be part of multixacts, so allocate a slot for each prepared transaction in
the "oldest member" array in multixact.c. On PREPARE TRANSACTION, transfer
the oldest member value from the current backends slot to the prepared xact
slot. Also save and recover the value from the 2pc state file.
The symptom of the bug was that after a transaction prepared, a shared lock
still held by the prepared transaction was sometimes ignored by other
transactions.
Fix back to 8.1, where both 2PC and multixact were introduced.
output filename if CSV logging was enabled and only one of the two possible
output files got rotated during a particular call (which would, in fact,
typically be the case during a size-based rotation). This would amount to
about MAXPGPATH (1KB) per rotation, and it's been there since the CSV
code was put in, so it's surprising that nobody noticed it before.
Per bug #5196 from Thomas Poindessous.
mainloop.c. This ensures that postgres_fe.h is read before including
any system headers, which is necessary to avoid problems on some platforms
where we make nondefault selections of feature macros for stdio.h or
other headers. We have had this policy for flex modules in the backend
for many years, but for some reason it was not applied to psql.
Per trouble report from Alexandra Roy and diagnosis by Albe Laurenz.
In VACUUM FULL, an interrupt after the initial transaction has been recorded
as committed can cause postmaster to restart with the following error message:
PANIC: cannot abort transaction NNNN, it was already committed
This problem has been reported many times.
In lazy VACUUM, an interrupt after the table has been truncated by
lazy_truncate_heap causes other backends' relcache to still point to the
removed pages; this can cause future INSERT and UPDATE queries to error out
with the following error message:
could not read block XX of relation 1663/NNN/MMMM: read only 0 of 8192 bytes
The window to this race condition is extremely narrow, but it has been seen in
the wild involving a cancelled autovacuum process.
The solution for both problems is to inhibit interrupts in both operations
until after the respective transactions have been committed. It's not a
complete solution, because the transaction could theoretically be aborted by
some other error, but at least fixes the most common causes of both problems.
In PLy_output(), when the elog() call in the TRY branch throws an exception
(this can happen when a statement timeout kicks in, for example), the
PyErr_SetString() call in the CATCH branch can cause a segfault, because the
Py_XDECREF(so) call before it releases memory that is still used by the sv
variable that PyErr_SetString() uses as argument, because sv points into
memory owned by so.
Backpatched back to 8.0, where this code was introduced.
I also threw in a couple of volatile declarations for variables that are used
before and after the TRY. I don't think they caused the crash that I
observed, but they could become issues.
The original coding ensured nbuckets and nbatch didn't exceed INT_MAX,
which while not insane on its own terms did nothing to protect subsequent
code like "palloc(nbatch * sizeof(BufFile *))". Since enormous join size
estimates might well be planner error rather than reality, it seems best
to constrain the initial sizes to be not more than work_mem/sizeof(pointer),
thus ensuring the allocated arrays don't exceed work_mem. We will allow
nbatch to get bigger than that during subsequent ExecHashIncreaseNumBatches
calls, but we should still guard against integer overflow in those palloc
requests. Per bug #5145 from Bernt Marius Johnsen.
Although the given test case only seems to fail back to 8.2, previous
releases have variants of this issue, so patch all supported branches.
that it's called within an AfterTriggerBeginQuery/AfterTriggerEndQuery pair.
The RI cascade triggers suppress that overhead on the assumption that they
are always run non-deferred, so it's possible to violate the condition if
someone mistakenly changes pg_trigger to mark such a trigger deferred.
We don't really care about supporting that, but throwing an error instead
of crashing seems desirable. Per report from Marcelo Costa.
pam_message array contains exactly one PAM_PROMPT_ECHO_OFF message.
Instead, deal with however many messages there are, and don't throw error
for PAM_ERROR_MSG and PAM_TEXT_INFO messages. This logic is borrowed from
openssh 5.2p1, which hopefully has seen more real-world PAM usage than we
have. Per bug #5121 from Ryan Douglas, which turned out to be caused by
the conv_proc being called with zero messages. Apparently that is normal
behavior given the combination of Linux pam_krb5 with MS Active Directory
as the domain controller.
Patch all the way back, since this code has been essentially untouched
since 7.4. (Surprising we've not heard complaints before.)
and SSPI athentication methods. While the old 2000 byte limit was more than
enough for Unix Kerberos implementations, tickets issued by Windows Domain
Controllers can be much larger.
