Commit Graph

23126 Commits

Author SHA1 Message Date
Alvaro Herrera 83011ce7d7
Rework grammar for REINDEX
The part of grammar have grown needlessly duplicative and more complex
that necessary.  Rewrite.

Reviewed-by: Michaël Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20220721174212.cmitjpuimx6ssyyj@alvherre.pgsql
2022-07-22 19:23:39 +02:00
Tom Lane 0b292bed92 Close old gap in dependency checks for functions returning composite.
The dependency logic failed to register a column-level dependency
when a view or rule contains a reference to a specific column of
the result of a function-returning-composite.  That meant you could
drop the column from the composite type, causing trouble for future
executions of the view.  We've known about this for years, but never
summoned the energy to actually fix it, instead installing various
low-level defenses to prevent crashing on references to dropped columns.
We had to do that to plug the hole in stable branches, where there might
be pre-existing broken references; but let's fix the root cause today.

To do that, add some logic (borrowed from get_rte_attribute_is_dropped)
to find_expr_references_walker, to check whether a Var referencing an
RTE_FUNCTION RTE is referencing a column of a composite type, and if
so add the proper dependency.

However ... it seems mighty unwise to remove said low-level defenses,
since there could be other bugs now or in the future that allow
reaching them.  By the same token, letting those defenses go untested
seems unwise.  Hence, rather than just dropping the associated test
cases, hack them to continue working by the expedient of manually
dropping the pg_depend entries that this fix installs.

Back-patch into v15.  I don't want to risk changing this behavior
in stable branches, but it seems not too late for v15.  (Since
we have already forced initdb for beta3, we can be sure that all
production v15 installations will have these added dependencies.)

Discussion: https://postgr.es/m/182492.1658431155@sss.pgh.pa.us
2022-07-22 12:46:42 -04:00
Alvaro Herrera 7d158e8cb4
parser: centralize common auxiliary productions
Things like "opt_name" can well be shared by various commands rather
than there being multiple definitions of the same thing.  Rename these
productions and move them to appear together in gram.y, which may
improve chances of reuse in the future.

Discussion: https://postgr.es/m/20220721174212.cmitjpuimx6ssyyj@alvherre.pgsql
2022-07-22 13:13:20 +02:00
Alvaro Herrera 9853bf6ab0
Update src/backend/parser/README
New files have been added to this directory, but not listed here.
Repair.
2022-07-22 12:56:21 +02:00
Thomas Munro 5344723755 Remove unnecessary Windows-specific basebackup code.
Commit c6f2f016 added an explicit check for a Windows "junction point".
That turned out to be needed only because get_dirent_type() was busted
on Windows.  It's been fixed by commit 9d3444dc, so remove it.

Add a TAP-test to demonstrate that in-place tablespaces are copied by
pg_basebackup.  This exercises the codepath that would fail before
c6f2f016 on Windows, and shows that it still doesn't fail now that we're
using get_dirent_type() on both Windows and Unix.

Back-patch to 15, where in-place tablespaces arrived and caused this
problem (ie directories where previously only symlinks were expected).

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CA%2BhUKGLzLK4PUPx0_AwXEWXOYAejU%3D7XpxnYE55Y%2Be7hB2N3FA%40mail.gmail.com
2022-07-22 17:41:47 +12:00
Thomas Munro a1b56090eb Remove O_FSYNC and associated macros.
O_FSYNC was a pre-POSIX way of spelling O_SYNC, supported since commit
9d645fd84c for non-conforming operating systems of the time.  It's not
needed on any modern system.  We can just use standard O_SYNC directly
if it exists (= all targeted systems except Windows), and get rid of our
OPEN_SYNC_FLAG macro.

Similarly for standard O_DSYNC, we can just use that directly if it
exists (= all targeted systems except DragonFlyBSD), and get rid of our
OPEN_DATASYNC_FLAG macro.

We still avoid choosing open_datasync as a default value for
wal_sync_method if O_DSYNC has the same value as O_SYNC (= only
OpenBSD), so there is no change in default behavior.

Discussion: https://postgr.es/m/CA%2BhUKGJE7y92NY7FG2ftUbZUaqohBU65_Ys_7xF5mUHo4wirTQ%40mail.gmail.com
2022-07-22 12:41:17 +12:00
Thomas Munro 4f1f5a7f85 Remove fls(), use pg_leftmost_one_pos32() instead.
Commit 4f658dc8 provided the traditional BSD fls() function in
src/port/fls.c so it could be used in several places.  Later we added a
bunch of similar facilities in pg_bitutils.h, based on compiler
builtins that map to hardware instructions.  It's a bit confusing to
have both 1-based and 0-based variants of this operation in use in
different parts of the tree, and neither is blessed by a standard.
Let's drop fls.c and the configure probe, and reuse the newer code.

Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKG%2B7dSX1XF8yFGmYk-%3D48dbjH2kmzZj16XvhbrWP-9BzRg%40mail.gmail.com
2022-07-22 10:41:50 +12:00
Dean Rasheed 624aa2a13b Make the name optional in CREATE STATISTICS.
This allows users to omit the statistics name in a CREATE STATISTICS
command, letting the system auto-generate a sensible, unique name,
putting the statistics object in the same schema as the table.

Simon Riggs, reviewed by Matthias van de Meent.

Discussion: https://postgr.es/m/CANbhV-FGD2d_C3zFTfT2aRfX_TaPSgOeKES58RLZx5XzQp5NhA@mail.gmail.com
2022-07-21 19:23:13 +01:00
Tom Lane b9654cecea Fix ruleutils issues with dropped cols in functions-returning-composite.
Due to lack of concern for the case in the dependency code, it's
possible to drop a column of a composite type even though stored
queries have references to the dropped column via functions-in-FROM
that return the composite type.  There are "soft" references,
namely FROM-clause aliases for such columns, and "hard" references,
that is actual Vars referring to them.  The right fix for hard
references is to add dependencies preventing the drop; something
we've known for many years and not done (and this commit still doesn't
address it).  A "soft" reference shouldn't prevent a drop though.
We've been around on this before (cf. 9b35ddce9, 2c4debbd0), but
nobody had noticed that the current behavior can result in dump/reload
failures, because ruleutils.c can print more column aliases than the
underlying composite type now has.  So we need to rejigger the
column-alias-handling code to treat such columns as dropped and not
print aliases for them.

Rather than writing new code for this, I used expandRTE() which already
knows how to figure out which function result columns are dropped.
I'd initially thought maybe we could use expandRTE() in all cases, but
that fails for EXPLAIN's purposes, because the planner strips a lot of
RTE infrastructure that expandRTE() needs.  So this patch just uses it
for unplanned function RTEs and otherwise does things the old way.

If there is a hard reference (Var), then removing the column alias
causes us to fail to print the Var, since there's no longer a name
to print.  Failing seems less desirable than printing a made-up
name, so I made it print "?dropped?column?" instead.

Per report from Timo Stolz.  Back-patch to all supported branches.

Discussion: https://postgr.es/m/5c91267e-3b6d-5795-189c-d15a55d61dbb@nullachtvierzehn.de
2022-07-21 13:56:02 -04:00
Amit Kapila 366283961a Allow users to skip logical replication of data having origin.
This patch adds a new SUBSCRIPTION parameter "origin". It specifies
whether the subscription will request the publisher to only send changes
that don't have an origin or send changes regardless of origin. Setting it
to "none" means that the subscription will request the publisher to only
send changes that have no origin associated. Setting it to "any" means
that the publisher sends changes regardless of their origin. The default
is "any".
Usage:
CREATE SUBSCRIPTION sub1 CONNECTION 'dbname=postgres port=9999'
PUBLICATION pub1 WITH (origin = none);

This can be used to avoid loops (infinite replication of the same data)
among replication nodes.

This feature allows filtering only the replication data originating from
WAL but for initial sync (initial copy of table data) we don't have such a
facility as we can only distinguish the data based on origin from WAL. As
a follow-up patch, we are planning to forbid the initial sync if the
origin is specified as none and we notice that the publication tables were
also replicated from other publishers to avoid duplicate data or loops.

We forbid to allow creating origin with names 'none' and 'any' to avoid
confusion with the same name options.

Author: Vignesh C, Amit Kapila
Reviewed-By: Peter Smith, Amit Kapila, Dilip Kumar, Shi yu, Ashutosh Bapat, Hayato Kuroda
Discussion: https://postgr.es/m/CALDaNm0gwjY_4HFxvvty01BOT01q_fJLKQ3pWP9=9orqubhjcQ@mail.gmail.com
2022-07-21 08:47:38 +05:30
Tom Lane af119e08fd Dump more fields when dumping planner internal data structures.
Commit 964d01ae9 marked a lot of fields as read_write_ignore
to stay consistent with what was dumped by the manually-maintained
outfuncs.c code.  However, it seems that a pretty fair number
of those omissions were either flat-out oversights, or a shortcut
taken because hand-written code seemed like it'd be too much trouble.
Let's upgrade things where it seems to make sense to dump.

To do this, we need to add support to gen_node_support.pl and
outfuncs.c for variable-length arrays of Node pointers.  That's
pretty straightforward given the model of the existing code
for arrays of scalars, but I found I needed to tighten the
type-recognizing regexes in gen_node_support.pl.  (As they
stood, they mistook "foo **" for "foo *".  Make sure they're
all fully anchored to prevent additional problems.)

