The GRANT reference page, which lists the default privileges for new
objects, failed to mention that USAGE is granted by default for data
types and domains. As a lesser sin, it also did not specify anything
about the initial privileges for sequences, FDWs, foreign servers,
or large objects. Fix that, and add a comment to acldefault() in the
probably vain hope of getting people to maintain this list in future.
Noted by Laurenz Albe, though I editorialized on the wording a bit.
Back-patch to all supported branches, since they all have this behavior.
Discussion: https://postgr.es/m/1507620895.4152.1.camel@cybertec.at
Up to now async.c has used TransactionIdIsInProgress() to detect whether
a notify message's source transaction is still running. However, that
function has a quick-exit path that reports that XIDs before RecentXmin
are no longer running. If a listening backend is doing nothing but
listening, and not running any queries, there is nothing that will advance
its value of RecentXmin. Once 2 billion transactions elapse, the
RecentXmin check causes active transactions to be reported as not running.
If they aren't committed yet according to CLOG, async.c decides they
aborted and discards their messages. The timing for that is a bit tight
but it can happen when multiple backends are sending notifies concurrently.
The net symptom therefore is that a sufficiently-long-surviving
listen-only backend starts to miss some fraction of NOTIFY traffic,
but only under heavy load.
The only function that updates RecentXmin is GetSnapshotData().
A brute-force fix would therefore be to take a snapshot before
processing incoming notify messages. But that would add cycles,
as well as contention for the ProcArrayLock. We can be smarter:
having taken the snapshot, let's use that to check for running
XIDs, and not call TransactionIdIsInProgress() at all. In this
way we reduce the number of ProcArrayLock acquisitions from one
per message to one per notify interrupt; that's the same under
light load but should be a benefit under heavy load. Light testing
says that this change is a wash performance-wise for normal loads.
I looked around for other callers of TransactionIdIsInProgress()
that might be at similar risk, and didn't find any; all of them
are inside transactions that presumably have already taken a
snapshot.
Problem report and diagnosis by Marko Tiikkaja, patch by me.
Back-patch to all supported branches, since it's been like this
since 9.0.
Discussion: https://postgr.es/m/20170926182935.14128.65278@wrigleys.postgresql.org
copy_file() reads and writes data 64KB at a time (with default BLCKSZ),
and historically has issued a pg_flush_data request after each write.
This turns out to interact really badly with macOS's new APFS file
system: a large file copy takes over 100X longer than it ought to on
APFS, as reported by Brent Dearth. While that's arguably a macOS bug,
it's not clear whether Apple will do anything about it in the near
future, and in any case experimentation suggests that issuing flushes
a bit less often can be helpful on other platforms too.
Hence, rearrange the logic in copy_file() so that flush requests are
issued once per N writes rather than every time through the loop.
I set the FLUSH_DISTANCE to 32MB on macOS (any less than that still
results in a noticeable speed degradation on APFS), but 1MB elsewhere.
In limited testing on Linux and FreeBSD, this seems slightly faster
than the previous code, and certainly no worse. It helps noticeably
on macOS even with the older HFS filesystem.
A simpler change would have been to just increase the size of the
copy buffer without changing the loop logic, but that seems likely
to trash the processor cache without really helping much.
Back-patch to 9.6 where we introduced msync() as an implementation
option for pg_flush_data(). The problem seems specific to APFS's
mmap/msync support, so I don't think we need to go further back.
Discussion: https://postgr.es/m/CADkxhTNv-j2jw2g8H57deMeAbfRgYBoLmVuXkC=YCFBXRuCOww@mail.gmail.com
The logical decoding functions do BeginInternalSubTransaction and
RollbackAndReleaseCurrentSubTransaction to clean up after themselves.
It turns out that AtEOSubXact_SPI has an unrecognized assumption that
we always need to cancel the active SPI operation in the SPI context
that surrounds the subtransaction (if there is one). That's true
when the RollbackAndReleaseCurrentSubTransaction call is coming from
the SPI-using function itself, but not when it's happening inside
some unrelated function invoked by a SPI query. In practice the
affected callers are the various PLs.
To fix, record the current subtransaction ID when we begin a SPI
operation, and clean up only if that ID is the subtransaction being
canceled.
Also, remove AtEOSubXact_SPI's assertion that it must have cleaned
up the surrounding SPI context's active tuptable. That's proven
wrong by the same test case.