Ian Turner
in CREATE OR REPLACE FUNCTION. The original code would update pg_shdepend
as if a new function was being created, even if it wasn't, with two bad
consequences: pg_shdepend might record the wrong owner for the function,
and any dependencies for roles mentioned in the function's ACL would be lost.
The fix is very easy: just don't touch pg_shdepend at all when doing a
function replacement.
Also update the CREATE FUNCTION reference page, which never explained
exactly what changes and doesn't change in a function replacement.
In passing, fix the CREATE VIEW reference page similarly; there's no
code bug there, but the docs didn't say what happens.
The original coding correctly noted that these aren't just redundancies
(they're effectively X IS NOT NULL, assuming = is strict). However, they
got treated that way if X happened to be in a single-member EquivalenceClass
already, which could happen if there was an ORDER BY X clause, for instance.
The simplest and most reliable solution seems to be to not try to process
such clauses through the EquivalenceClass machinery; just throw them back
for traditional processing. The amount of work that'd be needed to be
smarter than that seems out of proportion to the benefit.
Per bug #5084 from Bernt Marius Johnsen, and analysis by Andrew Gierth.
possibility of shared-inval messages causing a relcache flush while it tries
to fill in missing data in preloaded relcache entries. There are actually
two distinct failure modes here:
1. The flush could delete the next-to-be-processed cache entry, causing
the subsequent hash_seq_search calls to go off into the weeds. This is
the problem reported by Michael Brown, and I believe it also accounts
for bug #5074. The simplest fix is to restart the hashtable scan after
we've read any new data from the catalogs. It appears that pre-8.4
branches have not suffered from this failure, because by chance there were
no other catalogs sharing the same hash chains with the catalogs that
RelationCacheInitializePhase2 had work to do for. However that's obviously
pretty fragile, and it seems possible that derivative versions with
additional system catalogs might be vulnerable, so I'm back-patching this
part of the fix anyway.
2. The flush could delete the *current* cache entry, in which case the
pointer to the newly-loaded data would end up being stored into an
already-deleted Relation struct. As long as it was still deleted, the only
consequence would be some leaked space in CacheMemoryContext. But it seems
possible that the Relation struct could already have been recycled, in
which case this represents a hard-to-reproduce clobber of cached data
structures, with unforeseeable consequences. The fix here is to pin the
entry while we work on it.
In passing, also change RelationCacheInitializePhase2 to Assert that
formrdesc() set up the relation's cached TupleDesc (rd_att) with the
correct type OID and hasoids values. This is more appropriate than
silently updating the values, because the original tupdesc might already
have been copied into the catcache. However this part of the patch is
not in HEAD because it fails due to some questionable recent changes in
formrdesc :-(. That will be cleaned up in a subsequent patch.
of checkpoint. Although the checkpoint has been written to WAL at that point
already, so that all data is safe, and we'll retry removing the WAL segment at
the next checkpoint, if such a failure persists we won't be able to remove any
other old WAL segments either and will eventually run out of disk space. It's
better to treat the failure as non-fatal, and move on to clean any other WAL
segment and continue with any other end-of-checkpoint cleanup.
We don't normally expect any such failures, but on Windows it can happen with
some anti-virus or backup software that lock files without FILE_SHARE_DELETE
flag.
Also, the loop in pgrename() to retry when the file is locked was broken. If a
file is locked on Windows, you get ERROR_SHARE_VIOLATION, not
ERROR_ACCESS_DENIED, at least on modern versions. Fix that, although I left
the check for ERROR_ACCESS_DENIED in there as well (presumably it was correct
in some environment), and added ERROR_LOCK_VIOLATION to be consistent with
similar checks in pgwin32_open(). Reduce the timeout on the loop from 30s to
10s, on the grounds that since it's been broken, we've effectively had a
timeout of 0s and no-one has complained, so a smaller timeout is actually
closer to the old behavior. A longer timeout would mean that if recycling a
WAL file fails because it's locked for some reason, InstallXLogFileSegment()
will hold ControlFileLock for longer, potentially blocking other backends, so
a long timeout isn't totally harmless.
While we're at it, set errno correctly in pgrename().
