We're running out of bits for new permissions. This change doubles the
number of permissions we can accomodate from 16 to 32, so the
forthcoming new ones for vacuum/analyze don't exhaust the pool.
Nathan Bossart
Reviewed by: Bharath Rupireddy, Kyotaro Horiguchi, Stephen Frost, Robert
Haas, Mark Dilger, Tom Lane, Corey Huinker, David G. Johnston, Michael
Paquier.
Discussion: https://postgr.es/m/20220722203735.GB3996698@nathanxps13
Pass VACUUM parameters (VacuumParams state) to vacuum_set_xid_limits()
directly, rather than passing most individual VacuumParams fields as
separate arguments.
Also make vacuum_set_xid_limits() output parameter symbol names match
those used by its vacuumlazy.c caller.
Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-Wz=TE7gW5DgSahDkf0UEZigFGAoHNNN6EvSrdzC=Kn+hrA@mail.gmail.com
We shouldn't ever need to rely on whether HEAP_XMAX_INVALID is set in
t_infomask when considering whether or not an xmax should be deemed
already frozen, since that status flag is just a hint. The only
acceptable representation for an "xmax_already_frozen" raw xmax field is
the transaction ID value zero (also known as InvalidTransactionId).
Adjust code that superficially appeared to rely on HEAP_XMAX_INVALID to
make the rule about xmax_already_frozen clear. Also avoid needlessly
rereading the tuple's raw xmax.
Oversight in bugfix commit d2599ecf. There is no evidence that this
ever led to incorrect behavior, so no backpatch. The worst consequence
of this bug was that VACUUM could hypothetically fail to notice and
report on certain kinds of corruption, which seems fairly benign.
Author: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-Wzkh3DMCDRPfhZxj9xCq9v3WmzvmbiCpf1dNKUBPadhCbQ@mail.gmail.com
Examine ParseNamespaceItem flags to detect whether a column name
is unreferenceable for lack of LATERAL, or could be referenced if
a qualified name were used, and give better hints for such cases.
Also, don't phrase the message to imply that there's only one
matching column when there is really more than one.
Many of the regression test output changes are not very interesting,
but just reflect reclassifying the "There is a column ... but it
cannot be referenced from this part of the query" messages as DETAIL
rather than HINT. They are details per our style guide, in the sense
of being factual rather than offering advice; and this change provides
room to offer actual HINTs about what to do.
While here, adjust the fuzzy-name-matching code to be a shade less
impenetrable. It was overloading the meanings of FuzzyAttrMatchState
fields way too much IMO, so splitting them into multiple fields seems
to make it clearer. It's not like we need to shave bytes in that
struct.
Per discussion of bug #17233 from Alexander Korolev.
Discussion: https://postgr.es/m/17233-afb9d806aaa64b17@postgresql.org
We've made multiple attempts at preventing get_actual_variable_range
from taking an unreasonable amount of time (3ca930fc3, fccebe421).
But there's still an issue for the very first planning attempt after
deletion of a large number of extremal-valued tuples. While that
planning attempt will set "killed" bits on the tuples it visits and
thereby reduce effort for next time, there's still a lot of work it
has to do to visit the heap and then set those bits. It's (usually?)
not worth it to do that much work at plan time to have a slightly
better estimate, especially in a context like this where the table
contents are known to be mutating rapidly.
Therefore, let's bound the amount of work to be done by giving up
after we've visited 100 heap pages. Giving up just means we'll
fall back on the extremal value recorded in pg_statistic, so it
shouldn't mean that planner estimates suddenly become worthless.
Note that this means we'll still gradually whittle down the problem
by setting a few more index "killed" bits in each planning attempt;
so eventually we'll reach a good state (barring further deletions),
even in the absence of VACUUM.
Simon Riggs, per a complaint from Jakub Wartak (with cosmetic
adjustments by me). Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAKZiRmznOwi0oaV=4PHOCM4ygcH4MgSvt8=5cu_vNCfc8FSUug@mail.gmail.com
Once a logical slot has acquired a catalog_xmin, it doesn't let go of
it, even when invalidated by exceeding the max_slot_wal_keep_size, which
means that dead catalog tuples are not removed by vacuum anymore since
the point is invalidated, until the slot is dropped. This could be
catastrophic if catalog churn is high.
