Commit Graph

48242 Commits

Author SHA1 Message Date
Tom Lane fc37c6f610 Make new authentication test case more robust.
I happened to notice that the new test case I added in b55b4dad9
falls over if one runs "make check" repeatedly; though not in branches
after v10.  That's because it was assuming that tmp_check/pgpass
wouldn't exist already.  However, it's only been since v11 that the
Makefiles forcibly remove all of tmp_check/ before starting a TAP run.
This fix to unlink the file is therefore strictly necessary only in
v10 ... but it seems wisest to do it across the board, rather than
let the test rely on external logic to get the conditions right.
2020-09-04 21:01:59 -04:00
Tom Lane 9b47ee6e7c Fix over-eager ping'ing in logical replication receiver.
Commit 3f60f690f only partially fixed the broken-status-tracking
issue in LogicalRepApplyLoop: we need ping_sent to have the same
lifetime as last_recv_timestamp.  The effects are much less serious
than what that commit fixed, though.  AFAICS this would just lead to
extra ping requests being sent, once per second until the sender
responds.  Still, it's a bug, so backpatch to v10 as before.

Discussion: https://postgr.es/m/959627.1599248476@sss.pgh.pa.us
2020-09-04 20:20:05 -04:00
Andrew Dunstan 616110eac3 Collect attribute data on extension owned tables being dumped
If this data is not collected, pg_dump segfaults if asked for column
inserts.

Fix by Fabrízio de Royes Mello

Backpatch to release 12 where the bug was introduced.
2020-09-04 13:55:03 -04:00
Bruce Momjian 56f42cf906 C comment: correct use of 64-"byte" cache line size
Reported-by: Kelly Min

Discussion: https://postgr.es/m/CAPSbxatOiQO90LYpSC3+svAU9-sHgDfEP4oFhcEUt_X=DqFA9g@mail.gmail.com

Backpatch-through: 9.5
2020-09-04 13:27:52 -04:00
Tom Lane aa4eeb38f3 Fix rare deadlock failure in create_am regression test.
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/839004.1599185607@sss.pgh.pa.us
2020-09-04 12:40:28 -04:00
Tom Lane 82dd373f2c Avoid lockup of a parallel worker when reporting a long error message.
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
2020-09-03 16:52:09 -04:00
Alvaro Herrera fcc4275681
Fix typo in comment
Introduced by 8b08f7d4820f; backpatch to 11.

Discussion: https://postgr.es/m/20200812214918.GA30353@alvherre.pgsql
2020-09-01 20:43:23 -04:00
Bruce Momjian e3646325f4 doc: clarify that max_wal_size is "during" checkpoints
Previous wording was "between".

Reported-by: Pavel Luzanov

Discussion: https://postgr.es/m/26906a54-d7cb-2f8e-eed7-e31660024694@postgrespro.ru

Backpatch-through: 9.5
2020-09-01 17:00:10 -04:00
Alvaro Herrera 7067ba1b4b
Raise error on concurrent drop of partitioned index
We were already raising an error for DROP INDEX CONCURRENTLY on a
partitioned table, albeit a different and confusing one:
  ERROR:  DROP INDEX CONCURRENTLY must be first action in transaction

Change that to throw a more comprehensible error:
  ERROR:  cannot drop partitioned index \"%s\" concurrently

Michael Paquier authored the test case for indexes on temporary
partitioned tables.

Backpatch to 11, where indexes on partitioned tables were added.

Reported-by: Jan Mussler <jan.mussler@zalando.de>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/16594-d2956ca909585067@postgresql.org
2020-09-01 13:40:43 -04:00
Tom Lane 55aea0c706 Teach libpq to handle arbitrary-length lines in .pgpass files.
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/4187382.1598909041@sss.pgh.pa.us
2020-09-01 13:14:44 -04:00
Bruce Momjian 3fb67ac9c6 doc: add commas after 'i.e.' and 'e.g.'
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/20200825183619.GA22369@momjian.us

Backpatch-through: 9.5
2020-08-31 18:33:37 -04:00
Bruce Momjian b1f52817bc C comment: remove mention of use of t_hoff WAL structure member
Reported-by: Antonin Houska

Discussion: https://postgr.es/m/21643.1595353537@antos

Backpatch-through: 9.5
2020-08-31 17:51:31 -04:00
Bruce Momjian 9774d9c777 pg_upgrade doc: mention saving postgresql.conf.auto files
Also mention files included by postgresql.conf.