Also clarify (or, if you prefer, reinterpret) the calling conventions
for _SPI_begin_call and _SPI_end_call. The memory context cleanup
in the latter means that these have always had the flavor of a matched
resource-management pair, but they weren't documented that way before.
Per report from Ben Chobot.
Back-patch to 9.4 where logical decoding came in. In principle,
the SPI changes should go all the way back, since the problem dates
back to commit 7ec1c5a86. But given the lack of field complaints
it seems few people are using internal subtransactions in this way.
So I don't feel a need to take any risks in 9.2/9.3.
Discussion: https://postgr.es/m/73FBA179-C68C-4540-9473-71E865408B15@silentmedia.com
Sloppy loop coding in set_status_by_pages() resulted in fetching one array
element more than it should from the subxids[] array. The odds of this
resulting in SIGSEGV are pretty small, but we've certainly seen that happen
with similar mistakes elsewhere. While at it, we can get rid of an extra
TransactionIdToPage() calculation per loop.
Per report from David Binderman. Back-patch to all supported branches,
since this code is quite old.
Discussion: https://postgr.es/m/HE1PR0802MB2331CBA919CBFFF0C465EB429C710@HE1PR0802MB2331.eurprd08.prod.outlook.com
When some tuple versions in an update chain are frozen due to them being
older than freeze_min_age, the xmax/xmin trail can become broken. This
breaks HOT (and probably other things). A subsequent VACUUM can break
things in more serious ways, such as leaving orphan heap-only tuples
whose root HOT redirect items were removed. This can be seen because
index creation (or REINDEX) complain like
ERROR: XX000: failed to find parent tuple for heap-only tuple at (0,7) in table "t"
Because of relfrozenxid contraints, we cannot avoid the freezing of the
early tuples, so we must cope with the results: whenever we see an Xmin
of FrozenTransactionId, consider it a match for whatever the previous
Xmax value was.
This problem seems to have appeared in 9.3 with multixact changes,
though strictly speaking it seems unrelated.
Since 9.4 we have commit 37484ad2a "Change the way we mark tuples as
frozen", so the fix is simple: just compare the raw Xmin (still stored
in the tuple header, since freezing merely set an infomask bit) to the
Xmax. But in 9.3 we rewrite the Xmin value to FrozenTransactionId, so
the original value is lost and we have nothing to compare the Xmax with.
To cope with that case we need to compare the Xmin with FrozenXid,
assume it's a match, and hope for the best. Sadly, since you can
pg_upgrade a 9.3 instance containing half-frozen pages to newer
releases, we need to keep the old check in newer versions too, which
seems a bit brittle; I hope we can somehow get rid of that.
I didn't optimize the new function for performance. The new coding is
probably a bit slower than before, since there is a function call rather
than a straight comparison, but I'd rather have it work correctly than
be fast but wrong.
This is a followup after 20b6552242 fixed a few related problems.
Apparently, in 9.6 and up there are more ways to get into trouble, but
in 9.3 - 9.5 I cannot reproduce a problem anymore with this patch, so
there must be a separate bug.
Reported-by: Peter Geoghegan
Diagnosed-by: Peter Geoghegan, Michael Paquier, Daniel Wood,
Yi Wen Wong, Álvaro
Discussion: https://postgr.es/m/CAH2-Wznm4rCrhFAiwKPWTpEw2bXDtgROZK7jWWGucXeH3D1fmA@mail.gmail.com
1. Since commit b1a9bad9e7 we had pstrdup() inside a
spinlock-protected critical section; reported by Andreas Seltenreich.
Turn those into strlcpy() to stack-allocated variables instead.
Backpatch to 9.6.
2. Since commit 9ed551e0a4 we had a pfree() uselessly inside a
spinlock-protected critical section. Tom Lane noticed in code review.
Move down. Backpatch to 9.6.
3. Since commit 64233902d2 we had GetCurrentTimestamp() (a kernel
call) inside a spinlock-protected critical section. Tom Lane noticed in
code review. Move it up. Backpatch to 9.2.
4. Since commit 1bb2558046 we did elog(PANIC) while holding spinlock.
Tom Lane noticed in code review. Release spinlock before dying.
Backpatch to 9.2.
Discussion: https://postgr.es/m/87h8vhtgj2.fsf@ansel.ydns.eu
Buildfarm members skink and sungazer have both recently failed this
test, with symptoms indicating that the default 3-second timeout
isn't quite enough for those very slow systems. There's no reason
to be miserly with this timeout, so boost it to 60 seconds.