Change the computation of Xmin to ignore invalidated slots,
to prevent dead rows from accumulating.
Backpatch to 13, where slot invalidation appeared.
Author: Sirisha Chamarthi <sirichamarthi22@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/CAKrAKeUEDeqquN9vwzNeG-CN8wuVsfRYbeOUV9qKO_RHok=j+g@mail.gmail.com
The lwlock wait queue scalability issue fixed in a4adc31f69 was quite hard to
find because of the exponential backoff and because we adjust spins_per_delay
over time within a backend.
To make it easier to find similar issues in the future, add a wait event for
the pg_usleep() in perform_spin_delay(). Showing a wait event while spinning
without sleeping would increase the overhead of spinlocks, which we do not
want.
We may at some later point want to have more granular wait events, but that'd
be a substantial amount of work. This provides at least some insights into
something currently hard to observe.
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com>
https://postgr.es/m/20221120204310.xywrhyxyytsajuuq@awork3.anarazel.de
We have coverage of the various sanitizers in the buildfarm. The sanitizers
however particularly interesting during the development of patches, where the
likelihood of bugs is even higher. There also have been complaints about only
seeing such failures on the buildfarm, rather than before commit.
This commit enables a reasonable set of sanitizers in CI. Use the linux task
for that, as it currently is one of the fastests tasks. Also several of the
sanitizers work best on linux.
The overhead of alignment sanitizer is low, undefined behaviour has moderate
overhead. Test alignment sanitizer in the meson task, as it does both 32 and
64 bit builds and is thus more likely to expose alignment bugs.
Address sanitizer in contrast somewhat expensive. Enable it in the autoconf
task, as the meson task tests both 32 and 64bit which would exacerbate the
cost.
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20220323173537.ll7klrglnp4gn2um@alap3.anarazel.de
Discussion: https://postgr.es/m/20221121220903.kf5u7rokfzbmqskm@alap3.anarazel.de
To avoid unnecessarily spinning up a lot of VMs / containers for entirely
broken commits, have a minimal task that all others depend on.
The concrete motivation for the change is to use sanitizers in the linux
tasks. As that makes the tests slower, the start of the CompilerWarnings would
be delayed even more. With this change the CompilerWarnings only depends on
the SanityCheck task.
This has the added advantage that now the CompilerWarnings task is not
prevented from running by (most) test failures (particularly annoying when
caused by a test that is flappy in HEAD).
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20221002205201.injtofbx4ax4erww@awork3.anarazel.de
We don't need CIRRUS_ESCAPING_PROCESSES anymore as the whole tests now run
within a single script: block. We don't need NO_TEMP_INSTALL anymore it was
addressing an issue specific to vcregress.pl.
Author: Justin Pryzby <pryzbyj@telsasoft.com>
Discussion: https://postgr.es/m/20221113235303.GA26337@telsasoft.com
The Hunspell project moved from Sourceforge to Github sometime
in 2016, so update our links to match the new URL. Backpatch
the doc changes to all supported versions.
Discussion: https://postgr.es/m/DC9A662A-360D-4125-A453-5A6CB9C6C4B4@yesql.se
Backpatch-through: v11
I just spent an annoying amount of time reverse-engineering the
100%-undocumented API between ts_headline and the text search
parser's prsheadline function. Add some commentary about that
while it's fresh in mind. Also remove some unused macros in
wparser_def.c.
While at it, I noticed that when commit 78e73e875 added a
CHECK_FOR_INTERRUPTS call in TS_execute_recurse, it missed
doing so in the parallel function TS_phrase_execute, which
surely needs one just as much.
Back-patch because of the missing CHECK_FOR_INTERRUPTS.
Might as well back-patch the rest of this too.
At least on linux, set_ps_display() breaks /proc/$pid/environ. The sanitizer's
helper library uses /proc/$pid/environ to implement getenv(), as it wants to
work independent of libc. When just using undefined and alignment sanitizers,
the sanitizer library is only initialized when the first error occurs, by
which time we've often already called set_ps_display(), preventing the
sanitizer libraries from seeing the options.
