl"  
because the root tuple was not present when we first obtained the list  
of the page's root tuples.  This can be fixed by re-obtaining the list  
of root tuples, if we see that a heap-only tuple appears to point to a  
non-existing root.  
  
This was reported by Anastasia as occurring for BRIN summarization  
(which exists since 9.5), but I think it could theoretically also happen  
with CREATE INDEX CONCURRENTLY (much older) or REINDEX CONCURRENTLY  
(very recent).  It seems a happy coincidence that BRIN forces us to  
backpatch this all the way to 9.5.  
  
Reported-by: Anastasia Lubennikova <[email protected]>  
Diagnosed-by: Anastasia Lubennikova <[email protected]>  
Co-authored-by: Anastasia Lubennikova <[email protected]>  
Co-authored-by: Álvaro Herrera <[email protected]>  
Discussion: https://postgr.es/m/[email protected]  
Backpatch: 9.5 - master  

commit   : 7a3c261fbbb427ffa2ee9223728e811556284a6e    
  
author   : Alvaro Herrera <[email protected]>    
date     : Wed, 12 Aug 2020 15:33:36 -0400    
  
committer: Alvaro Herrera <[email protected]>    
date     : Wed, 12 Aug 2020 15:33:36 -0400    

If a page range is desummarized at just the right time concurrently with  
an index walk, BRIN would raise an error indicating index corruption.  
This is scary and unhelpful; silently returning that the page range is  
not summarized is sufficient reaction.  
  
This bug was introduced by commit 975ad4e602ff as additional protection  
against a bug whose actual fix was elsewhere.  Backpatch equally.  
  
Reported-By: Anastasia Lubennikova <[email protected]>  
Diagnosed-By: Alexander Lakhin <[email protected]>  
Discussion: https://postgr.es/m/[email protected]  
Backpatch: 9.5 - master