Back-patch to all versions containing this test. That may be overkill,
because the failure has only been observed in the v10 branch, but
I don't feel like having to revisit this later.
Vacuum calls page-level HOT prune to remove dead HOT tuples before doing
liveness checks (HeapTupleSatisfiesVacuum) on the remaining tuples. But
concurrent transaction commit/abort may turn DEAD some of the HOT tuples
that survived the prune, before HeapTupleSatisfiesVacuum tests them.
This happens to activate the code that decides to freeze the tuple ...
which resuscitates it, duplicating data.
(This is especially bad if there's any unique constraints, because those
are now internally violated due to the duplicate entries, though you
won't know until you try to REINDEX or dump/restore the table.)
One possible fix would be to simply skip doing anything to the tuple,
and hope that the next HOT prune would remove it. But there is a
problem: if the tuple is older than freeze horizon, this would leave an
unfrozen XID behind, and if no HOT prune happens to clean it up before
the containing pg_clog segment is truncated away, it'd later cause an
error when the XID is looked up.
Fix the problem by having the tuple freezing routines cope with the
situation: don't freeze the tuple (and keep it dead). In the cases that
the XID is older than the freeze age, set the HEAP_XMAX_COMMITTED flag
so that there is no need to look up the XID in pg_clog later on.
An isolation test is included, authored by Michael Paquier, loosely
based on Daniel Wood's original reproducer. It only tests one
particular scenario, though, not all the possible ways for this problem
to surface; it be good to have a more reliable way to test this more
fully, but it'd require more work.
In message https://postgr.es/m/20170911140103.5akxptyrwgpc25bw@alvherre.pgsql
I outlined another test case (more closely matching Dan Wood's) that
exposed a few more ways for the problem to occur.
Backpatch all the way back to 9.3, where this problem was introduced by
multixact juggling. In branches 9.3 and 9.4, this includes a backpatch
of commit e5ff9fefcd50 (of 9.5 era), since the original is not
correctable without matching the coding pattern in 9.5 up.
Reported-by: Daniel Wood
Diagnosed-by: Daniel Wood
Reviewed-by: Yi Wen Wong, Michaël Paquier
Discussion: https://postgr.es/m/E5711E62-8FDF-4DCA-A888-C200BF6B5742@amazon.com
float8_numeric() and float4_numeric() failed to consider the possibility
that the input is an IEEE infinity. The results depended on the
platform-specific behavior of sprintf(): on most platforms you'd get
something like
ERROR: invalid input syntax for type numeric: "inf"
but at least on Windows it's possible for the conversion to succeed and
deliver a finite value (typically 1), due to a nonstandard output format
from sprintf and lack of syntax error checking in these functions.
Since our numeric type lacks the concept of infinity, a suitable conversion
is impossible; the best thing to do is throw an explicit error before
letting sprintf do its thing.
While at it, let's use snprintf not sprintf. Overrunning the buffer
should be impossible if sprintf does what it's supposed to, but this
is cheap insurance against a stack smash if it doesn't.
Problem reported by Taiki Kondo. Patch by me based on fix suggestion
from KaiGai Kohei. Back-patch to all supported branches.
Discussion: https://postgr.es/m/12A9442FBAE80D4E8953883E0B84E088C8C7A2@BPXM01GP.gisp.nec.co.jp
posix_fallocate() is not quite a drop-in replacement for fallocate(),
because it is defined to return the error code as its function result,
not in "errno". I (tgl) missed this because RHEL6's version seems
to set errno as well. That is not the case on more modern Linuxen,
though, as per buildfarm results.
Aside from fixing the return-convention confusion, remove the test
for ENOSYS; we expect that glibc will mask that for posix_fallocate,
though it does not for fallocate. Keep the test for EINTR, because
POSIX specifies that as a possible result, and buildfarm results
suggest that it can happen in practice.
Back-patch to 9.4, like the previous commit.
Thomas Munro
Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
On Linux, shared memory segments created with shm_open() are backed by
swap files created in tmpfs. If the swap file needs to be extended,
but there's no tmpfs space left, you get a very unfriendly SIGBUS trap.
To avoid this, force allocation of the full request size when we create
the segment. This adds a few cycles, but none that we wouldn't expend
later anyway, assuming the request isn't hugely bigger than the actual
need.