We can work around that by defining __ubsan_default_options, a weak symbol
libsanitizer uses to get defaults from the application, and return
getenv("UBSAN_OPTIONS"). But only if main already was reached, so that we
don't end up relying on a not-yet-working getenv().
As it's just a function that won't get called when not running a sanitizer, it
doesn't seem necessary to make compilation of the function conditional.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20220323173537.ll7klrglnp4gn2um@alap3.anarazel.de
These functions have been marked parallel safe, but the buildfarm's
response to commit e2933a6e1 exposed the flaw in that thinking:
if you try to use them on a temporary table, and they run inside
a parallel worker, they'll fail with "cannot access temporary tables
during a parallel operation".
Fix that by marking them parallel restricted instead. Maybe someday
we'll have a better answer and can reverse this decision.
Back-patch to v15. To go back further, we'd have to devise variant
versions of pre-1.10 pageinspect versions. Given the lack of field
complaints, it doesn't seem worth the trouble. We'll just deem
this case unsupported pre-v15. (If anyone does complain, it might
be good enough to update the markings manually in their DBs.)
Discussion: https://postgr.es/m/E1ox94a-000EHu-VH@gemulon.postgresql.org
The postmaster normally sends SIGQUIT to force-terminate its
child processes after a child crash or immediate-stop request.
If that doesn't result in child exit within a few seconds,
we follow it up with SIGKILL. This patch provides GUC flags
that allow either of these signals to be replaced with SIGABRT.
On typically-configured Unix systems, that will result in a
core dump being produced for each such child. This can be
useful for debugging problems, although it's not something you'd
want to have on in production due to the risk of disk space
bloat from lots of core files.
The old postmaster -T switch, which sent SIGSTOP in place of
SIGQUIT, is changed to be the same as send_abort_for_crash.
As far as I can tell from the code comments, the intent of
that switch was just to block things for long enough to force
core dumps manually, which seems like an unnecessary extra step.
(Maybe at the time, there was no way to get most kernels to
produce core files with per-PID names, requiring manual core
file renaming after each one. But now it's surely the hard way.)
I also took the opportunity to remove the old postmaster -n
(skip shmem reinit) switch, which hasn't actually done anything
in decades, though the documentation still claimed it did.
Discussion: https://postgr.es/m/2251016.1668797294@sss.pgh.pa.us
pageinspect has occasionally failed on slow buildfarm members,
with symptoms indicating that the expected effects of VACUUM
FREEZE didn't happen. This is presumably because a background
transaction such as auto-analyze was holding back global xmin.
We can work around that by using a temp table in the test.
Since commit a7212be8b, that will use an up-to-date cutoff xmin
regardless of other processes. And pageinspect itself shouldn't
really care whether the table is temp.
Back-patch to v14. There would be no point in older branches
without back-patching a7212be8b, which seems like more trouble
than the problem is worth.
Discussion: https://postgr.es/m/2892135.1668976646@sss.pgh.pa.us
This switch impacts 9 patterns related to a SQL-mandated special syntax
for function calls:
- LOCALTIME [ ( typmod ) ]
- LOCALTIMESTAMP [ ( typmod ) ]
- CURRENT_TIME [ ( typmod ) ]
- CURRENT_TIMESTAMP [ ( typmod ) ]
- CURRENT_DATE
Five new entries are added to pg_proc to compensate the removal of
SQLValueFunction to provide backward-compatibility and making this
change transparent for the end-user (for example for the attribute
generated when a keyword is specified in a SELECT or in a FROM clause
without an alias, or when specifying something else than an Iconst to
the parser).
The parser included a set of checks coming from the files in charge of
holding the C functions used for the SQLValueFunction calls (as of
transformSQLValueFunction()), which are now moved within each function's
execution path, so this reduces the dependencies between the execution
and the parsing steps. As of this change, all the SQL keywords use the
same paths for their work, relying only on COERCE_SQL_SYNTAX. Like
fb32748, no performance difference has been noticed, while the perf
profiles get reduced with ExecEvalSQLValueFunction() gone.
Bump catalog version.