The main thing left un-done here is that a lot of partitioning-related
structs are still not dumped, because they are bare structs not Nodes.
I'm not sure about the wisdom of that choice ... but changing it would
be fairly invasive, so it probably requires more justification than
just making planner node dumps more complete.

Discussion: https://postgr.es/m/1295668.1658258637@sss.pgh.pa.us
2022-07-20 13:54:30 -04:00
Jeff Davis 6c31ac091f Process shared_preload_libraries in single-user mode.
Without processing shared_preload_libraries, it's impossible to
recover if custom WAL resource managers are needed. It may also pose a
problem running VACUUM on a table with a custom AM, if the module
implementing the AM is expecting to be loaded by
shared_preload_libraries.

The reason this wasn't done before was just the general principle to
do fewer things in single-user mode. But it's easy enough to just set
shared_preload_libraries to empty, for the same effect.

Discussion: https://postgr.es/m/9decc18a42634f8a2f15c97a385a0f51a752f396.camel%40j-davis.com
Reviewed-by: Tom Lane, Andres Freund
Backpatch-through: 15
2022-07-20 10:15:47 -07:00
Tom Lane 2d04277121 Make serialization of Nodes' scalar-array fields more robust.
When the ability to print variable-length-array fields was first
added to outfuncs.c, there was no corresponding read capability,
as it was used only for debug dumps of planner-internal Nodes.
Not a lot of thought seems to have been put into the output format:
it's just the space-separated array elements and nothing else.
Later such fields appeared in Plan nodes, and still later we grew
read support so that Plans could be transferred to parallel workers,
but the original text format wasn't rethought.  It seems inadequate
to me because (a) no cross-check is possible that we got the right
number of array entries, (b) we can't tell the difference between
a NULL pointer and a zero-length array, and (c) except for
WRITE_INDEX_ARRAY, we'd crash if a non-zero length is specified
when the pointer is NULL, a situation that can arise in some fields
that we currently conveniently avoid printing.

Since we're currently in a campaign to make the Node infrastructure
generally more it-just-works-without-thinking-about-it, now seems
like a good time to improve this.

Let's adopt a format similar to that used for Lists, that is "<>"
for a NULL pointer or "(item item item)" otherwise.  Also retool
the code to not have so many copies of the identical logic.

I bumped catversion out of an abundance of caution, although I think
that we don't use any such array fields in Nodes that can get into
the catalogs.

Discussion: https://postgr.es/m/1528424.1658272135@sss.pgh.pa.us
2022-07-20 13:04:33 -04:00
Dean Rasheed bcedd8f5fc Make subquery aliases optional in the FROM clause.
This allows aliases for sub-SELECTs and VALUES clauses in the FROM
clause to be omitted.

This is an extension of the SQL standard, supported by some other
database systems, and so eases the transition from such systems, as
well as removing the minor inconvenience caused by requiring these
aliases.

Patch by me, reviewed by Tom Lane.

Discussion: https://postgr.es/m/CAEZATCUCGCf82=hxd9N5n6xGHPyYpQnxW8HneeH+uP7yNALkWA@mail.gmail.com
2022-07-20 09:29:42 +01:00
Fujii Masao b24b2be119 Fix assertion failure and segmentation fault in backup code.
When a non-exclusive backup is canceled, do_pg_abort_backup() is called
and resets some variables set by pg_backup_start (pg_start_backup in v14
or before). But previously it forgot to reset the session state indicating
whether a non-exclusive backup is in progress or not in this session.

This issue could cause an assertion failure when the session running
BASE_BACKUP is terminated after it executed pg_backup_start and
pg_backup_stop (pg_stop_backup in v14 or before). Also it could cause
a segmentation fault when pg_backup_stop is called after BASE_BACKUP
in the same session is canceled.

This commit fixes the issue by making do_pg_abort_backup reset
that session state.

Back-patch to all supported branches.

Author: Fujii Masao
Reviewed-by: Kyotaro Horiguchi, Masahiko Sawada, Michael Paquier, Robert Haas
Discussion: https://postgr.es/m/3374718f-9fbf-a950-6d66-d973e027f44c@oss.nttdata.com
2022-07-20 09:57:01 +09:00
Fujii Masao ee79647769 Prevent BASE_BACKUP in the middle of another backup in the same session.
Multiple non-exclusive backups are able to be run conrrently in different
sessions. But, in the same session, only one non-exclusive backup can be
run at the same moment. If pg_backup_start (pg_start_backup in v14 or before)
is called in the middle of another non-exclusive backup in the same session,
an error is thrown.

However, previously, in logical replication walsender mode, even if that
walsender session had already called pg_backup_start and started
a non-exclusive backup, it could execute BASE_BACKUP command and
start another non-exclusive backup. Which caused subsequent pg_backup_stop
to throw an error because BASE_BACKUP unexpectedly reset the session state
marked by pg_backup_start.

This commit prevents BASE_BACKUP command in the middle of another
non-exclusive backup in the same session.

Back-patch to all supported branches.

Author: Fujii Masao
Reviewed-by: Kyotaro Horiguchi, Masahiko Sawada, Michael Paquier, Robert Haas
Discussion: https://postgr.es/m/3374718f-9fbf-a950-6d66-d973e027f44c@oss.nttdata.com
2022-07-20 09:56:42 +09:00
Michael Paquier 12c254c99f Tweak detail and hint messages to be consistent with project policy
Detail and hint messages should be full sentences and should end with a
period, but some of the messages newly-introduced in v15 did not follow
that.

Author: Justin Pryzby
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/20220719120948.GF12702@telsasoft.com
Backpatch-through: 15
2022-07-20 09:50:12 +09:00
Tom Lane 13d8388151 Fix missed corner cases for grantable permissions on GUCs.
We allow users to set the values of not-yet-loaded extension GUCs,
remembering those values in "placeholder" GUC entries.  When/if
the extension is loaded later in the session, we need to verify that
the user had permissions to set the GUC.  That was done correctly
before commit a0ffa885e, but as of that commit, we'd check the
permissions of the active role when the LOAD happens, not the role
that had set the value.  (This'd be a security bug if it had made it
into a released version.)

In principle this is simple enough to fix: we just need to remember
the exact role OID that set each GUC value, and use that not
GetUserID() when verifying permissions.  Maintaining that data in
the guc.c data structures is slightly tedious, but fortunately it's
all basically just copy-n-paste of the logic for tracking the
GucSource of each setting, as we were already doing.

Another oversight is that validate_option_array_item() hadn't
been taught to check for granted GUC privileges.  This appears
to manifest only in that ALTER ROLE/DATABASE RESET ALL will
fail to reset settings that the user should be allowed to reset.

Patch by myself and Nathan Bossart, per report from Nathan Bossart.
Back-patch to v15 where the faulty code came in.

Discussion: https://postgr.es/m/20220706224727.GA2158260@nathanxps13
2022-07-19 17:21:55 -04:00
Tom Lane d6a3aeb9a3 Convert planner's AggInfo and AggTransInfo structs to proper Nodes.
This is mostly just to get outfuncs.c support for them, so that
the agginfos and aggtransinfos lists can be dumped when dumping
the contents of PlannerInfo.

While here, improve some related comments; notably, clean up
obsolete comments left over from when preprocess_minmax_aggregates
had to make its own scan of the query tree.

Discussion: https://postgr.es/m/742479.1658160504@sss.pgh.pa.us
2022-07-19 12:29:37 -04:00
Tom Lane e2f6c307c0 Estimate cost of elided SubqueryScan, Append, MergeAppend nodes better.
setrefs.c contains logic to discard no-op SubqueryScan nodes, that is,
ones that have no qual to check and copy the input targetlist unchanged.
(Formally it's not very nice to be applying such optimizations so late
in the planner, but there are practical reasons for it; mostly that we
can't unify relids between the subquery and the parent query until we
flatten the rangetable during setrefs.c.)  This behavior falsifies our
previous cost estimates, since we would've charged cpu_tuple_cost per
row just to pass data through the node.  Most of the time that's little
enough to not matter, but there are cases where this effect visibly
changes the plan compared to what you would've gotten with no
sub-select.

To improve the situation, make the callers of cost_subqueryscan tell
it whether they think the targetlist is trivial.  cost_subqueryscan
already has the qual list, so it can check the other half of the
condition easily.  It could make its own determination of tlist
triviality too, but doing so would be repetitive (for callers that
may call it several times) or unnecessarily expensive (for callers
that can determine this more cheaply than a general test would do).

This isn't a 100% solution, because createplan.c also does things
that can falsify any earlier estimate of whether the tlist is
trivial.  However, it fixes nearly all cases in practice, if results
for the regression tests are anything to go by.

setrefs.c also contains logic to discard no-op Append and MergeAppend
nodes.  We did have knowledge of that behavior at costing time, but
somebody failed to update it when a check on parallel-awareness was
added to the setrefs.c logic.  Fix that while we're here.

These changes result in two minor changes in query plans shown in
our regression tests.  Neither is relevant to the purposes of its
test case AFAICT.