Reported-by: Álvaro Herrera

Discussion: https://postgr.es/m/08AD4526-75AB-457B-B2DD-099663F28040@yesql.se

Backpatch-through: 9.5
2020-08-31 17:36:22 -04:00
Bruce Momjian 2bf1bec585 docs: in mapping SQL to C data types, timestamp isn't a pointer
It is an int64.

Reported-by: ajulien@shaktiware.fr

Discussion: https://postgr.es/m/159845038271.24995.15682121015698255155@wrigleys.postgresql.org

Backpatch-through: 9.5
2020-08-31 17:05:53 -04:00
Bruce Momjian 02fb7eef91 doc: cross-link file-fdw and CSV config log sections
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/159800192078.2886.10431506404995508950@wrigleys.postgresql.org

Backpatch-through: 9.5
2020-08-31 16:59:58 -04:00
Bruce Momjian 01bcfe705d docs: clarify intermediate certificate creation instructions
Specifically, explain the v3_ca openssl specification.

Discussion: https://postgr.es/m/20200824175653.GA32411@momjian.us

Backpatch-through: 9.5
2020-08-31 16:21:03 -04:00
Bruce Momjian 0d447ba962 docs: replace "stable storage" with "durable" in descriptions
For PG, "durable storage" has a clear meaning, while "stable storage"
does not, so use the former.

Discussion: https://postgr.es/m/20200817165222.GA31806@momjian.us

Backpatch-through: 9.5
2020-08-31 15:23:19 -04:00
Bruce Momjian 2f8ea9116b doc: improve description of subscripting of arrays
It wasn't clear the non-integers are cast to integers for subscripting,
rather than throwing an error.

Reported-by: sean@materialize.io

Discussion: https://postgr.es/m/159538675800.624.7728794628229799531@wrigleys.postgresql.org

Backpatch-through: 9.5
2020-08-31 13:49:17 -04:00
Bruce Momjian ac736e43aa docs: improve 'capitals' inheritance example
Adds constraints and improves wording.

Reported-by: 2552891@gmail.com

Discussion: https://postgr.es/m/159586122762.680.1361378513036616007@wrigleys.postgresql.org

Backpatch-through: 9.5
2020-08-31 13:43:04 -04:00
Bruce Momjian 5277f493dd doc: clarify the useful features of procedures
This was not clearly documented when procedures were added in PG 11.

Reported-by: Robin Abbi

Discussion: https://postgr.es/m/CAGmg_NX327KKVuJmbWZD=pGutYFxzZjX1rU+3ji8UuX=8ONn9Q@mail.gmail.com

Backpatch-through: 11
2020-08-31 13:20:04 -04:00
Magnus Hagander 73952310bf Fix docs bug stating file_fdw requires absolute paths
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
2020-08-31 13:05:57 +02:00
Tom Lane 9dee85b5b8 Mark factorial operator, and postfix operators in general, as deprecated.
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/BE2DF53D-251A-4E26-972F-930E523580E9@enterprisedb.com
2020-08-30 16:03:19 -04:00
Tom Lane ff3c16d1e7 Fix code for re-finding scan position in a multicolumn GIN index.
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/16595-633118be8eef9ce2@postgresql.org
2020-08-27 17:36:13 -04:00
Bruce Momjian fa3bd8d853 docs: client certificates are always sent to the server
They are not "requested" by the server.

Reported-by: Kyotaro Horiguchi

Discussion: https://postgr.es/m/20200825.155320.986648039251743210.horikyota.ntt@gmail.com

Backpatch-through: 9.5
2020-08-25 09:53:12 -04:00
Peter Eisentraut 4534a1e810 doc: Fix up title case
This fixes some instances that were missed in earlier processings and
that now look a bit strange because they are inconsistent with nearby
titles.
2020-08-25 07:31:12 +02:00
Tom Lane 6b701eaaa9 Avoid pushing quals down into sub-queries that have grouping sets.
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/16585-9d8c340d23ade8c1@postgresql.org
2020-08-22 14:46:40 -04:00
Bruce Momjian 2060f0064e docs: improve description of how to handle multiple databases
This is a redesign of the intro to the managing databases chapter.