Reviewed-by: Corey Huinker, Ted Yu
Discussion: https://postgr.es/m/YzaG3MoryCguUOym@paquier.xyz
As per one of the CI reports, there is an assertion failure which
indicates that we were trying to use an unenforced xmin horizon for
decoding snapshots. Though, we couldn't figure out the reason for
assertion failure these checks would help us in finding the reason if the
problem happens again in the future.
Author: Amit Kapila based on suggestions by Andres Freund
Reviewd by: Andres Freund
Discussion: https://postgr.es/m/CAA4eK1L8wYcyTPxNzPGkhuO52WBGoOZbT0A73Le=ZUWYAYmdfw@mail.gmail.com
Until now LWLockDequeueSelf() sequentially searched the list of waiters to see
if the current proc is still is on the list of waiters, or has already been
removed. In extreme workloads, where the wait lists are very long, this leads
to a quadratic behavior. #backends iterating over a list #backends
long. Additionally, the likelihood of needing to call LWLockDequeueSelf() in
the first place also increases with the increased length of the wait queue, as
it becomes more likely that a lock is released while waiting for the wait list
lock, which is held for longer during lock release.
Due to the exponential back-off in perform_spin_delay() this is surprisingly
hard to detect. We should make that easier, e.g. by adding a wait event around
the pg_usleep() - but that's a separate patch.
The fix is simple - track whether a proc is currently waiting in the wait list
or already removed but waiting to be woken up in PGPROC->lwWaiting.
In some workloads with a lot of clients contending for a small number of
lwlocks (e.g. WALWriteLock), the fix can substantially increase throughput.
As the quadratic behavior arguably is a bug, we might want to decide to
backpatch this fix in the future.
Author: Andres Freund <andres@anarazel.de>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Discussion: https://postgr.es/m/20221027165914.2hofzp4cvutj6gin@awork3.anarazel.de
Discussion: https://postgr.es/m/CALj2ACXktNbG=K8Xi7PSqbofTZozavhaxjatVc14iYaLu4Maag@mail.gmail.com
As the list of shared relations is fixed, we can just dispatch based
IsSharedRelation(), instead of first trying to look up stats for a non-shared
rel and falling back to shared stats.
Author: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Reviewed-by: Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de
Discussion: https://postgr.es/m/8c1851a2-a98e-e1bc-7729-37b0b95f66ec@gmail.com
Commit 3d14e171e dropped regress_roleoption_donor twice and
regress_roleoption_protagonist not at all. Leaving roles behind
after "make installcheck" is unfriendly in its own right, plus
it causes repeated runs of "make installcheck" to fail.
Commit c94959d41 fixed DROP OPERATOR to reset oprcom/oprnegate links
to the dropped operator; but it missed updating this old comment that
claimed we allow such links to dangle.
Currently there is a race condition where if concurrent TAP tests both
test that they can open a port they will assume that it is free and use
it, causing one of them to fail. To prevent this we record a reservation
using an exclusive lock, and any TAP test that discovers a reservation
checks to see if the reserving process is still alive, and looks for
another free port if it is.
Ports are reserved in a directory set by the environment setting
PG_TEST_PORT_DIR, or if that doesn't exist a subdirectory of the top
build directory as set by meson or Makefile.global, or its own
tmp_check directory.
The prove_check recipe in Makefile.global.in is extended to export
top_builddir to the TAP tests. This was already exported by the
prove_installcheck recipes.
Per complaint from Andres Freund
This will be backpatched in due course after some testing.
Discussion: https://postgr.es/m/20221002164931.d57hlutrcz4d2zi7@awork3.anarazel.de
This commit changes six SQL keywords to use COERCE_SQL_SYNTAX rather
than relying on SQLValueFunction:
- CURRENT_ROLE
- CURRENT_USER
- USER
- SESSION_USER
- CURRENT_CATALOG
- CURRENT_SCHEMA
Among the six, "user", "current_role" and "current_catalog" require
specific SQL functions to allow ruleutils.c to map them to the SQL
keywords these require when using COERCE_SQL_SYNTAX. Having
pg_proc.proname match with the keyword ensures that the compatibility
remains the same when projecting any of these keywords in a FROM clause
to an attribute name when an alias is not specified. This is covered by
the tests added in 2e0d80c, making sure that a correct mapping happens
with each SQL keyword. The three others (current_schema, session_user
and current_user) already have pg_proc entries for this job, so this
brings more consistency between the way such keywords are treated in the
parser, the executor and ruleutils.c.