Backpatch to 8.2, which is the oldest version supported on Windows. The xlog.c
changes would make sense on other platforms and thus on older versions as
well, but since there's no such locking issues on other platforms, it's not
worth it.
file handle on it, the file goes into "pending deletion" state where it
still shows up in directory listing, but isn't accessible otherwise. That
confuses RemoveOldXLogFiles(), making it think that the file hasn't been
archived yet, while it actually was, and it was deleted along with the .done
file.
Fix that by renaming the file with ".deleted" extension before deleting it.
Also check the return value of rename() and unlink(), so that if the removal
fails for any reason (e.g another process is holding the file locked), we
don't delete the .done file until the WAL file is really gone.
Backpatch to 8.2, which is the oldest version supported on Windows.
It seems the flex developers have decided to change yyleng from int to size_t.
This has already happened in the latest release of OS X, and will start
happening elsewhere once the next release of flex appears. Rather than trying
to divine how it's declared in any particular build, let's just remove the one
existing not-very-necessary external usage.
Back-patch to all supported branches; not so much because users in the field
are likely to care about building old branches with cutting-edge flex, as
to keep OSX-based buildfarm members from having problems with old branches.
to the Default timezone abbreviation set.
Back-port the the current file set to all branches that contain tznames.
This includes adding SGT to the Default set in pre-8.4 releases.
Joachim Wieland
specify an encoding explicitly, we used to treat it as being in database
encoding when we parsed it, but then perform a UTF-8 -> database encoding
conversion on it, which was completely bogus. It's now consistently treated as
UTF-8.
to unload and re-load the library.
The difficulty with unloading a library is that we haven't defined safe
protocols for doing so. In particular, there's no safe mechanism for
getting out of a "hook" function pointer unless libraries are unloaded
in reverse order of loading. And there's no mechanism at all for undefining
a custom GUC variable, so GUC would be left with a pointer to an old value
that might or might not still be valid, and very possibly wouldn't be in
the same place anymore.
While the unload and reload behavior had some usefulness in easing
development of new loadable libraries, it's of no use whatever to normal
users, so just disabling it isn't giving up that much. Someday we might
care to expend the effort to develop safe unload protocols; but even if
we did, there'd be little certainty that every third-party loadable module
was following them, so some security restrictions would still be needed.
Back-patch to 8.2; before that, LOAD was superuser-only anyway.
Security: unprivileged users could crash backend. CVE not assigned yet
functions.
This extends the previous patch that forbade SETting these variables inside
security-definer functions. RESET is equally a security hole, since it
would allow regaining privileges of the caller; furthermore it can trigger
Assert failures and perhaps other internal errors, since the code is not
expecting these variables to change in such contexts. The previous patch
did not cover this case because assign hooks don't really have enough
information, so move the responsibility for preventing this into guc.c.
Problem discovered by Heikki Linnakangas.
Security: no CVE assigned yet, extends CVE-2007-6600
(could happen if either postgresql.conf or postmaster.opts is empty).
It's been broken since the C version was written for 8.0, so patch
all the way back.
initdb's copy of the function is broken in the same way, but it's
less important there since the input files should never be empty.
Patch that in HEAD only, and also fix some cosmetic differences that
crept into that copy of the function.
Per report from Corry Haines and Jeff Davis.
This causes problems when the system load is high, per report from Zdenek
Kotala in <1250860954.1239.114.camel@localhost>; instead of calling kill
directly, have the signal handler set a flag which is checked in ServerLoop.
This way, the handler can return before being called again by a subsequent
signal sent from the autovacuum launcher. Also, increase the sleep in the
launcher in this failure path to 1 second.
Backpatch to 8.3, which is when the signalling between autovacuum
launcher/postmaster was introduced.
Also, add a couple of ReleasePostmasterChildSlot calls in error paths; this
part backpatched to 8.4 which is when the child slot stuff was introduced.
#include the version of history.h that is in the same directory as the
readline.h we are using. This avoids problems in some scenarios where both
readline and editline are installed. Report and patch by Zdenek Kotala.
truncate_identifier won't do anything if the passed-in strlen is already
less than NAMEDATALEN, which it always would be given the strlcpy usage.
This has been broken since the arrays-of-composite-types code went in.
Arguably truncate_identifier is suffering from excessive optimization
and should always process the string, but for the moment I'll take the
more localized patch.