Make this code #ifdef __linux__, because (a) there's not currently a
reason to think the same problem exists on other platforms, and (b)
applying posix_fallocate() to an FD created by shm_open() isn't very
portable anyway.
Back-patch to 9.4 where the DSM code came in.
Thomas Munro, per a bug report from Amul Sul
Discussion: https://postgr.es/m/1002664500.12301802.1471008223422.JavaMail.yahoo@mail.yahoo.com
In two cases, we set a different umask for some piece of code and
restore it afterwards. But if the contained code errors out, the umask
is not restored. So add TRY/CATCH blocks to fix that.
This patch absorbs a few unreleased fixes in the IANA code.
It corresponds to commit 2d8b944c1cec0808ac4f7a9ee1a463c28f9cd00a
in https://github.com/eggert/tz. Non-cosmetic changes include:
TZDEFRULESTRING is updated to match current US DST practice,
rather than what it was over ten years ago. This only matters
for interpretation of POSIX-style zone names (e.g., "EST5EDT"),
and only if the timezone database doesn't include either an exact
match for the zone name or a "posixrules" entry. The latter
should not be true in any current Postgres installation, but
this could possibly matter when using --with-system-tzdata.
Get rid of a nonportable use of "++var" on a bool var.
This is part of a larger fix that eliminates some vestigial
support for consecutive leap seconds, and adds checks to
the "zic" compiler that the data files do not specify that.
Remove a couple of ancient compatibility hacks. The IANA
crew think these are obsolete, and I tend to agree. But
perhaps our buildfarm will think different.
Back-patch to all supported branches, in line with our policy
that all branches should be using current IANA code. Before v10,
this includes application of current pgindent rules, to avoid
whitespace problems in future back-patches.
Discussion: https://postgr.es/m/E1dsWhf-0000pT-F9@gemulon.postgresql.org
Previously, the code didn't think about this case and would just try to
analyze such a column twice. That would fail at the point of inserting
the second version of the pg_statistic row, with obscure error messsages
like "duplicate key value violates unique constraint" or "tuple already
updated by self", depending on context and PG version. We could allow
the case by ignoring duplicate column specifications, but it seems better
to reject it explicitly.
The bogus error messages seem like arguably a bug, so back-patch to
all supported versions.
Nathan Bossart, per a report from Michael Paquier, and whacked
around a bit by me.
Discussion: https://postgr.es/m/E061A8E3-5E3D-494D-94F0-E8A9B312BBFC@amazon.com
AfterTriggerEndQuery correctly notes that the query_stack could get
repalloc'd during a trigger firing, but it nonetheless passes the address
of a query_stack entry to afterTriggerInvokeEvents, so that if such a
repalloc occurs, afterTriggerInvokeEvents is already working with an
obsolete dangling pointer while it scans the rest of the events. Oops.
The only code at risk is its "delete_ok" cleanup code, so we can
prevent unsafe behavior by passing delete_ok = false instead of true.
However, that could have a significant performance penalty, because the
point of passing delete_ok = true is to not have to re-scan possibly
a large number of dead trigger events on the next time through the loop.
There's more than one way to skin that cat, though. What we can do is
delete all the "chunks" in the event list except the last one, since
we know all events in them must be dead. Deleting the chunks is work
we'd have had to do later in AfterTriggerEndQuery anyway, and it ends
up saving rescanning of just about the same events we'd have gotten
rid of with delete_ok = true.
In v10 and HEAD, we also have to be careful to mop up any per-table
after_trig_events pointers that would become dangling. This is slightly
annoying, but I don't think that normal use-cases will traverse this code
path often enough for it to be a performance problem.
It's pretty hard to hit this in practice because of the unlikelihood
of the query_stack getting resized at just the wrong time. Nonetheless,
it's definitely a live bug of ancient standing, so back-patch to all
supported branches.
Discussion: https://postgr.es/m/2891.1505419542@sss.pgh.pa.us
The order in which GRANTs are output is important as GRANTs which have
been GRANT'd by individuals via WITH GRANT OPTION GRANTs have to come
after the GRANT which included the WITH GRANT OPTION. This happens
naturally in the backend during normal operation as we only change
existing ACLs in-place, only add new ACLs to the end, and when removing
an ACL we remove any which depend on it also.
Also, adjust the comments in acl.h to make this clear.
Unfortunately, the updates to pg_dump to handle initial privileges
involved pulling apart ACLs and then combining them back together and
could end up putting them back together in an invalid order, leading to
dumps which wouldn't restore.