SQLValueFunction is reduced to half its contents after this change,
simplifying its logic a bit as there is no need to enforce a C collation
anymore for the entries returning a name as a result. I have made a few
performance tests, with a million-ish calls to these keywords without
seeing a difference in run-time or in perf profiles
(ExecEvalSQLValueFunction() is removed from the profiles). The
remaining SQLValueFunctions are now related to timestamps and dates.
Bump catalog version.
Reviewed-by: Corey Huinker
Discussion: https://postgr.es/m/YzaG3MoryCguUOym@paquier.xyz
ProcSleep() used a PGPROC* variable to point to PROC_QUEUE->links.next,
because that does "the right thing" with SHMQueueInsertBefore(). While that
largely works, it's certainly not correct and unnecessary - we can just use
SHM_QUEUE* to point to the insertion point.
Noticed when testing a 32bit of postgres with undefined behavior
sanitizer. UBSan noticed that sometimes the supposed PGPROC wasn't
sufficiently aligned (required since 46d6e5f567, ensured indirectly, via
ShmemAllocRaw() guaranteeing cacheline alignment).
For now fix this by using a SHM_QUEUE* for the insertion point. Subsequently
we should replace all the use of PROC_QUEUE and SHM_QUEUE with ilist.h, but
that's a larger change that we don't want to backpatch.
Backpatch to all supported versions - it's useful to be able to run postgres
under UBSan.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/20221117014230.op5kmgypdv2dtqsf@awork3.anarazel.de
Backpatch: 11-
The test output varies when debug_discard_caches is enabled,
because that causes extra executions of recomputeNamespacePath.
Maybe putting a hook in that was a bad idea, but as a stopgap,
just turn off debug_discard_caches in this test.
Per buildfarm (now that we have debug_discard_caches coverage
again). Back-patch to v15 where this module was added.
Discussion: https://postgr.es/m/2267406.1668804934@sss.pgh.pa.us
basics.source is supposed to be pretty closely in step with
the examples in chapter 2 of the tutorial, but I forgot to
update it in commit f05a5e000. Fix that, and adjust a couple
of other discrepancies that had crept in over time.
(I notice that advanced.source is nowhere near being in sync
with chapter 3, but I lack the ambition to do something
about that right now.)
Similar to how the INHERIT option controls whether or not the
permissions of the granted role are automatically available to the
grantee, the new SET permission controls whether or not the grantee
may use the SET ROLE command to assume the privileges of the granted
role.
In addition, the new SET permission controls whether or not it
is possible to transfer ownership of objects to the target role
or to create new objects owned by the target role using commands
such as CREATE DATABASE .. OWNER. We could alternatively have made
this controlled by the INHERIT option, or allow it when either
option is given. An advantage of this approach is that if you
are granted a predefined role with INHERIT TRUE, SET FALSE, you
can't go and create objects owned by that role.
The underlying theory here is that the ability to create objects
as a target role is not a privilege per se, and thus does not
depend on whether you inherit the target role's privileges. However,
it's surely something you could do anyway if you could SET ROLE
to the target role, and thus making it contingent on whether you
have that ability is reasonable.
Design review by Nathan Bossat, Wolfgang Walther, Jeff Davis,
Peter Eisentraut, and Stephen Frost.
Discussion: http://postgr.es/m/CA+Tgmob+zDSRS6JXYrgq0NWdzCXuTNzT5eK54Dn2hhgt17nm8A@mail.gmail.com
eqjoinsel() currently makes use of MCV stats only when we have such
stats for both sides of the clause. As coded, though, it would
fetch those stats even when they're present for just one side.
This can be a bit expensive with high statistics targets, leading
to wasted effort in common cases such as joining a unique column
to a non-unique column. So it seems worth the trouble to do a quick
pre-check to confirm that both sides have MCVs before fetching either.
Also, tweak the API spec for get_attstatsslot() to document the
method we're using here.
David Geier, Tomas Vondra, Tom Lane
Discussion: https://postgr.es/m/b9846ca0-5f1c-9b26-5881-aad3f42b07f0@gmail.com
The object_address test file turns to psql unaligned output for some
tests to avoid huge diffs for changes. But this is useful also to the
other large test in that file, so apply it there as well. This also
makes verifying the null and whitespace behavior easier.