Patch by me; thanks to Richard Guo for review.

Discussion: https://postgr.es/m/2581077.1651703520@sss.pgh.pa.us
2022-07-19 11:18:19 -04:00
Alvaro Herrera 1679d57a55
Wrap overly long lines
Reported by Richard Guo.

Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAMbWs4-3ywL_tPHJKk-Vvzr-tBaR--b6XxGGm8Xe7vsG38AWog@mail.gmail.com
2022-07-19 09:54:03 +02:00
Peter Eisentraut 4371d34f29 Clean up temp file from refactored dtrace rule
related to eb6569fd0e
2022-07-19 07:31:58 +02:00
Michael Paquier 2cbc3c17a5 Rework logic and simplify syntax of REINDEX DATABASE/SYSTEM
Per discussion, this commit includes a couple of changes to these two
flavors of REINDEX:
* The grammar is changed to make the name of the object optional, hence
one can rebuild all the indexes of the wanted area by specifying only
"REINDEX DATABASE;" or "REINDEX SYSTEM;".  Previously, the object name
was mandatory and had to match the name of the database on which the
command is issued.
* REINDEX DATABASE is changed to ignore catalogs, making this task only
possible with REINDEX SYSTEM.  This is a historical change, but there
was no way to work only on the indexes of a database without touching
the catalogs.  We have discussed more approaches here, like the addition
of an option to skip the catalogs without changing the original
behavior, but concluded that what we have here is for the best.

This builds on top of the TAP tests introduced in 5fb5b6c, showing the
change in behavior for REINDEX SYSTEM.  reindexdb is updated so as we do
not issue an extra REINDEX SYSTEM when working on a database in the
non-concurrent case, something that was confusing when --concurrently
got introduced, so this simplifies the code.

Author: Simon Riggs
Reviewed-by: Ashutosh Bapat, Bernd Helmle, Álvaro Herrera, Cary Huang,
Michael Paquier
Discussion: https://postgr.es/m/CANbhV-H=NH6Om4-X6cRjDWfH_Mu1usqwkuYVp-hwdB_PSHWRfg@mail.gmail.com
2022-07-19 11:45:06 +09:00
Andres Freund 950e64fa46 Use STDOUT/STDERR_FILENO in most of syslogger.
This fixes problems on windows when logging collector is used in a service,
failing with:
FATAL:  could not redirect stderr: Bad file descriptor

This is triggered by 76e38b37a5. The problem is that STDOUT/STDERR_FILENO
aren't defined on windows, which lead us to use _fileno(stdout) etc, but that
doesn't work if stdout/stderr are closed.

Author: Andres Freund <andres@anarazel.de>
Reported-By: Sandeep Thakkar <sandeep.thakkar@enterprisedb.com>
Message-Id: 20220520164558.ozb7lm6unakqzezi@alap3.anarazel.de (on pgsql-packagers)
Backpatch: 15-, where 76e38b37a5 came in
2022-07-18 17:22:11 -07:00
Andres Freund eb6569fd0e Refactor dtrace postprocessing make rules
This is in preparation for building postgres with meson / ninja.

Move the dtrace postprocessing sed commands into a separate file so
that it can be shared by meson.  Also split the rule into two for
proper dependency declaration.

Reviewed-by: Andres Freund <andres@anarazel.de>
Author: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/5e216522-ba3c-f0e6-7f97-5276d0270029@enterprisedb.com
2022-07-18 12:33:02 -07:00
Andres Freund adba4b7471 Add output directory option to gen_node_support.pl
This is in preparation for building postgres with meson / ninja.

When building with meson, commands are run at the root of the build tree. Add
an option to put build output into the appropriate place. This can be utilized
by src/tools/msvc/ for a minor simplification, which also provides some
coverage for the new option.

Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/5e216522-ba3c-f0e6-7f97-5276d0270029@enterprisedb.com
2022-07-18 12:32:53 -07:00
Andres Freund 2bf626b714 Add output file argument to generate-errcodes.pl
This is in preparation for building postgres with meson / ninja.

meson's 'capture' (redirecting stdout to a file) is a bit slower than programs
redirecting output themselves (mostly due to a python wrapper necessary for
windows). That doesn't matter for most things, but errcodes.h is a dependency
of nearly everything, making it a bit faster seem worthwhile.

Medium term it might also be worth avoiding writing errcodes.h if its contents
didn't actually change, to avoid unnecessary recompilations.

Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/5e216522-ba3c-f0e6-7f97-5276d0270029@enterprisedb.com
2022-07-18 12:24:35 -07:00
Andres Freund 4f20506fe0 Add output path arg in generate-lwlocknames.pl
This is in preparation for building postgres with meson / ninja.

When building with meson, commands are run at the root of the build tree. Add
an option to put build output into the appropriate place. This can be utilized
by src/tools/msvc/ for a minor simplification, which also provides some
coverage for the new option.

Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/5e216522-ba3c-f0e6-7f97-5276d0270029@enterprisedb.com
2022-07-18 12:24:32 -07:00
Andres Freund b3a0d8324c Move snowball_create.sql creation into perl file
This is in preparation for building postgres with meson / ninja.

We already have duplicated code for this between the make and msvc
builds. Adding a third copy seems like a bad plan, thus move the generation
into a perl script.

As we don't want to rely on perl being available for builds from tarballs,
generate the file during distprep.

Author: Peter Eisentraut <peter@eisentraut.org>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/5e216522-ba3c-f0e6-7f97-5276d0270029@enterprisedb.com
2022-07-18 12:24:27 -07:00
Peter Eisentraut 976b06c663 Add another SQL/JSON error code
A code comment said that the standard does not define a number for
ERRCODE_SQL_JSON_ITEM_CANNOT_BE_CAST_TO_TARGET_TYPE, but this was
fixed in a later draft version of the standard, so use that number
now.
2022-07-18 14:26:43 +02:00
Andres Freund fd4bad1655 Remove now superfluous declarations of dlsym()ed symbols.
The prior commit declared them centrally.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20211101020311.av6hphdl6xbjbuif@alap3.anarazel.de
2022-07-17 17:29:32 -07:00
Tom Lane f49a9fc2bb Fix omissions in support for the "regcollation" type.
The patch that added regcollation doesn't seem to have been too
thorough about supporting it everywhere that other reg* types
are supported.  Fix that.  (The find_expr_references omission
is moderately serious, since it could result in missing expression
dependencies.  The others are less exciting.)

Noted while fixing bug #17483.  Back-patch to v13 where
regcollation was added.

Discussion: https://postgr.es/m/1423433.1652722406@sss.pgh.pa.us
2022-07-17 17:43:28 -04:00
Tom Lane 5e692dcaca Remove postmaster.c's reset_shared() wrapper function.
reset_shared just invokes CreateSharedMemoryAndSemaphores, so let's
get rid of it and invoke that directly.  This removes a confusing
seeming-inconsistency between the postmaster's startup sequence
and the startup sequence used in standalone mode.

Nathan Bossart, reviewed by Pavel Borisov

Discussion: https://postgr.es/m/20220329221702.GA559657@nathanxps13
2022-07-16 12:26:35 -04:00
Peter Eisentraut b449afb582 Attempt to fix compiler warning on old compiler
Build farm member lapwing (using gcc 4.7.2) didn't like one part of
9fd45870c1, raising a compiler warning.
Revert that for now.
2022-07-16 13:45:57 +02:00
Peter Eisentraut 9fd45870c1 Replace many MemSet calls with struct initialization
This replaces all MemSet() calls with struct initialization where that
is easily and obviously possible.  (For example, some cases have to
worry about padding bits, so I left those.)

(The same could be done with appropriate memset() calls, but this
patch is part of an effort to phase out MemSet(), so it doesn't touch
memset() calls.)

Reviewed-by: Ranier Vilela <ranier.vf@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/9847b13c-b785-f4e2-75c3-12ec77a3b05c@enterprisedb.com
2022-07-16 08:50:49 +02:00
Thomas Munro c94ae9d827 Emulate sigprocmask(), not sigsetmask(), on Windows.
Since commit a65e0864, we've required Unix systems to have
sigprocmask().  As noted in that commit's message, we were still
emulating the historical pre-standard sigsetmask() function in our
Windows support code.  Emulate standard sigprocmask() instead, for
consistency.

The PG_SETMASK() abstraction is now redundant and all calls could in
theory be replaced by plain sigprocmask() calls, but that isn't done by
this commit.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/3153247.1657834482%40sss.pgh.pa.us
2022-07-16 17:03:38 +12:00
Thomas Munro 3b8d23a3e1 Make dsm_impl_posix_resize more future-proof.
Commit 4518c798 blocks signals for a short region of code, but it
assumed that whatever called it had the signal mask set to UnBlockSig on
entry.  That may be true today (or may even not be, in extensions in the
wild), but it would be better not to make that assumption.  We should
save-and-restore the caller's signal mask.

The PG_SETMASK() portability macro couldn't be used for that, which is
why it wasn't done before.  But... considering that commit a65e0864
established back in 9.6 that supported POSIX systems have sigprocmask(),
and that this is POSIX-only code, there is no reason not to use standard
sigprocmask() directly to achieve that.

Back-patch to all supported releases, like 4518c798 and 80845b7c.

Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CA%2BhUKGKx6Biq7_UuV0kn9DW%2B8QWcpJC1qwhizdtD9tN-fn0H0g%40mail.gmail.com
2022-07-16 12:22:42 +12:00
Peter Eisentraut 3a0e385048 Log details for client certificate failures
Currently, debugging client certificate verification failures is
mostly limited to looking at the TLS alert code on the client side.
For simple deployments, sometimes it's enough to see "sslv3 alert
certificate revoked" and know exactly what needs to be fixed, but if
you add any more complexity (multiple CA layers, misconfigured CA
certificates, etc.), trying to debug what happened based on the TLS
alert alone can be an exercise in frustration.

Luckily, the server has more information about exactly what failed in
the chain, and we already have the requisite callback implemented as a
stub.  We fill that in, collect the data, and pass the constructed
error message back to the main code via a static variable.  This lets
us add our error details directly to the final "could not accept SSL
connection" log message, as opposed to issuing intermediate LOGs.

It ends up looking like

    LOG:  connection received: host=localhost port=43112
    LOG:  could not accept SSL connection: certificate verify failed
    DETAIL:  Client certificate verification failed at depth 1: unable to get local issuer certificate.
            Failed certificate data (unverified): subject "/CN=Test CA for PostgreSQL SSL regression test client certs", serial number 2315134995201656577, issuer "/CN=Test root CA for PostgreSQL SSL regression test suite".

The length of the Subject and Issuer strings is limited to prevent
malicious client certs from spamming the logs.  In case the truncation
makes things ambiguous, the certificate's serial number is also
logged.

Author: Jacob Champion <pchampion@vmware.com>
Discussion: https://www.postgresql.org/message-id/flat/d13c4a5787c2a3f83705124f0391e0738c796751.camel@vmware.com
2022-07-15 17:04:48 +02:00
Thomas Munro 80845b7c0b Don't clobber postmaster sigmask in dsm_impl_resize.
Commit 4518c798 intended to block signals in regular backends that
allocate DSM segments, but dsm_impl_resize() is also reached by
dsm_postmaster_startup().  It's not OK to clobber the postmaster's
signal mask, so only manipulate the signal mask when under the
postmaster.

Back-patch to all releases, like 4518c798.

Discussion: https://postgr.es/m/CA%2BhUKGKNpK%3D2OMeea_AZwpLg7Bm4%3DgYWk7eDjZ5F6YbozfOf8w%40mail.gmail.com
2022-07-15 02:00:09 +12:00
Tom Lane 7c0eb3c622 Tighten up parsing logic in gen_node_support.pl.
Teach this script to handle function pointer fields honestly.
Previously they were just silently ignored, but that's not likely to
be a behavior we can accept indefinitely.  This mostly entails fixing
it so that a field declaration spanning multiple lines can be parsed,
because we have a bunch of such fields that're laid out that way.
But that's a good improvement in its own right.

With that change and a minor regex adjustment, the only struct it
fails to parse in the node-defining headers is A_Const, because
of the embedded union.  The path of least resistance is to move
that union declaration outside the struct.

Having done those things, we can make it error out if it finds
any within-struct syntax it doesn't understand, which seems like
a pretty important property for robustness.

This commit doesn't change the output files at all; it's just in
the way of future-proofing.

Discussion: https://postgr.es/m/2593369.1657759779@sss.pgh.pa.us
2022-07-14 09:04:23 -04:00
Thomas Munro 5794491058 Avoid shadowing a variable in sync.c.
It was confusing to reuse the variable name 'entry' in two scopes.
Use distinct variable names.

Reported-by: Ranier Vilela <ranier.vf@gmail.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/CAEudQArDrFyQ15Am3rgWBunGBVZFDb90onTS8SRiFAWHeiLiFA%40mail.gmail.com
2022-07-15 00:06:32 +12:00
Thomas Munro 7bae3bbf62 Create a distinct wait event for POSIX DSM allocation.
Previously we displayed "DSMFillZeroWrite" while in posix_fallocate(),
because we shared the same wait event for "mmap" and "posix" DSM types.
Let's introduce a new wait event "DSMAllocate", to be more accurate.

Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220711174518.yldckniicknsxgzl%40awork3.anarazel.de
2022-07-14 23:56:28 +12:00
Thomas Munro 712704d353 Remove redundant ftruncate() for POSIX DSM memory.
In early releases of the DSM infrastructure, it was possible to resize
segments.  That was removed in release 12 by commit 3c60d0fa.  Now the
ftruncate() + posix_fallocate() sequence during DSM segment creation has
a redundant step: we're always extending from zero to the desired size,
so we might as well just call posix_fallocate().

Let's also include the remaining ftruncate() call (non-Linux POSIX
systems) in the wait event reporting, for good measure.

Discussion: https://postgr.es/m/CA%2BhUKGJSm-nq8s%2B_59zb7NbFQF-OS%3DxTnTAiGLrQpuSmU2y_1A%40mail.gmail.com
2022-07-14 23:56:22 +12:00
Thomas Munro 4518c798b2 Block signals while allocating DSM memory.
On Linux, we call posix_fallocate() on shm_open()'d memory to avoid
later potential SIGBUS (see commit 899bd785).

Based on field reports of systems stuck in an EINTR retry loop there,
there, we made it possible to break out of that loop via slightly odd
coding where the CHECK_FOR_INTERRUPTS() call was somewhat removed from
the loop (see commit 422952ee).

On further reflection, that was not a great choice for at least two
reasons:

1.  If interrupts were held, the CHECK_FOR_INTERRUPTS() would do nothing
and the EINTR error would be surfaced to the user.

2.  If EINTR was reported but neither QueryCancelPending nor
ProcDiePending was set, then we'd dutifully retry, but with a bit more
understanding of how posix_fallocate() works, it's now clear that you
can get into a loop that never terminates.  posix_fallocate() is not a
function that can do some of the job and tell you about progress if it's
interrupted, it has to undo what it's done so far and report EINTR, and
if signals keep arriving faster than it can complete (cf recovery
conflict signals), you're stuck.

Therefore, for now, we'll simply block most signals to guarantee
progress.  SIGQUIT is not blocked (see InitPostmasterChild()), because
its expected handler doesn't return, and unblockable signals like
SIGCONT are not expected to arrive at a high rate.  For good measure,
we'll include the ftruncate() call in the blocked region, and add a
retry loop.

Back-patch to all supported releases.

Reported-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Nicola Contu <nicola.contu@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220701154105.jjfutmngoedgiad3%40alvherre.pgsql
2022-07-14 18:01:27 +12:00
Michael Paquier 6203583b72 Remove support for Visual Studio 2013
No members of the buildfarm are using this version of Visual Studio,
resulting in all the code cleaned up here as being mostly dead, and
VS2017 is the oldest version still supported.

More versions could be cut, but the gain would be minimal, while
removing only VS2013 has the advantage to remove from the core code all
the dependencies on the value defined by _MSC_VER, where compatibility
tweaks have accumulated across the years mostly around locales and
strtof(), so that's a nice isolated cleanup.

Note that this commit additionally allows a revert of 3154e16.  The
versions of Visual Studio now supported range from 2015 to 2022.

Author: Michael Paquier
Reviewed-by: Juan José Santamaría Flecha, Tom Lane, Thomas Munro, Justin
Pryzby
Discussion: https://postgr.es/m/YoH2IMtxcS3ncWn+@paquier.xyz
2022-07-14 11:22:49 +09:00
Tom Lane ff33a8c887 Remove artificial restrictions on which node types have out/read funcs.
The initial version of gen_node_support.pl manually excluded most
utility statement node types from having out/read support, and
also some raw-parse-tree-only node types.  That was mostly to keep
the output comparable to the old hand-maintained code.  We'd like
to have out/read support for utility statements, for debugging
purposes and so that they can be included in new-style SQL functions;
so it's time to lift that restriction.

Most if not all of the previously-excluded raw-parse-tree-only node
types can appear in expression subtrees of utility statements, so
they have to be handled too.

We don't quite have full read support yet; certain custom_read_write
node types need to have their handwritten read functions implemented
before that will work.

Doing this allows us to drop the previous hack in _outQuery to not
dump the utilityStmt field in most cases, which means we no longer
need manually-maintained out/read functions for Query, so get rid
of those in favor of auto-generating them.

Fix a couple of omissions in gen_node_support.pl that are exposed
through having to handle more node types.

catversion bump forced because somebody was sloppy about the field
order in the manually-maintained Query out/read functions.
(Committers should note that almost all changes in parsenodes.h
are now grounds for a catversion bump.)
2022-07-13 11:48:17 -04:00
Peter Eisentraut 784cedda06 Allow specifying STORAGE attribute for a new table
Previously, the STORAGE specification was only available in ALTER
TABLE.  This makes it available in CREATE TABLE as well.

Also make the code and the documentation for STORAGE and COMPRESSION
attributes consistent.