Fix this by adjusting the queries used by pg_dump to ensure that the
ACLs are rebuilt in the same order in which they were originally.
Back-patch to 9.6 where the changes for initial privileges were done.
When copying from an active database tree, it's possible for files to be
deleted after we see them in a readdir() scan but before we can open them.
(Once we've got a file open, we don't expect any further errors from it
getting unlinked, though.) Tweak RecursiveCopy so it can cope with this
case, so as to avoid irreproducible test failures.
Back-patch to 9.6 where this code was added. In v10 and HEAD, also
remove unused "use RecursiveCopy" in one recovery test script.
Michael Paquier and Tom Lane
Discussion: https://postgr.es/m/24621.1504924323@sss.pgh.pa.us
In commit 9d6b160d7, I tweaked pg_config.h.win32 to use
"#define HAVE_LONG_LONG_INT_64 1" rather than defining it as empty,
for consistency with what happens in an autoconf'd build.
But Solution.pm injects another definition of that macro into
ecpg_config.h, leading to justifiable (though harmless) compiler whining.
Make that one consistent too. Back-patch, like the previous patch.
Discussion: https://postgr.es/m/CAEepm=1dWsXROuSbRg8PbKLh0S=8Ou-V8sr05DxmJOF5chBxqQ@mail.gmail.com
Instead of using a cast to force the constant to be the right width,
assume we can plaster on an L, UL, LL, or ULL suffix as appropriate.
The old approach to this is very hoary, dating from before we were
willing to require compilers to have working int64 types.
This fix makes the PG_INT64_MIN, PG_INT64_MAX, and PG_UINT64_MAX
constants safe to use in preprocessor conditions, where a cast
doesn't work. Other symbolic constants that might be defined using
[U]INT64CONST are likewise safer than before.
Also fix the SIZE_MAX macro to be similarly safe, if we are forced
to provide a definition for that. The test added in commit 2e70d6b5e
happens to do what we want even with the hack "(size_t) -1" definition,
but we could easily get burnt on other tests in future.
Back-patch to all supported branches, like the previous commits.
Discussion: https://postgr.es/m/15883.1504278595@sss.pgh.pa.us
Pre-C99 platforms may lack <stdint.h> and thereby SIZE_MAX. We have
a couple of places using the hack "(size_t) -1" as a fallback, but
it wasn't universally available; which means the code added in commit
2e70d6b5e fails to compile everywhere. Move that hack to c.h so that
we can rely on having SIZE_MAX everywhere.
Per discussion, it'd be a good idea to make the macro's value safe
for use in #if-tests, but that will take a bit more work. This is
just a quick expedient to get the buildfarm green again.
Back-patch to all supported branches, like the previous commit.
Discussion: https://postgr.es/m/15883.1504278595@sss.pgh.pa.us
Adding more than 1 billion rows to a PGresult would overflow its ntups and
tupArrSize fields, leading to client crashes. It'd be desirable to use
wider fields on 64-bit machines, but because all of libpq's external APIs
use plain "int" for row counters, that's going to be hard to accomplish
without an ABI break. Given the lack of complaints so far, and the general
pain that would be involved in using such huge PGresults, let's settle for
just preventing the overflow and reporting a useful error message if it
does happen. Also, for a couple more lines of code we can increase the
threshold of trouble from INT_MAX/2 to INT_MAX rows.
To do that, refactor pqAddTuple() to allow returning an error message that
replaces the default assumption that it failed because of out-of-memory.
Along the way, fix PQsetvalue() so that it reports all failures via
pqInternalNotice(). It already did so in the case of bad field number,
but neglected to report anything for other error causes.
Because of the potential for crashes, this seems like a back-patchable
bug fix, despite the lack of field reports.
Michael Paquier, per a complaint from Igor Korot.
Discussion: https://postgr.es/m/CA+FnnTxyLWyjY1goewmJNxC==HQCCF4fKkoCTa9qR36oRAHDPw@mail.gmail.com
2cd7084524 / c6293249d change the way individual attributes in a
TupleDesc are stored / accessed. To reduce the effort of making
extensions compatible with postgresql 11, and to ease future
backpatching, backpatch introduction of TupleDescAttr() to all
releases. Do not backpatch change in storage, as that'd be a breaking
change for existing and working extensions.