Version strings with unequal numbers of parts were being compared
incorrectly. We cure this by treating a missing part in the shorter
version as 0.
per complaint from Jehan-Guillaume de Rorthais, but the fix is mine, not
his.
Discussion: https://postgr.es/m/20220628225325.53d97b8d@karst
Backpatch to release 14 where this code was introduced.
This commit improves the handling of the following clauses:
- Addition of "CREATE" for ALTER DEFAULT PRIVILEGES .. GRANT/REVOKE.
- Addition of GRANT|ADMIN|INHERIT OPTION FOR for REVOKE, with some
completion for roles, INHERIT being added recently by e3ce2de.
- Addition of GRANT WITH ADMIN|INHERIT.
The list of privilege options common to GRANT and REVOKE is refactored
to avoid its duplication.
Author: Shi Yu
Reviewed-by: Kyotaro Horiguchi, Michael Paquier, Peter Smith
Discussion: https://postgr.es/m/OSZPR01MB6310FCE8609185A56344EED2FD559@OSZPR01MB6310.jpnprd01.prod.outlook.com
For now the task has been set to be manually triggered, as we are already
limited by the amount of CI time available for windows, particularly on cfbot.
Author: Melih Mutlu <m.melihmutlu@gmail.com>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: https://postgr.es/m/CAGPVpCSKS9E0An4=e7ZDnme+y=WOcQFJYJegKO8kE9=gh8NJKQ@mail.gmail.com
Standardize on the name snapshotConflictHorizon for all XID fields from
WAL records that generate recovery conflicts when in hot standby mode.
This supersedes the previous latestRemovedXid naming convention.
The new naming convention places emphasis on how the values are actually
used by REDO routines. How the values are generated during original
execution (details of which vary by record type) is deemphasized. Users
of tools like pg_waldump can now grep for snapshotConflictHorizon to see
all potential sources of recovery conflicts in a standardized way,
without necessarily having to consider which specific record types might
be involved.
Also bring a couple of WAL record types that didn't follow any kind of
naming convention into line. These are heapam's VISIBLE record type and
SP-GiST's VACUUM_REDIRECT record type. Now every WAL record whose REDO
routine calls ResolveRecoveryConflictWithSnapshot() passes through the
snapshotConflictHorizon field from its WAL record. This is follow-up
work to the refactoring from commit 9e540599 that made FREEZE_PAGE WAL
records use a standard snapshotConflictHorizon style XID cutoff.
No bump in XLOG_PAGE_MAGIC, since the underlying format of affected WAL
records doesn't change.
Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CAH2-Wzm2CQUmViUq7Opgk=McVREHSOorYaAjR1ZpLYkRN7_dPw@mail.gmail.com
Before, receiving a NegotiateProtocolVersion message would result in a
confusing error message like
expected authentication request from server, but received v
This adds proper handling of this protocol message and produces an
on-topic error message from it.
Reviewed-by: Jacob Champion <jchampion@timescale.com>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/f9c7862f-b864-8ef7-a861-c4638c83e209%40enterprisedb.com
After sending a startup message, libpq expects either an error
response ('E') or an authentication request ('R'). Before processing
the message, it ensures it has read enough bytes to correspond to the
length specified in the message. However, when processing the 'R'
message, if an EOF status is returned it loops back waiting for more
input, even though we already checked that we have enough input. In
this particular case, this is probably not reachable anyway, because
other code ensures we have enough bytes for an authentication request
message, but the code is wrong and misleading. In the more general
case, processing a faulty message could result in an EOF status, which
would then result in an infinite loop waiting for the end of a message
that will never come. The correction is to make this an error.
Reported-by: Jacob Champion <jchampion@timescale.com>
Discussion: https://www.postgresql.org/message-id/flat/f9c7862f-b864-8ef7-a861-c4638c83e209@enterprisedb.com
This commend references a struct that disappeared before MERGE was
merged ... and ExecDelete is not called by the committed MERGE anyway.
Revert to the original wording.
Backpatch to 15
Andrew Dunstan