Per bug #4987.
to access a Relation entry it had just closed. I happened to be testing with
CLOBBER_CACHE_ALWAYS, which made this a guaranteed core dump (at least on
machines where sprintf %s isn't forgiving of a NULL pointer). It's probably
quite unlikely that it would fail in the field, but a bug is a bug. Fix by
moving the relation_close call down past the logging action.
that memory allocated by starting third party DLLs doesn't end up
conflicting with it.
Hopefully this solves the long-time issue with "could not reattach
to shared memory" errors on Win32.
Patch from Tsutomu Yamada and me, based on idea from Trevor Talbot.
when we reach the post-COPY "pump it dry" error recovery code that was added
2006-11-24. Per a report from Neil Best, there is at least one code path
in which this occurs, leading to an infinite loop in code that's supposed
to be making it more robust not less so. A reasonable response seems to be
to call PQputCopyEnd() again, so let's try that.
Back-patch to all versions that contain the cleanup loop.
if a smart shutdown is already in progress. Backpatch to 8.3, this was broken
in the patch that introduced "dead-end backends".
Per report by Itagaki Takahiro, patch by Fujii Masao.
we should ignore NULL array entries, not non-NULL ones. This had the
effect of disabling commit_delay, and could have caused a crash in the
rare race condition the patch was intended to fix.
Bug report and diagnosis by Jeff Janes, in bug #4952.
The original coding was not dealing specially with this file being a symlink,
with the end result that it was not installed in VPATH builds. Oddly enough,
the clean target does know about it ...
that the sanity checking I added to create_mergejoin_plan() in 8.3 was a
few bricks shy of a load: the mergeclauses could reference pathkeys in a
noncanonical order such as x,y,x, not only cases like x,x,y which is all
that the code had allowed for. The odd cases only turn up when using
redundant clauses in an outer join condition, which is why no one had
noticed before.
RevalidateCachedPlan. This is to avoid a "SPI_ERROR_CONNECT" failure when
the planner calls a SPI-using function and we are already inside one.
The alternative fix is to expect callers of RevalidateCachedPlan to do this,
which seems likely to result in additional hard-to-detect bugs of omission.
Per reports from Frank van Vugt and Marek Lewczuk.
Back-patch to 8.3. It's much harder to trigger the bug in 8.3, due to a
smaller set of cases in which plans can be invalidated, but it could happen.
(I think perhaps only a SI reset event could make 8.3 fail here, but that's
certainly within the realm of possibility.)
a number of other geometric operators also depend on. It miscalculated the
slope of the perpendicular to the given line segment anytime that slope was
other than 0, infinite, or +/-1. In some cases the error would be masked
because the true closest point on the line segment was one of its endpoints
rather than the intersection point, but in other cases it could give an
arbitrarily bad answer. Per bug #4872 from Nick Roosevelt.
Bug goes clear back to Berkeley days, so patch all supported branches.
Make a couple of cosmetic adjustments while at it.
This prevents autovacuum from reclaiming free space in them and causing
the test's output row order to change, which is causing intermittent
bogus failure reports in the buildfarm.
Backpatch to 8.3. The issue exists further back, but since autovacuum was
not on by default before 8.3, it's not a problem for buildfarm testing.
node starts from the same place as the first scan did. This avoids surprising
behavior of scrollable and WITH HOLD cursors, as seen in Mark Kirkwood's bug
report of yesterday.
It's not entirely clear whether a rescan should be forced to drop out of the
syncscan mode, but for the moment I left the code behaving the same on that
point. Any change there would only be a performance and not a correctness
issue, anyway.
Back-patch to 8.3, since the unstable behavior was created by the syncscan
patch.
eg Japan. Report and fix by Itagaki Takahiro. Also fix CASHDEBUG printout
format for branches with 64-bit money type, and some minor comment cleanup.
Back-patch to 7.4, because it's broken all the way back.
Sergey Burladyan, there are at least some dank corners of libxml2 that
assume this behavior, even though their published documentation suggests
they shouldn't.
This is only really a live problem in 8.3, but the code is still there
for possible debugging use in HEAD, so patch both branches.
should use GinItemPointerGetBlockNumber/GinItemPointerGetOffsetNumber,
not ItemPointerGetBlockNumber/ItemPointerGetOffsetNumber, because the latter
will Assert() on ip_posid == 0, ie a "Min" pointer. (Thus, ItemPointerIsMin
has never worked at all, but it seems unused at present.) I'm not certain
that the case can occur in normal functioning, but it's blowing up on me
while investigating Tatsuo-san's data corruption problem. In any case it
seems like a problem waiting to bite someone.