Author:	Teodor Sigaev <teodor@sigaev.ru>
Author: Aleksander Alekseev <aleksander@timescale.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: wenjing zeng <wjzeng2012@gmail.com>
Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/de83407a-ae3d-a8e1-a788-920eb334f25b@sigaev.ru
2022-07-13 12:21:45 +02:00
Peter Eisentraut 503e3833ef Remove useless assertions
We don't need Assert(IsA(foo, String)) right before running
strVal(foo), since strVal() already does the assertion internally (via
castNode()).
2022-07-13 11:43:40 +02:00
Alvaro Herrera 7057bf2354
Fix XID list support some more
Read/out support in 5ca0fe5c8a was missing/incomplete, per Tom Lane.
Again, as far as core is concerned, this is not only dead code but also
untested; however, third parties may come to rely on it, so the standard
features should work.

Discussion: https://postgr.es/m/1548311.1657636605@sss.pgh.pa.us
2022-07-13 10:34:54 +02:00
Peter Eisentraut 88dad06b47 NLS: Put list of available languages into LINGUAS files
This moves the list of available languages from nls.mk into a separate
file called po/LINGUAS.  Advantages:

- It keeps the parts notionally managed by programmers (nls.mk)
  separate from the parts notionally managed by translators (LINGUAS).

- It's the standard practice recommended by the Gettext manual
  nowadays.

- The Meson build system also supports this layout (and of course
  doesn't know anything about our custom nls.mk), so this would enable
  sharing the list of languages between the two build systems.

(The MSVC build system currently finds all po files by globbing, so it
is not affected by this change.)

Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://www.postgresql.org/message-id/flat/557a9f5c-e871-edc7-2f58-a4140fb65b7b@enterprisedb.com
2022-07-13 08:19:17 +02:00
David Rowley f29199d319 Small cleanup of create_list_bounds()
When checking for interleaved partitions, we mark the partition as
interleaved when;

1. we find an earlier partition index when looping over the
sorted-by-Datum indexes[] array, or;

2. we find that the NULL partition allows some non-NULL Datum value.

In the code, as it was written in db632fbca we'll continue to check for
case 2 when we've already marked the partition as interleaved for case 1.
Here we make it so we don't bother marking the partition as interleaved
for case 2 when it's already been marked due to case 1.

Really all this saves is a useless call to bms_add_member(), but since
this code is new to PG15, it seems worth fixing it now to save anyone the
trouble of complaining at some time in the future.  We have the
opportunity to improve this now before PG15 is out.  This might ease some
future back-patching pain.

Per report and patch by Zhihong Yu.  However, I slightly revised the
comments and altered the bms_add_member() code to match in both locations.
We already know that index is equal to boundinfo->null_index from the if
condition.

Author: Zhihong Yu
Discussion: https://postgr.es/m/CALNJ-vQbZR0pYxz9zQ5bqXVcwtGgNgVupeEpNT65HZ+yWZnc4g@mail.gmail.com
Backpatch-through: 15, same as db632fbca.
2022-07-13 17:01:01 +12:00
David Rowley c23e3e6beb Use list_copy_head() instead of list_truncate(list_copy(...), ...)
Truncating off the end of a freshly copied List is not a very efficient
way of copying the first N elements of a List.

In many of the cases that are updated here, the pattern was only being
used to remove the final element of a List.  That's about the best case
for it, but there were many instances where the truncate trimming the List
down much further.

4cc832f94 added list_copy_head(), so let's use it in cases where it's
useful.

Author: David Rowley
Discussion: https://postgr.es/m/1986787.1657666922%40sss.pgh.pa.us
2022-07-13 15:03:47 +12:00
David Rowley 4cc832f94a Tidy up code in get_cheapest_group_keys_order()
There are a few things that we could do a little better within
get_cheapest_group_keys_order():

1. We should be using list_free() rather than pfree() on a List.

2. We should use for_each_from() instead of manually coding a for loop to
skip the first n elements of a List

3. list_truncate(list_copy(...), n) is not a great way to copy the first n
elements of a list. Let's invent list_copy_head() for that.  That way we
don't need to copy the entire list just to truncate it directly
afterwards.

4. We can simplify finding the cheapest cost by setting the cheapest cost
variable to DBL_MAX.  That allows us to skip special-casing the initial
iteration of the loop.

Author: David Rowley
Discussion: https://postgr.es/m/CAApHDvrGyL3ft8waEkncG9y5HDMu5TFFJB1paoTC8zi9YK97Nw@mail.gmail.com
Backpatch-through: 15, where get_cheapest_group_keys_order was added.
2022-07-13 14:02:20 +12:00
Tom Lane e64cdab003 Invent qsort_interruptible().
Justin Pryzby reported that some scenarios could cause gathering
of extended statistics to spend many seconds in an un-cancelable
qsort() operation.  To fix, invent qsort_interruptible(), which is
just like qsort_arg() except that it will also do CHECK_FOR_INTERRUPTS
every so often.  This bloats the backend by a couple of kB, which
seems like a good investment.  (We considered just enabling
CHECK_FOR_INTERRUPTS in the existing qsort and qsort_arg functions,
but there are some callers for which that'd demonstrably be unsafe.
Opt-in seems like a better way.)

For now, just apply qsort_interruptible() in statistics collection.
There's probably more places where it could be useful, but we can
always change other call sites as we find problems.

Back-patch to v14.  Before that we didn't have extended stats on
expressions, so that the problem was less severe.  Also, this patch
depends on the sort_template infrastructure introduced in v14.

Tom Lane and Justin Pryzby

Discussion: https://postgr.es/m/20220509000108.GQ28830@telsasoft.com
2022-07-12 16:30:36 -04:00
Tom Lane eea9fa9b25 Add defenses against unexpected changes in the NodeTag enum list.
Having different build systems producing different contents of the
NodeTag enum would be catastrophic for extension ABI stability.
But that ordering depends on the order in which gen_node_support.pl
processes its input files.  It seems too fragile to let the Makefiles,
MSVC build scripts, and soon meson build scripts all set this order
independently.  As a klugy but serviceable solution, put a canonical
copy of the file list into gen_node_support.pl itself, and check that
against the files given on the command line.

Also, while it's fine to add and delete node tags during development,
we must not let the assigned NodeTag values change unexpectedly in
stable branches.  Add a cross-check that can be enabled when a branch
is forked off (or later, but that is a time when we're unlikely to
miss doing it).  It just checks that the last auto-assigned number
doesn't change, which is simplistic but will catch the most likely
sorts of mistakes.

From time to time we do need to add a node tag in a stable branch.
To support doing that without changing the branch's auto-assigned
tag numbers, invent pg_node_attr(nodetag_number(VALUE)) which can
be used to give such a node a hand-assigned tag above the last
auto-assigned one.

Discussion: https://postgr.es/m/1249010.1657574337@sss.pgh.pa.us
2022-07-12 11:22:52 -04:00
Tom Lane ca187d7455 Invent nodetag_only attribute for Nodes.
This allows explaining gen_node_support.pl's handling of execnodes.h
and some other input files as being a shortcut for explicit marking
of all their node declarations as pg_node_attr(nodetag_only).
I foresee that someday we might need to be more fine-grained about
that, and this change provides the infrastructure needed to do so.
For now, it just allows removal of the script's klugy special case
for CallContext and InlineCodeBlock.

Discussion: https://postgr.es/m/75063.1657410615@sss.pgh.pa.us
2022-07-12 10:46:58 -04:00
Robert Haas 09c5acee8e Rename some functions to mention Relation instead of RelFileLocator.
This is definitely shorter, and hopefully clearer.

Kyotaro Horiguchi, reviewed by Dilip Kumar and by me

Discussion: http://postgr.es/m/20220707.174436.1885393789789795413.horikyota.ntt@gmail.com
2022-07-12 10:26:48 -04:00
Alvaro Herrera 5ca0fe5c8a
Add copy/equal support for XID lists
Commit f10a025cfe added support for List to store Xids, but didn't
handle the new type in all cases.  Add some obviously necessary pieces.
As far as I am aware, this is all dead code as far as core code is
concerned, but it seems unacceptable not to have it in case third-party
code wants to rely on this type of list.  (Some parts of the List API
remain unimplemented, but that can be fixed as and when needed -- see
lack of list_intersection_oid, list_deduplicate_int as precedents.)

Discussion: https://postgr.es/m/20220708164534.nbejhgt4ajz35p65@alvherre.pgsql
2022-07-12 16:11:04 +02:00
Fujii Masao 3b00a944a9 Support TRUNCATE triggers on foreign tables.
Now some foreign data wrappers support TRUNCATE command.
So it's useful to support TRUNCATE triggers on foreign tables for
audit logging or for preventing undesired truncation.

Author: Yugo Nagata
Reviewed-by: Fujii Masao, Ian Lawrence Barwick
Discussion: https://postgr.es/m/20220630193848.5b02e0d6076b86617a915682@sraoss.co.jp
2022-07-12 09:18:02 +09:00
Thomas Munro 718aa43a4e Further tidy-up for old CPU architectures.
Further to commit 92d70b77, let's drop the code we carry for the
following untested architectures: M68K, M88K, M32R, SuperH.  We have no
idea if anything actually works there, and surely as vintage hardware
and microcontrollers they would be underpowered for modern purposes.

We could always consider re-adding SuperH based on evidence of usage and
build farm support, if someone shows up to provide it.

While here, SPARC is usually written in all caps.