Discussion: https://postgr.es/m/159586122762.680.1361378513036616007@wrigleys.postgresql.org

Author: David G. Johnston

Backpatch-through: 9.5
2020-08-21 20:23:09 -04:00
Bruce Momjian 90f6435f67 docs: add COMMENT examples for new features, rename rtree
Reported-by: Jürgen Purtz

Discussion: https://postgr.es/m/15ec5428-d46a-1725-f38d-44986a977abb@purtz.de

Author: Jürgen Purtz

Backpatch-through: 11
2020-08-21 18:29:37 -04:00
Tom Lane d9253df12e Fix handling of CREATE TABLE LIKE with inheritance.
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/16272-6e32da020e9a9381@postgresql.org
2020-08-21 15:00:43 -04:00
David Rowley 3248633579 Fix a few typos in JIT comments and README
Reviewed-by: Abhijit Menon-Sen
Reviewed-by: Andres Freund
Discussion: https://postgr.es/m/CAApHDvobgmCs6CohqhKTUf7D8vffoZXQTCBTERo9gbOeZmvLTw%40mail.gmail.com
Backpatch-through: 11, where JIT was added
2020-08-21 09:35:24 +12:00
Alvaro Herrera da9ec328dd
Revise REINDEX CONCURRENTLY recovery instructions
When the leftover invalid index is "ccold", there's no need to re-run
the command.  Reword the instructions to make that explicit.

Backpatch to 12, where REINDEX CONCURRENTLY appeared.

Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://postgr.es/m/20200819211312.GA15497@alvherre.pgsql
2020-08-20 13:49:04 -04:00
Tom Lane 814a57065e Suppress unnecessary RelabelType nodes in yet more cases.
Commit a477bfc1d fixed eval_const_expressions() to ensure that it
didn't generate unnecessary RelabelType nodes, but I failed to notice
that some other places in the planner had the same issue.  Really
noplace in the planner should be using plain makeRelabelType(), for
fear of generating expressions that should be equal() to semantically
equivalent trees, but aren't.

An example is that because canonicalize_ec_expression() failed
to be careful about this, we could end up with an equivalence class
containing both a plain Const, and a Const-with-RelabelType
representing exactly the same value.  So far as I can tell this led to
no visible misbehavior, but we did waste a bunch of cycles generating
and evaluating "Const = Const-with-RelabelType" to prove such entries
are redundant.

Hence, move the support function added by a477bfc1d to where it can
be more generally useful, and use it in the places where planner code
previously used makeRelabelType.

Back-patch to v12, like the previous patch.  While I have no concrete
evidence of any real misbehavior here, it's certainly possible that
I overlooked a case where equivalent expressions that aren't equal()
could cause a user-visible problem.  In any case carrying extra
RelabelType nodes through planning to execution isn't very desirable.

Discussion: https://postgr.es/m/1311836.1597781384@sss.pgh.pa.us
2020-08-19 14:07:49 -04:00
Heikki Linnakangas aecefffc3f Avoid non-constant format string argument to fprintf().
As Tom Lane pointed out, it could defeat the compiler's printf() format
string verification.

Backpatch to v12, like that patch that introduced it.

Discussion: https://www.postgresql.org/message-id/1069283.1597672779%40sss.pgh.pa.us
2020-08-18 13:13:28 +03:00
Alvaro Herrera 4f47c8e7d4
Disable autovacuum for BRIN test table
This should improve stability in the tests.

Per buildfarm member hyrax (CLOBBER_CACHE_ALWAYS) via Tom Lane.

Discussion: https://postgr.es/m/871534.1597503261@sss.pgh.pa.us
2020-08-17 16:20:06 -04:00
Tom Lane 314f65716c Doc: fix description of UNION/CASE/etc type unification.
The description of what select_common_type() does was not terribly
accurate.  Improve it.

David Johnston and Tom Lane

Discussion: https://postgr.es/m/1019930.1597613200@sss.pgh.pa.us
2020-08-17 15:40:07 -04:00
Heikki Linnakangas 9f44d71b06 Fix printing last progress report line in client programs.
A number of client programs have a "--progress" option that when printing
to a TTY, updates the current line by printing a '\r' and overwriting it.
After the last line, '\n' needs to be printed to move the cursor to the
next line. pg_basebackup and pgbench got this right, but pg_rewind and
pg_checksums were slightly wrong. pg_rewind printed the newline to stdout
instead of stderr, and pg_checksums printed the newline even when not
printing to a TTY. Fix them, and also add a 'finished' argument to
pg_basebackup's progress_report() function, to keep it consistent with
the other programs.

Backpatch to v12. pg_rewind's newline was broken with the logging changes
in commit cc8d415117 in v12, and pg_checksums was introduced in v12.