Author: Andres Freund
Discussion: https://postgr.es/m/20170820181723.tdswdinzptbcwhrr@alap3.anarazel.de
Backpatch: 9.2-
Commit 3eb9a5e7c unintentionally introduced an ordering dependency
into restore_toc_entries_prefork(). The existing coding of
reduce_dependencies() contains a check to skip moving a TOC entry
to the ready_list if it wasn't initially in the pending_list.
This used to suffice to prevent reduce_dependencies() from trying to
move anything into the ready_list during restore_toc_entries_prefork(),
because the pending_list stayed empty throughout that phase; but it no
longer does. The problem doesn't manifest unless the TOC has been
reordered by SortTocFromFile, which is how I missed it in testing.
To fix, just add a test for ready_list == NULL, converting the call
with NULL from a poor man's sanity check into an explicit command
not to touch TOC items' list membership. Clarify some of the comments
around this; in particular, note the primary purpose of the check for
pending_list membership, which is to ensure that we can't try to restore
the same item twice, in case a TOC list forces it to be restored before
its dependency count goes to zero.
Per report from Fabrízio de Royes Mello. Back-patch to 9.3, like the
previous commit.
Discussion: https://postgr.es/m/CAFcNs+pjuv0JL_x4+=71TPUPjdLHOXA4YfT32myj_OrrZb4ohA@mail.gmail.com
It now emerges that we can only rely on Perl to tell us we must use
-D_USE_32BIT_TIME_T if it's Perl 5.13.4 or later. For older versions,
revert to our previous practice of assuming we need that symbol in
all 32-bit Windows builds. This is not ideal, but inquiring into
which compiler version Perl was built with seems far too fragile.
In any case, we had not previously had complaints about these old
Perl versions, so let's assume this is Good Enough. (It's still
better than the situation ante commit 5a5c2feca, in that at least
the effects are confined to PL/Perl rather than the whole PG build.)
Back-patch to all supported versions, like 5a5c2feca and predecessors.
Discussion: https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com
Although not confirmed and probably rare, if the newly allocated memory
is not already zero, this could possibly have caused some problems.
Also reorder the initializations slightly so they match the order of the
struct definition.
Author: Wong, Yi Wen <yiwong@amazon.com>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
This appears to have been an omission in the original commit
0d692a0dc9. All related information_schema views already include
foreign tables.
Reported-by: Nicolas Thauvin <nicolas.thauvin@dalibo.com>
Stress testing by Andreas Seltenreich disclosed longstanding problems that
occur if a FATAL exit (e.g. due to receipt of SIGTERM) occurs while we are
trying to execute a ROLLBACK of an already-failed transaction. In such a
case, xact.c is in TBLOCK_ABORT state, so that AbortOutOfAnyTransaction
would skip AbortTransaction and go straight to CleanupTransaction. This
led to an assert failure in an assert-enabled build (due to the ROLLBACK's
portal still having a cleanup hook) or without assertions, to a FATAL exit
complaining about "cannot drop active portal". The latter's not
disastrous, perhaps, but it's messy enough to want to improve it.
We don't really want to run all of AbortTransaction in this code path.
The minimum required to clean up the open portal safely is to do
AtAbort_Memory and AtAbort_Portals. It seems like a good idea to
do AtAbort_Memory unconditionally, to be entirely sure that we are
starting with a safe CurrentMemoryContext. That means that if the
main loop in AbortOutOfAnyTransaction does nothing, we need an extra
step at the bottom to restore CurrentMemoryContext = TopMemoryContext,
which I chose to do by invoking AtCleanup_Memory. This'll result in
calling AtCleanup_Memory twice in many of the paths through this function,
but that seems harmless and reasonably inexpensive.
The original motivation for the assertion in AtCleanup_Portals was that
we wanted to be sure that any user-defined code executed as a consequence
of the cleanup hook runs during AbortTransaction not CleanupTransaction.
That still seems like a valid concern, and now that we've seen one case
of the assertion firing --- which means that exactly that would have
happened in a production build --- let's replace the Assert with a runtime
check. If we see the cleanup hook still set, we'll emit a WARNING and
just drop the hook unexecuted.
This has been like this a long time, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/877ey7bmun.fsf@ansel.ydns.eu
Commit 3c163a7fc's original choice to ignore all #define symbols whose
names begin with underscore turns out to be too simplistic. On Windows,
some Perl installations are built with -D_USE_32BIT_TIME_T, and we must
absorb that or we get the wrong result for sizeof(PerlInterpreter).