Suggested-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Robert Haas <robertmhaas@gmail.com> (the idea, not the patch)
Discussion: https://postgr.es/m/959917.1657522169%40sss.pgh.pa.us
2022-07-12 11:05:32 +12:00
Jeff Davis b40baa96a7 Provide log_status_format(), useful for an emit_log_hook.
Refactor so that log_line_prefix() is a thin wrapper over a new
function log_status_format(), and move the implementation to the
latter. Export log_status_format() so that it can be used by an
emit_log_hook.

Discussion: https://postgr.es/m/39c8197652f4d3050aedafae79fa5af31096505f.camel%40j-davis.com
Reviewed-by: Michael Paquier, Alvaro Herrera
2022-07-11 12:29:33 -07:00
Tom Lane bf022d337e Rationalize order of input files for gen_node_support.pl.
Per a question from Andres Freund.  While here, also make the
list of nodetag-only files easier to compare to the full list
of input files.

Discussion: https://postgr.es/m/20220710214622.haiektrjzisob6rl@awork3.anarazel.de
2022-07-11 13:38:47 -04:00
Robert Haas b2d5b4c6e0 Fix mistake in comment.
Kyotaro Horiguchi

Discussion: http://postgr.es/m/20220708.145951.382076151410075693.horikyota.ntt@gmail.com
2022-07-11 13:33:21 -04:00
Peter Eisentraut 2cd2569c72 Convert macros to static inline functions (bufpage.h)
Remove PageIsValid() and PageSizeIsValid(), which weren't used and
seem unnecessary.

Some code using these formerly-macros needs some adjustments because
it was previously playing loose with the Page vs. PageHeader types,
which is no longer possible with the functions instead of macros.

Reviewed-by: Amul Sul <sulamul@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/5b558da8-99fb-0a99-83dd-f72f05388517%40enterprisedb.com
2022-07-11 07:21:52 +02:00
Thomas Munro eed959a457 Fix lock assertions in dshash.c.
dshash.c previously maintained flags to be able to assert that you
didn't hold any partition lock.  These flags could get out of sync with
reality in error scenarios.

Get rid of all that, and make assertions about the locks themselves
instead.  Since LWLockHeldByMe() loops internally, we don't want to put
that inside another loop over all partition locks.  Introduce a new
debugging-only interface LWLockAnyHeldByMe() to avoid that.

This problem was noted by Tom and Andres while reviewing changes to
support the new shared memory stats system, and later showed up in
reality while working on commit 389869af.

Back-patch to 11, where dshash.c arrived.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220311012712.botrpsikaufzteyt@alap3.anarazel.de
Discussion: https://postgr.es/m/CA%2BhUKGJ31Wce6HJ7xnVTKWjFUWQZPBngxfJVx4q0E98pDr3kAw%40mail.gmail.com
2022-07-11 16:43:29 +12:00
Michael Paquier 0a6be1f0ec Improve error message with JSON_SERIALIZE()
The error message introduced in 3c633f3 can share the same format string
with an existing message used for JSON(), reducing the translation
effort.

Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20220708.154135.2123613118233840495.horikyota.ntt@gmail.com
Backpatch-through: 15
2022-07-11 11:20:15 +09:00
Michael Paquier 8445f5a21d Improve two comments related to a boolean DefElem's value
The original comments mentioned a "parameter" as something not defined
in a fast-exit path to assume a true status.  This is rather confusing
as the parameter DefElem is defined, and the intention is to check if
its value is defined.  This improves both comments to mention the value
assigned to the DefElem's value instead, so as future patches are able
to catch the tweak if this code pattern gets copied around more.

Author: Peter Smith
Discussion: https://postgr.es/m/CAHut+Pv0yWynWTmp4o34s0d98xVubys9fy=p0YXsZ5_sUcNnMw@mail.gmail.com
2022-07-11 11:07:33 +09:00
Tom Lane 8eccaf6525 Make assorted quality-of-life improvements in gen_node_support.pl.
Fix incorrect reporting of the location of errors (such as bogus
node attributes).  Add header comments to the generated files,
containing copyright notices and reminders that they are generated
files, as we do in other file-generating scripts.  Arrange to not
leave a clutter of temporary files when the script detects an error.

Discussion: https://postgr.es/m/3843645.1657385930@sss.pgh.pa.us
2022-07-09 15:15:05 -04:00
Tom Lane 3cd0ac9878 Doc: rearrange high-level commentary about node support coverage.
copyfuncs.c and friends no longer seem like great places to put
high-level remarks about what's covered and what isn't.  Move that
material to backend/nodes/README and other more-prominent places.
Add back (versions of) some remarks that disappeared in 2be87f092.

Discussion: https://postgr.es/m/3843645.1657385930@sss.pgh.pa.us
2022-07-09 15:10:15 -04:00
Peter Eisentraut 2be87f092a Remove code sections obsoleted by node support automation
This removes the code sections that were ifdef'ed out by
964d01ae90.
2022-07-09 15:06:01 +02:00
Peter Eisentraut c842736006 Fix vpath build 2022-07-09 09:44:09 +02:00
Peter Eisentraut 964d01ae90 Automatically generate node support functions
Add a script to automatically generate the node support functions
(copy, equal, out, and read, as well as the node tags enum) from the
struct definitions.

For each of the four node support files, it creates two include files,
e.g., copyfuncs.funcs.c and copyfuncs.switch.c, to include in the main
file.  All the scaffolding of the main file stays in place.

I have tried to mostly make the coverage of the output match what is
currently there.  For example, one could now do out/read coverage of
utility statement nodes, but I have manually excluded those for now.
The reason is mainly that it's easier to diff the before and after,
and adding a bunch of stuff like this might require a separate
analysis and review.

Subtyping (TidScan -> Scan) is supported.

For the hard cases, you can just write a manual function and exclude
generating one.  For the not so hard cases, there is a way of
annotating struct fields to get special behaviors.  For example,
pg_node_attr(equal_ignore) has the field ignored in equal functions.

(In this patch, I have only ifdef'ed out the code to could be removed,
mainly so that it won't constantly have merge conflicts.  It will be
deleted in a separate patch.  All the code comments that are worth
keeping from those sections have already been moved to the header
files where the structs are defined.)

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/c1097590-a6a4-486a-64b1-e1f9cc0533ce%40enterprisedb.com
2022-07-09 08:53:59 +02:00
Alexander Korotkov e57519a463 Add missing inequality searches to rbtree
PostgreSQL contains the implementation of the red-black tree.  The red-black
tree is the ordered data structure, and one of its advantages is the ability
to do inequality searches.  This commit adds rbt_find_less() and
rbt_find_great() functions implementing these searches.  While these searches
aren't yet used in the core code, they might be useful for extensions.

Discussion: https://postgr.es/m/CAGRrpzYE8-7GCoaPjOiL9T_HY605MRax-2jgTtLq236uksZ1Sw%40mail.gmail.com
Author: Steve Chavez, Alexander Korotkov
Reviewed-by: Alexander Korotkov
2022-07-08 22:00:03 +03:00
Alexander Korotkov 8d51d7f403 Use C99 designator in the rbtree sentinel definition
This change should improve the code readability.

Discussion: https://postgr.es/m/CAGRrpzYE8-7GCoaPjOiL9T_HY605MRax-2jgTtLq236uksZ1Sw%40mail.gmail.com
Author: Steve Chavez, Alexander Korotkov
Reviewed-by: Alexander Korotkov
2022-07-08 22:00:03 +03:00
Peter Eisentraut bf1f4a364d Adjust node serialization tag of A_Expr for consistency
Changed from AEXPR to A_EXPR for consistency.

Discussion: https://www.postgresql.org/message-id/2592455.1657140387%40sss.pgh.pa.us
2022-07-08 11:03:45 +02:00
Peter Eisentraut 251154bebe Remove T_Join and T_Plan
These are abstract node types that don't need to have a node tag
defined.

Discussion: https://www.postgresql.org/message-id/2592455.1657140387%40sss.pgh.pa.us
2022-07-08 10:40:44 +02:00
Thomas Munro 0ad5b48e58 Remove HP/Intel Itanium support.
This CPU architecture has been discontinued.  We already removed HP-UX
support, we never supported Windows/Itanium, and the open source
operating systems that a vintage hardware owner might hope to run have
all either ended Itanium support or never fully released support (NetBSD
may eventually).  The extra code we carry for this rare ISA is now
untested.  It seems like a good time to remove it.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/1415825.1656893299%40sss.pgh.pa.us
2022-07-08 14:14:57 +12:00
Thomas Munro 9db300ce6e Remove HP-UX port.
HP-UX hardware is no longer produced, build farm coverage recently
ended, and there are no known active maintainers targeting this OS.
Since there is a major rewrite of the build system in the pipeline for
PostgreSQL 16, and that requires development, testing and maintainance
for each OS and tool chain, it seems like a good time to drop support
for:

 * HP-UX, the operating system.
 * HP aCC, the HP-UX native compiler.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Discussion: https://postgr.es/m/1415825.1656893299%40sss.pgh.pa.us
2022-07-08 14:05:05 +12:00
Andrew Dunstan 3c633f32b9 Only allow returning string types or bytea from json_serialize
These are documented to be the allowed types for the RETURNING clause,
but the restriction was not being enforced, which caused a segfault if
another type was specified. Add some testing for this.