Discussion: https://www.postgresql.org/message-id/82b539e5-ae33-34b0-1aee-22b3379fd3eb@iki.fi
2020-08-17 09:33:10 +03:00
Michael Paquier 29bd2cbe36 doc: Fix description about bgwriter and checkpoint in HA section
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
2020-08-17 10:24:31 +09:00
Noah Misch 06e50d8f7e Move new LOCKTAG_DATABASE_FROZEN_IDS to end of enum LockTagType.
Several PGXN modules reference LockTagType values; renumbering would
force a recompile of those modules.  Oversight in back-patch of today's
commit 566372b3d6.  Back-patch to released
branches, v12 through 9.5.

Reported by Tom Lane.

Discussion: https://postgr.es/m/921383.1597523945@sss.pgh.pa.us
2020-08-15 16:15:59 -07:00
Noah Misch 30e68a2abb Prevent concurrent SimpleLruTruncate() for any given SLRU.
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/20190218073103.GA1434723@rfd.leadboat.com
2020-08-15 10:15:56 -07:00
Tom Lane 912fb290c5 Be more careful about the shape of hashable subplan clauses.
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/1549209182255-0.post@n3.nabble.com
2020-08-14 22:14:03 -04:00
Alvaro Herrera 3dadcb2b31
pg_dump: fix dependencies on FKs to partitioned tables
Parallel-restoring a foreign key that references a partitioned table
with several levels of partitions can fail:

pg_restore: while PROCESSING TOC:
pg_restore: from TOC entry 6684; 2606 29166 FK CONSTRAINT fk fk_a_fkey postgres
pg_restore: error: could not execute query: ERROR:  there is no unique constraint matching given keys for referenced table "pk"
Command was: ALTER TABLE fkpart3.fk
    ADD CONSTRAINT fk_a_fkey FOREIGN KEY (a) REFERENCES fkpart3.pk(a);

This happens in parallel restore mode because some index partitions
aren't yet attached to the topmost partitioned index that the FK uses,
and so the index is still invalid.  The current code marks the FK as
dependent on the first level of index-attach dump objects; the bug is
fixed by recursively marking the FK on their children.

Backpatch to 12, where FKs to partitioned tables were introduced.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/3170626.1594842723@sss.pgh.pa.us
Backpatch: 12-master
2020-08-14 17:33:31 -04:00
Tom Lane 42566a2500 Fix postmaster's behavior during smart shutdown.
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
2020-08-14 13:26:57 -04:00
Heikki Linnakangas f81167adbf Fix typo in test comment. 2020-08-14 10:41:19 +03:00
Alvaro Herrera 1122a903e9
Handle new HOT chains in index-build table scans
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 <a.lubennikova@postgrespro.ru>
Diagnosed-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Co-authored-by: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/602d8487-f0b2-5486-0088-0f372b2549fa@postgrespro.ru
Backpatch: 9.5 - master
2020-08-13 17:33:49 -04:00
Alvaro Herrera 0426c75e7d
BRIN: Handle concurrent desummarization properly
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 975ad4e602 as additional protection
against a bug whose actual fix was elsewhere.  Backpatch equally.

Reported-By: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>
Diagnosed-By: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/2588667e-d07d-7e10-74e2-7e1e46194491@postgrespro.ru
Backpatch: 9.5 - master
2020-08-12 15:33:36 -04:00
Tom Lane 0ad348f38e Stamp 12.4. 2020-08-10 17:15:53 -04:00
Tom Lane f9ddc36ed6 Last-minute updates for release notes.
Security: CVE-2020-14349, CVE-2020-14350
2020-08-10 15:35:46 -04:00
Noah Misch 515ee4a7e5 Document clashes between logical replication and untrusted users.
Back-patch to v10, which introduced logical replication.

Security: CVE-2020-14349
2020-08-10 09:22:58 -07:00
Noah Misch 64a71062e0 Empty search_path in logical replication apply worker and walsender.
This is like CVE-2018-1058 commit
582edc369c.  Today, a malicious user of a
publisher or subscriber database can invoke arbitrary SQL functions
under an identity running replication, often a superuser.  This fix may
cause "does not exist" or "no schema has been selected to create in"
errors in a replication process.  After upgrading, consider watching
server logs for these errors.  Objects accruing schema qualification in
the wake of the earlier commit are unlikely to need further correction.
Back-patch to v10, which introduced logical replication.

Security: CVE-2020-14349
2020-08-10 09:22:58 -07:00
Noah Misch d4d0ec9e79 Move connect.h from fe_utils to src/include/common.
Any libpq client can use the header.  Clients include backend components
postgres_fdw, dblink, and logical replication apply worker.  Back-patch
to v10, because another fix needs this.  In released branches, just copy
the header and keep the original.
2020-08-10 09:22:58 -07:00