Back-patch just in case this really is a problem for somebody in the field.
symbolic links with the -l option, and as Fujii Masao pointed out we ended up
overwriting files in the archive directory before this patch. Patch by
Aidan Van Dyk, Fujii Masao and me.
Backpatch to 8.3, where pg_standby was introduced.
this case is worth a special code path, but a special code path that gets
the boundary condition wrong is definitely no good. Per bug #4821 from
Andrew Gierth.
In passing, clean up some minor code formatting issues (excess parentheses
and blank lines in odd places).
Back-patch to 8.3, where the bug was introduced.
there's no analyzable attributes or indexes. We also used to report 0 live
and dead tuples for such tables, which messed with autovacuum threshold
calculations.
This fixes bug #4812 reported by George Su. Backpatch back to 8.1.
xml_parse, all arising from the same sloppy usage of parse_xml_decl.
The original coding had that function returning its output string
parameters in the libxml context, which is long-lived, and all but one
of its callers neglected to free the strings afterwards. The easiest
and most bulletproof fix is to return the strings in the local palloc
context instead, since that's short-lived. This was only costing a
dozen or two bytes per function call, but that adds up fast if the
function is called repeatedly ...
Noted while poking at the more general problem of what to do with our
libxml memory allocation hooks. Back-patch to 8.3, which has the
identical coding.
of AND/OR clause branches that predtest.c would attempt to deal with. As
noted in bug #4721, that change disabled proof attempts for sizes of problems
that people are actually expecting it to work for. The original complaint
it was trying to solve was O(N^2) behavior for long IN-lists, so let's try
applying the limit to just ScalarArrayOpExprs rather than everything.
Another case of "foolish consistency" I fear.
Back-patch to 8.2, same as the previous patch was.
you can end up with an unrecoverable backup if you start a new base backup
right after finishing archive recovery. In that scenario, the redo pointer of
the checkpoint that pg_start_backup() writes points to the XLOG segment where
the timeline-changing end-of-archive-recovery checkpoint is. The beginning
of that segment contains pages with the old timeline ID, and we don't accept
that in recovery unless we find a history file covering the old timeline ID.
If you omit pg_xlog from the base backup and clear the archive directory
before starting the backup, there will be no such history file available.
The bug is present in all versions since PITR was introduced in 8.0, but I'm
back-patching only back to 8.2. Earlier versions didn't have XLOG switch
records, making this fix unfeasible. Given the lack of reports until now,
it doesn't seem worthwhile to spend more effort to fix 8.0 and 8.1.
Per report and suggestion by Mikael Krantz
it fails because the shared memory segment already exists. This
means it can take up to 10 seconds before it reports the error
if it *does* exist, but hopefully it will make the system capable
of restarting even when the server is under high load.
to make sure that the error code is reset, as a precaution in
case the API doesn't properly reset it on success. This could
be necessary, since we check the error value even if the function
doesn't fail for specific success cases.
part that rounds up to exactly 1.0 second. The previous coding rejected input
like "00:12:57.9999999999999999999999999999", with the exact number of nines
needed to cause failure varying depending on float-timestamp option and
possibly on platform. Obviously this should round up to the next integral
second, if we don't have enough precision to distinguish the value from that.
Per bug #4789 from Robert Kruus.
In passing, fix a missed check for fractional seconds in one copy of the
"is it greater than 24:00:00" code.
Broken all the way back, so patch all the way back.
aggregate function. By definition, such a sub-SELECT cannot reference any
variables of query levels between itself and the aggregate's semantic level
(else the aggregate would've been assigned to that lower level instead).
So the correct, most efficient implementation is to treat the sub-SELECT as
being a sub-select of that outer query level, not the level the aggregate
syntactically appears in. Not doing so also confuses the heck out of our
parameter-passing logic, as illustrated in bug report from Daniel Grace.
Fortunately, we were already copying the whole Aggref expression up to the
outer query level, so all that's needed is to delay SS_process_sublinks
processing of the sub-SELECT until control returns to the outer level.