Per report from a.kozhemyakin

Backpatch to release 15.
2022-07-07 17:40:02 -04:00
Tom Lane 8821054210 Remove stray references to lefttree/righttree in the executor.
The general convention in the executor is to refer to child plans
and planstates via the outerPlan[State] and innerPlan[State]
macros, but a few places didn't do it like that.  For consistency
and readability, convert all the stragglers to use the macros.
(See also commit 40f42d2a3, which did some similar cleanup a few
years ago, but missed these cases.)

Richard Guo

Discussion: https://postgr.es/m/CAMbWs4-vYhh1xsa_veah4PUed2Xq=Ed_YH3=Mqt5A3Y=EgfCEg@mail.gmail.com
2022-07-07 11:23:40 -04:00
Fujii Masao 62c46eee22 Add checkpoint and REDO LSN to log_checkpoints message.
It is useful for debugging purposes to report the checkpoint LSN and
REDO LSN in log_checkpoints message. It can give more context while
analyzing checkpoint-related issues. pg_controldata reports the last
checkpoint LSN and REDO LSN, but having this information alongside
the log message helps analyze issues that happened previously,
connect the dots and identify the root cause.

Author: Bharath Rupireddy, Kyotaro Horiguchi
Reviewed-by: Michael Paquier, Julien Rouhaud, Nathan Bossart, Fujii Masao, Greg Stark
Discussion: https://postgr.es/m/CALj2ACWt6kqriAHrO+AJj+OmP=suwbktHT5JoYAn-nqZe2gd2g@mail.gmail.com
2022-07-07 22:37:54 +09:00
Dean Rasheed 8d367a44d3 Fix alias matching in transformLockingClause().
When locking a specific named relation for a FOR [KEY] UPDATE/SHARE
clause, transformLockingClause() finds the relation to lock by
scanning the rangetable for an RTE with a matching eref->aliasname.
However, it failed to account for the visibility rules of a join RTE.

If a join RTE doesn't have a user-supplied alias, it will have a
generated eref->aliasname of "unnamed_join" that is not visible as a
relation name in the parse namespace. Such an RTE needs to be skipped,
otherwise it might be found in preference to a regular base relation
with a user-supplied alias of "unnamed_join", preventing it from being
locked.

In addition, if a join RTE doesn't have a user-supplied alias, but
does have a join_using_alias, then the RTE needs to be matched using
that alias rather than the generated eref->aliasname, otherwise a
misleading "relation not found" error will be reported rather than a
"join cannot be locked" error.

Backpatch all the way, except for the second part which only goes back
to 14, where JOIN USING aliases were added.

Dean Rasheed, reviewed by Tom Lane.

Discussion: https://postgr.es/m/CAEZATCUY_KOBnqxbTSPf=7fz9HWPnZ5Xgb9SwYzZ8rFXe7nb=w@mail.gmail.com
2022-07-07 13:08:08 +01:00
Michael Paquier 495ed0ef2d Make Windows 10 the minimal runtime requirement for WIN32
This commit bumps the runtime value of _WIN32_WINNT to be 0x0A00 for any
builds on Windows.  Hence, this makes Windows 10 the minimal requirement
when running PostgreSQL under WIN32, be it for builds of Cygwin, MinGW
or Visual Studio.

The previous minimal runtime version was either Windows Vista when
building with at least Visual Studio 2015 or Windows XP for the rest.

Windows 10 is the most modern version supported by Microsoft, and per
discussion, as we don't have buildfarm members that run older versions
anymore, this is the minimal supported version that suits better for our
needs.  This will actually make easier the development of some patches,
two being async I/O and large page handling by avoiding a lot of
compatibility gotchas, on platforms that have most likely few users
anyway.

It is possible to remove MIN_WINNT in win32.h and the macros
IsWindowsXXXOrGreater() that were used in the code at runtime to check
which version of Windows was getting used.  The change in pg_locale.c
comes from Juan.  Note that all my tests passed, and that the CI is
green.  The buildfarm will quickly tell if this needs more adjustments.

Author: Michael Paquier, Juan José Santamaría Flecha
Reviewed-by: Thomas Munro
Discussion: https://postgr.es/m/Yo7tHKD8VCkeNi71@paquier.xyz
2022-07-07 13:25:45 +09:00
Andres Freund f4d3ca421d pgstat: slru: remove outdated comment
That comment might have been true at some point during development, but
definitely isn't anymore.

Reported-By: Melanie Plageman <melanieplageman@gmail.com>
Backpatch: 15-
2022-07-06 15:57:29 -07:00
Tom Lane 55b8ac8172 Fix wrong field order in _readMergeWhenClause().
We hadn't noticed this because it's dead code: there is no
situation where we read raw parse trees from text format.
So maybe the right fix is to remove the function altogether,
but I'll forbear for now; it's not the only dead code in
readfuncs.c, I think.

Noted while comparing existing code to the results of
Peter's auto-generation script.
2022-07-06 17:26:42 -04:00
David Rowley 0229106afa Overload index_form_tuple to allow the memory context to be supplied
40af10b57 changed things so we make use of a generation memory context for
storing tuples to be sorted by tuplesort.c. That change does not play
nicely with the changes made in 9f03ca915 (back in 2014). That commit
changed things so that index_form_tuple() is called while switched into
the tuplestore's tuplecontext. In order to fetch the tuple from the index,
index_form_tuple() must do various memory allocations which are unrelated
to the storage of the final returned tuple. Although all of these
allocations are pfree'd, the fact that we now use a generation context
means that the memory for these pfree'd allocations won't be used again by
any other allocation due to generation.c's lack of freelists.  This could
result in sorts used for building indexes exceeding maintenance_work_mem
by a very large amount.

Here we fix it so we no longer allocate anything apart from the tuple
itself into the generation context by adding a new version of
index_form_tuple named index_form_tuple_context, which can be called to
specify the MemoryContext to allocate the tuple into.

Discussion: https://postgr.es/m/CAApHDvrHQkiFRHiGiAS-LMOvJN-eK-s762=tVzBz8ZqUea-a_A@mail.gmail.com
Backpatch-through: 15, where 40af10b57 was added.
2022-07-07 08:14:00 +12:00
Andres Freund 7b64e4b3fa pgstat: drop subscription stats without slot as well, fix comment
There's no reason anymore to only drop subscription stats if associated with a
slot, now that stats drops are transactional. And since there's now no other
cleanup of stats, this would lead to stats for slot-less subscriptions to get
leaked (however most slot-less subs won't have stats).

Additionally, the comment referring to autovacuum cleaning up stats was
clearly outdated.

Author: Masahiko Sawada <sawada.mshk@gmail.com>
Discussion: https://postgr.es/m/CAD21AoAwiby3HeJE7vJe16Gr75RFfJ640dyHqvsiUhyKJTXPtw@mail.gmail.com
Backpatch: 15-
2022-07-06 08:56:34 -07:00
Robert Haas b0a55e4329 Change internal RelFileNode references to RelFileNumber or RelFileLocator.
We have been using the term RelFileNode to refer to either (1) the
integer that is used to name the sequence of files for a certain relation
within the directory set aside for that tablespace/database combination;
or (2) that value plus the OIDs of the tablespace and database; or
occasionally (3) the whole series of files created for a relation
based on those values. Using the same name for more than one thing is
confusing.

Replace RelFileNode with RelFileNumber when we're talking about just the
single number, i.e. (1) from above, and with RelFileLocator when we're
talking about all the things that are needed to locate a relation's files
on disk, i.e. (2) from above. In the places where we refer to (3) as
a relfilenode, instead refer to "relation storage".

Since there is a ton of SQL code in the world that knows about
pg_class.relfilenode, don't change the name of that column, or of other
SQL-facing things that derive their name from it.

On the other hand, do adjust closely-related internal terminology. For
example, the structure member names dbNode and spcNode appear to be
derived from the fact that the structure itself was called RelFileNode,
so change those to dbOid and spcOid. Likewise, various variables with
names like rnode and relnode get renamed appropriately, according to
how they're being used in context.

Hopefully, this is clearer than before. It is also preparation for
future patches that intend to widen the relfilenumber fields from its
current width of 32 bits. Variables that store a relfilenumber are now
declared as type RelFileNumber rather than type Oid; right now, these
are the same, but that can now more easily be changed.

Dilip Kumar, per an idea from me. Reviewed also by Andres Freund.
I fixed some whitespace issues, changed a couple of words in a
comment, and made one other minor correction.

Discussion: http://postgr.es/m/CA+TgmoamOtXbVAQf9hWFzonUo6bhhjS6toZQd7HZ-pmojtAmag@mail.gmail.com
Discussion: http://postgr.es/m/CA+Tgmobp7+7kmi4gkq7Y+4AM9fTvL+O1oQ4-5gFTT+6Ng-dQ=g@mail.gmail.com
Discussion: http://postgr.es/m/CAFiTN-vTe79M8uDH1yprOU64MNFE+R3ODRuA+JWf27JbhY4hJw@mail.gmail.com
2022-07-06 11:39:09 -04:00
David Rowley fe3caa1439 Remove size increase in ExprEvalStep caused by hashed saops
50e17ad28 increased the size of ExprEvalStep from 64 bytes up to 88 bytes.
Lots of effort was spent during the development of the current expression
evaluation code to make an instance of this struct as small as possible.
Making this struct larger than needed reduces CPU cache efficiency during
expression evaluation which causes noticeable slowdowns during query
execution.