This effectively re-reverts commit ef58b87df, which injected that symbol
in a hacky way, making it apply to all of Postgres not just PL/Perl.
More significantly, it did so on *all* 32-bit Windows builds, even when
the Perl build to be used did not select this option; so that it fails
to work properly with some newer Perl builds.
By making this change, we would be introducing an ABI break in 32-bit
Windows builds; but fortunately we have not used type time_t in any
exported Postgres APIs in a long time. So it should be OK, both for
PL/Perl itself and for third-party extensions, if an extension library
is built with a different _USE_32BIT_TIME_T setting than the core code.
Patch by me, based on research by Ashutosh Sharma and Robert Haas.
Back-patch to all supported branches, as commit 3c163a7fc was.
Discussion: https://postgr.es/m/CANFyU97OVQ3+Mzfmt3MhuUm5NwPU=-FtbNH5Eb7nZL9ua8=rcA@mail.gmail.com
The sole useful effect of this function, to check that no catcache
entries have positive refcounts at transaction end, has really been
obsolete since we introduced ResourceOwners in PG 8.1. We reduced the
checks to assertions years ago, so that the function was a complete
no-op in production builds. There have been previous discussions about
removing it entirely, but consensus up to now was that it had some small
value as a cross-check for bugs in the ResourceOwner logic.
However, it now emerges that it's possible to trigger these assertions
if you hit an assert-enabled backend with SIGTERM during a call to
SearchCatCacheList, because that function temporarily increases the
refcounts of entries it's intending to add to a catcache list construct.
In a normal ERROR scenario, the extra refcounts are cleaned up by
SearchCatCacheList's PG_CATCH block; but in a FATAL exit we do a
transaction abort and exit without ever executing PG_CATCH handlers.
There's a case to be made that this is a generic hazard and we should
consider restructuring elog(FATAL) handling so that pending PG_CATCH
handlers do get run. That's pretty scary though: it could easily create
more problems than it solves. Preliminary stress testing by Andreas
Seltenreich suggests that there are not many live problems of this ilk,
so we rejected that idea.
There are more-localized ways to fix the problem; the most principled
one would be to use PG_ENSURE_ERROR_CLEANUP instead of plain PG_TRY.
But adding cycles to SearchCatCacheList isn't very appealing. We could
also weaken the assertions in AtEOXact_CatCache in some more or less
ad-hoc way, but that just makes its raison d'etre even less compelling.
In the end, the most reasonable solution seems to be to just remove
AtEOXact_CatCache altogether, on the grounds that it's not worth trying
to fix it. It hasn't found any bugs for us in many years.
Per report from Jeevan Chalke. Back-patch to all supported branches.
Discussion: https://postgr.es/m/CAM2+6=VEE30YtRQCZX7_sCFsEpoUkFBV1gZazL70fqLn8rcvBA@mail.gmail.com
find_composite_type_dependencies correctly found columns that are of
the specified type, and columns that are of arrays of that type, but
not columns that are domains or ranges over the given type, its array
type, etc. The most general way to handle this seems to be to assume
that any type that is directly dependent on the specified type can be
treated as a container type, and processed recursively (allowing us
to handle nested cases such as ranges over domains over arrays ...).
Since a type's array type already has such a dependency, we can drop
the existing special case for the array type.
The very similar logic in get_rels_with_domain was likewise a few
bricks shy of a load, as it supposed that a directly dependent type
could *only* be a sub-domain. This is already wrong for ranges over
domains, and it'll someday be wrong for arrays over domains.
Add test cases illustrating the problems, and back-patch to all
supported branches.
Discussion: https://postgr.es/m/15268.1502309024@sss.pgh.pa.us
Commit 1efc7e538 did a poor job of emulating existing logic for touching
Datums that might be expanded-object pointers. It didn't check for typlen
being -1 first, which meant it could crash on fixed-length pass-by-ref
values, and probably on cstring values as well. It also didn't use
DatumGetPointer before VARATT_IS_EXTERNAL_EXPANDED, which while currently
harmless is not according to documentation nor prevailing style.
I also think the lack of any explanation as to why datumSerialize makes
these particular nonobvious choices is pretty awful, so fix that.
Per report from Jarred Ward. Back-patch to 9.6 where this code came in.
Discussion: https://postgr.es/m/6F61E6D2-2F5E-4794-9479-A429BE1CEA4B@simple.com
Tom Lane