This has been broken since we introduced spec-compliant treatment of
outer aggregates in 7.4; so patch all the way back.
constants through full joins, as in
select * from tenk1 a full join tenk1 b using (unique1)
where unique1 = 42;
which should generate a fairly cheap plan where we apply the constraint
unique1 = 42 in each relation scan. This had been broken by my patch of
2008-06-27, which is now reverted in favor of a more invasive but hopefully
less incorrect approach. That patch was meant to prevent incorrect extraction
of OR'd indexclauses from OR conditions above an outer join. To do that
correctly we need more information than the outerjoin_delay flag can provide,
so add a nullable_relids field to RestrictInfo that records exactly which
relations are nulled by outer joins that are underneath a particular qual
clause. A side benefit is that we can make the test in create_or_index_quals
more specific: it is now smart enough to extract an OR'd indexclause into the
outer side of an outer join, even though it must not do so in the inner side.
The old coding couldn't distinguish these cases so it could not do either.
interval_eq() considers equal. I'm not sure how that fundamental requirement
escaped us through multiple revisions of this hash function, but there it is;
it's been wrong since interval_hash was first written for PG 7.1.
Per bug #4748 from Roman Kononov.
Backpatch to all supported releases.
This patch changes the contents of hash indexes for interval columns. That's
no particular problem for PG 8.4, since we've broken on-disk compatibility
of hash indexes already; but it will require a migration warning note in
the next minor releases of all existing branches: "if you have any hash
indexes on columns of type interval, REINDEX them after updating".
Windows without that, but we shouldn't put bad examples where people might
copy them. Also, reformat slightly to improve the odds that pgindent
won't go nuts on this.
This method will not catch all different ways since the locale
handling in NTFS doesn't provide an easy way to do that, but it
will hopefully solve the most common cases causing startup
problems when the backend is found in the system PATH.
Attempts to fix bug #4694.
we failed to assign, even in "can't happen" cases. Motivated by wondering
what's going on in a recent trouble report where "failed to commit" did
happen.
casting effort whenever the input value was NULL. However this prevents
application of not-null domain constraints in the cases that use this
function, as illustrated in bug #4741. Since this function isn't meant
for use in performance-critical paths anyway, this certainly seems like
another case of "premature optimization is the root of all evil".
Back-patch as far as 8.2; older versions made no effort to enforce
domain constraints here anyway.
at the same instant as a new backend is spawned. Since CountActiveBackends()
doesn't hold ProcArrayLock, it needs to be prepared for the case that a
pointer at the end of the proc array is still NULL even though numProcs says
it should be valid, since it doesn't hold ProcArrayLock. Backpatch to 8.1.
8.0 and earlier had this right, but it was broken in the split of PGPROC and
sinval shared memory arrays.
Per report and proposal by Marko Kreen.
TupleTableSlots. We have functions for retrieving a minimal tuple from a slot
after storing a regular tuple in it, or vice versa; but these were implemented
by converting the internal storage from one format to the other. The problem
with that is it invalidates any pass-by-reference Datums that were already
fetched from the slot, since they'll be pointing into the just-freed version
of the tuple. The known problem cases involve fetching both a whole-row
variable and a pass-by-reference value from a slot that is fed from a
tuplestore or tuplesort object. The added regression tests illustrate some
simple cases, but there may be other failure scenarios traceable to the same
bug. Note that the added tests probably only fail on unpatched code if it's
built with --enable-cassert; otherwise the bug leads to fetching from freed
memory, which will not have been overwritten without additional conditions.
Fix by allowing a slot to contain both formats simultaneously; which turns out
not to complicate the logic much at all, if anything it seems less contorted
than before.
Back-patch to 8.2, where minimal tuples were introduced.
them from degrading badly when the input is sorted or nearly so. In this
scenario the tree is unbalanced to the point of becoming a mere linked list,
so insertions become O(N^2). The easiest and most safely back-patchable
solution is to stop growing the tree sooner, ie limit the growth of N. We
might later consider a rebalancing tree algorithm, but it's not clear that
the benefit would be worth the cost and complexity. Per report from Sergey
Burladyan and an earlier complaint from Heikki.
Back-patch to 8.2; older versions didn't have GIN indexes.
the cause of the "could not write to log file: Bad file descriptor"
errors reported at
http://archives.postgresql.org//pgsql-general/2008-06/msg00193.php
Backpatch to 8.3, the race condition was introduced by the CSV logging
patch.