In order to reduce the size of the struct, here we remove the fn_addr
field. The values from this field can be obtained via fcinfo, just with
some extra pointer dereferencing. The extra indirection does not seem to
cause any noticeable slowdowns.

Various other fields have been moved into the ScalarArrayOpExprHashTable
struct. These fields are only used when the ScalarArrayOpExprHashTable
pointer has already been dereferenced, so no additional pointer
dereferences occur for these. Here we also make hash_fcinfo_data the last
field in ScalarArrayOpExprHashTable so that we can avoid a further pointer
dereference to get the FunctionCallInfoBaseData. This also saves a call to
palloc().

50e17ad28 was added in 14, but it's too late to adjust the size of the
ExprEvalStep in that version, so here we just backpatch to 15, which is
currently in beta.

Author: Andres Freund, David Rowley
Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de
Backpatch-through: 15
2022-07-06 19:40:32 +12:00
Peter Eisentraut 16d52fc89d Refactor sending of DataRow messages in replication protocol
Some routines open-coded the construction of DataRow messages.  Use
TupOutputState struct and associated functions instead, which was
already done in some places.

SendTimeLineHistory() is a bit more complicated and isn't converted by
this.

Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/7e4fdbdc-699c-4cd0-115d-fb78a957fc22@enterprisedb.com
2022-07-06 08:42:56 +02:00
Michael Paquier d4bfe41281 autho_explain: Add GUC to log query parameters
auto_explain.log_parameter_max_length is a new GUC part of the
extension, similar to the corresponding core setting, that controls the
inclusion of query parameters in the logged explain output.

More tests are added to check the behavior of this new parameter: when
parameters logged in full (the default of -1), when disabled (value of
0) and when partially truncated (value different than the two others).

Author: Dagfinn Ilmari Mannsåker
Discussion: https://postgr.es/m/87ee09mohb.fsf@wibble.ilmari.org
2022-07-06 09:55:30 +09:00
Andres Freund 056cc366fa pgstat: reduce timer overhead by leaving timer running.
Previously the timer was enabled whenever there were any pending stats after
executing a statement, just to then be disabled again when not idle
anymore. That lead to an increase in GetCurrentTimestamp() calls from within
timeout.c compared to 14.

To avoid that increase, leave the timer enabled until stats are reported,
rather than until idle. The timer is only disabled once the pending stats have
been reported.

For me this fixes the increase in GetCurrentTimestamp() calls, there now are
fewer calls in 15 than in 14, in the previously slowed down workload.

While at it, also update assertion in pgstat_report_stat() to be more precise.

Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de
Backpatch: 15-
2022-07-05 11:54:46 -07:00
Andres Freund 67b26703b4 expression eval: Fix EEOP_JSON_CONSTRUCTOR and EEOP_JSONEXPR size.
The new expression step types increased the size of ExprEvalStep by ~4 for all
types of expression steps, slowing down expression evaluation noticeably. Move
them out of line.

There's other issues with these expression steps, but addressing them is
largely independent of this aspect.

Author: Andres Freund <andres@anarazel.de>
Reviewed-By: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de
Backpatch: 15-
2022-07-05 11:25:08 -07:00
Andres Freund 3f8148c256 Revert 019_replslot_limit.pl related debugging aids.
This reverts most of 91c0570a79, f28bf667f6, fe0972ee5e, afdeff1052. The
only thing left is the retry loop in 019_replslot_limit.pl that avoids
spurious failures by retrying a couple times.

We haven't seen any hard evidence that this is caused by anything but slow
process shutdown. We did not find any cases where walsenders did not vanish
after waiting for longer. Therefore there's no reason for this debugging code
to remain.

Discussion: https://postgr.es/m/20220530190155.47wr3x2prdwyciah@alap3.anarazel.de
Backpatch: 15-
2022-07-05 11:01:10 -07:00
Robert Haas b9eb0ff09e Rename pg_checkpointer predefined role to pg_checkpoint.
This is more consistent with how other predefined roles that confer
specific privileges are named.

Nathan Bosart

Discussion: http://postgr.es/m/CA+TgmoatH7+yYe+A8uJFNogg3VUDtFE6c-77yHAY8TRWR7oqyw@mail.gmail.com
2022-07-05 13:31:42 -04:00
Tom Lane 8d9f9634ef Fix errors in copyfuncs/equalfuncs support for JSON node types.
Noted while comparing existing code to the output of the proposed
patch to automate creation of these functions.  Some of the changes
are just cosmetic, but others represent real bugs.  I've not
attempted to analyze the user-visible impact.

Back-patch to v15 where this code came in.

Discussion: https://postgr.es/m/1794155.1656984188@sss.pgh.pa.us
2022-07-05 11:12:33 -04:00
Peter Eisentraut 6ffff0fd22 Fix pg_prepared_statements.result_types for DML statements
Amendment to 84ad713cf85aeffee5dd39f62d49a1b9e34632da: Not all
prepared statements have a result descriptor.  As currently coded,
this would crash when reading pg_prepared_statements.  Make those
cases return null for result_types instead.  Also add a test case for
it.
2022-07-05 10:26:36 +02:00
Peter Eisentraut 84ad713cf8 Add result_types column to pg_prepared_statements view
Containing the types of the columns returned by the prepared
statement.

Prompted by question from IRC user mlvzk.

Author: Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
Discussion: https://www.postgresql.org/message-id/flat/871qwpo7te.fsf@wibble.ilmari.org
2022-07-05 07:23:32 +02:00
Michael Paquier eb64ceac7e Remove durable_rename_excl()
A previous commit replaced all the calls to this function with
durable_rename() as of dac1ff3, making it used nowhere in the tree.
Using it in extension code is also risky based on the issues described
in this previous commit, so let's remove it.  This makes possible the
removal of HAVE_WORKING_LINK.

Author: Nathan Bossart
Reviewed-by: Robert Haas, Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/20220407182954.GA1231544@nathanxps13
2022-07-05 12:54:25 +09:00
Michael Paquier dac1ff3090 Replace durable_rename_excl() by durable_rename(), take two
durable_rename_excl() attempts to avoid overwriting any existing files
by using link() and unlink(), and it falls back to rename() on some
platforms (aka WIN32), which offers no such overwrite protection.  Most
callers use durable_rename_excl() just in case there is an existing
file, but in practice there shouldn't be one (see below for more
details).

Furthermore, failures during durable_rename_excl() can result in
multiple hard links to the same file.  As per Nathan's tests, it is
possible to end up with two links to the same file in pg_wal after a
crash just before unlink() during WAL recycling.  Specifically, the test
produced links to the same file for the current WAL file and the next
one because the half-recycled WAL file was re-recycled upon restarting,
leading to WAL corruption.

This change replaces all the calls of durable_rename_excl() to
durable_rename().  This removes the protection against accidentally
overwriting an existing file, but some platforms are already living
without it and ordinarily there shouldn't be one.  The function itself
is left around in case any extensions are using it.  It will be removed
on HEAD via a follow-up commit.

Here is a summary of the existing callers of durable_rename_excl() (see
second discussion link at the bottom), replaced by this commit.  First,
basic_archive used it to avoid overwriting an archive concurrently
created by another server, but as mentioned above, it will still
overwrite files on some platforms.  Second, xlog.c uses it to recycle
past WAL segments, where an overwrite should not happen (origin of the
change at f0e37a8) because there are protections about the WAL segment
to select when recycling an entry.  The third and last area is related
to the write of timeline history files.  writeTimeLineHistory() will
write a new timeline history file at the end of recovery on promotion,
so there should be no such files for the same timeline.
What remains is writeTimeLineHistoryFile(), that can be used in parallel
by a WAL receiver and the startup process, and some digging of the
buildfarm shows that EEXIST from a WAL receiver can happen with an error
of "could not link file \"pg_wal/xlogtemp.NN\" to \"pg_wal/MM.history\",
which would cause an automatic restart of the WAL receiver as it is
promoted to FATAL, hence this should improve the stability of the WAL
receiver as rename() would overwrite an existing TLI history file
already fetched by the startup process at recovery.

This is a bug fix, but knowing the unlikeliness of the problem involving
one or more crashes at an exceptionally bad moment, no backpatch is
done.  Also, I want to be careful with such changes (aaa3aed did the
opposite of this change by removing HAVE_WORKING_LINK so as Windows
would do a link() rather than a rename() but this was not
concurrent-safe).  A backpatch could be revisited in the future.  This
is the second time this change is attempted, ccfbd92 being the first
one, but this time no assertions are added for the case of a TLI history
file written concurrently by the WAL receiver or the startup process
because we can expect one to exist (some of the TAP tests are able to
trigger with a proper timing).

Author: Nathan Bossart
Reviewed-by: Robert Haas, Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/20220407182954.GA1231544@nathanxps13
Discussion: https://postgr.es/m/Ym6GZbqQdlalSKSG@paquier.xyz
2022-07-05 10:16:12 +09:00