Analysis and patch by Gurjeet Singh.
format codes are misapplied to a numeric argument. (The code still produces
a pretty bogus error message in such cases, but I'll settle for stopping the
crash for now.) Per bug #4700 from Sergey Burladyan.
Problem exists in all supported branches, so patch all the way back.
In HEAD, also clean up some ugly coding in the nearby cache management
code.
Only needed in 8.3 because it's already this way in HEAD, and older branches
did not support DTrace. This allows external modules to compile on Linux
machines where SystemTap support was recently added, when the required
SystemTap headers are not present on the build machine.
Approach suggested by Tom, after a RPM build trouble report by Devrim Gunduz.
by the planning process. This prevents the "failed to locate grouping columns"
error recently reported by Dickson Guedes. That happens because planning
replaces SubLinks by SubPlans in the subquery's targetlist, and exprTypmod()
is smarter about the former than the latter, causing the apparent type of
the subquery's output columns to change. This seems to be a deficiency we
should fix in exprTypmod(), but that will be a much more invasive patch
with possible side-effects elsewhere, so I'll do that only in HEAD.
Back-patch to 8.3. Arguably the lack of a copying step is broken/dangerous
all the way back, but in the absence of known problems I'll refrain from
making the older branches pay the extra cost. (The reason this particular
symptom didn't appear before is that exprTypmod() wasn't smart about SubLinks
either, until 8.3.)
fail to provide the function itself. Not sure how we escaped testing anything
later than 7.3 on such cases, but they still exist, as per André Volpato's
report about AIX 5.3.
encoding conversion of any elog/ereport message being sent to the frontend.
This generalizes a patch that I put in last October, which suppressed
translation of only specific messages known to be associated with recursive
can't-translate-the-message behavior. As shown in bug #4680, we need a more
general answer in order to have some hope of coping with broken encoding
conversion setups. This approach seems a good deal less klugy anyway.
Patch in all supported branches.
- pg_wchar and wchar_t could have different size, so char2wchar
doesn't call pg_mb2wchar_with_len to prevent out-of-bound
memory bug
- make char2wchar/wchar2char symmetric, now they should not be
called with C-locale because mbstowcs/wcstombs oftenly doesn't
work correct with C-locale.
- Text parser uses pg_mb2wchar_with_len directly in case of
C-locale and multibyte encoding
Per bug report by Hiroshi Inoue <inoue@tpf.co.jp> and
following discussion.
Backpatch up to 8.2 when multybyte support was implemented in tsearch.
fail on zero-length inputs. This isn't an issue in normal use because the
conversion infrastructure skips calling the converters for empty strings.
However a problem was created by yesterday's patch to check whether the
right conversion function is supplied in CREATE CONVERSION. The most
future-proof fix seems to be to make the converters safe for this corner case.
function for the specified source and destination encodings. We do that by
calling the function with an empty string. If it can't perform the requested
conversion, it will throw an error.
Backport to 7.4 - 8.3. Per bug report #4680 by Denis Afonin.
they are out of scope for any code after that anyway, leaving isnull true
should be harmless. However, PL/pgSQL Debugger doesn't seem to care about
the scoping and crashed, per report by Robert Walker (bug #4635). And it's
good to be tidy for debugging purposes too.
Fix in 8.3, 8.2 and 8.1 branches, CVS HEAD was fixed earlier already.
Analysis and fix by Ashesh Vashi and Dave Page.
looks for a CaseTestExpr to figure out what the parser did, but it failed to
consider the possibility that an implicit coercion might be inserted above
the CaseTestExpr. This could result in an Assert failure in some cases
(but correct results if Asserts weren't enabled), or an "unexpected CASE WHEN
clause" error in other cases. Per report from Alan Li.
Back-patch to 8.1; problem doesn't exist before that because CASE was
implemented differently.
TABLE: if the command is executed by someone other than the table owner (eg,
a superuser) and the table has a toast table, the toast table's pg_type row
ends up with the wrong typowner, ie, the command issuer not the table owner.
This is quite harmless for most purposes, since no interesting permissions
checks consult the pg_type row. However, it could lead to unexpected failures
if one later tries to drop the role that issued the command (in 8.1 or 8.2),
or strange warnings from pg_dump afterwards (in 8.3 and up, which will allow
the DROP ROLE because we don't create a "redundant" owner dependency for table
rowtypes). Problem identified by Cott Lang.
Back-patch to 8.1. The problem is actually far older --- the CLUSTER variant
can be demonstrated in 7.0 --- but it's mostly cosmetic before 8.1 because we
didn't track ownership dependencies before 8.1. Also, fixing it before 8.1
would require changing the call signature of heap_create_with_catalog(), which
seems to carry a nontrivial risk of breaking add-on modules.
any LISTEN command. This is more important than it used to be because
DISCARD ALL invokes UNLISTEN. Connection-pooled applications making heavy
use of DISCARD ALL were seeing significant contention for pg_listener,
as reported by Matteo Beccati. It seems unlikely that clients using LISTEN
would use pooled connections, so this simple tweak seems sufficient,
especially since the pg_listener implementation is slated to go away soon
anyway.
Back-patch to 8.3, where DISCARD ALL was introduced.
in the string, not just at the start. Per bug #4629 from Martin Blazek.
Back-patch to 8.2; prior versions don't have the problem, at least not in
the reported case, because they don't try to recognize INTO in non-SELECT
statements. (IOW, this is really fallout from the RETURNING patch.)
from Rushabh Lathia.
Back-patch of patch of 2009-01-08. This is necessary in 8.3, as reported
by Bjorn Munch. It's not currently necessary in 8.2, AFAICS, but seems
best to include it there too.
encoding conversion functions. These are not can't-happen cases because
it's possible to create a conversion with the wrong conversion function
for the specified encoding pair. That would lead to an Assert crash in
an Assert-enabled build, or incorrect conversion otherwise, neither of
which is desirable. This would be a DOS issue if production databases
were customarily built with asserts enabled, but fortunately that's not so.
Per an observation by Heikki.
Back-patch to all supported branches.
to the documented API value. The previous code got it right as
it's implemented, but accepted too much/too little compared to
the API documentation.
Per comment from Zdenek Kotala.
array types for composite types. Although pg_dump understood it wasn't
supposed to dump these array types as separate objects, it must include
them in the dependency ordering analysis, and it was improperly assigning them
the same relatively-high sort priority as regular types. This resulted in
effectively moving composite types and tables up to that same high priority,
which broke any ordering requirements that weren't explicitly enforced by
dependencies. In particular user-defined operator classes, which should come
out before tables, failed to do so. Per report from Brendan Jurd.
In passing, also fix an ill-considered decision to give text search objects
the same sort priority as functions and operators --- the sort result looks
a lot nicer if different object types are kept separate. The recent
foreign-data patch had copied that decision, making the sort ordering even
messier :-(
rewritten into another kind of statement, for example if an INSERT is
rewritten into an UPDATE.
Back-patch to 8.3 and 8.2. For HEAD, Tom suggested inventing a new
SPI_OK_REWRITTEN return code, but that's not a backportable solution. I'll
do that as a separate patch, this patch will do as a stopgap measure for HEAD
too in the meanwhile.
It's not possible to do CREATE DATABASE inside a transaction, so previously
we just got a server error instead.
Backpatch to 8.2, which is where the -1 feature appeared.
OutputFunctionCall, and friends. This allows SPI-using functions to invoke
datatype I/O without concern for the possibility that a SPI-using function
will be called (which could be either the I/O function itself, or a function
used in a domain check constraint). It's a tad ugly, but not nearly as ugly
as what'd be needed to make this work via retail insertion of push/pop
operations in all the PLs.
This reverts my patch of 2007-01-30 that inserted some retail SPI_push/pop
calls into plpgsql; that approach only fixed plpgsql, and not any other PLs.
But the other PLs have the issue too, as illustrated by a recent gripe from
Christian Schröder.
Back-patch to 8.2, which is as far back as this solution will work. It's
also as far back as we need to worry about the domain-constraint case, since
earlier versions did not attempt to check domain constraints within datatype
input. I'm not aware of any old I/O functions that use SPI themselves, so
this should be sufficient for a back-patch.
If the table was smaller than REL_TRUNCATE_FRACTION (= 16) pages, we always
tried to acquire AccessExclusiveLock on it even if there was no empty pages
at the end.
Report by Simon Riggs. Back-patch all the way to 7.4.
is available during datatype input in Bind message processing. I put the
PopActiveSnapshot() or equivalent just before PortalDefineQuery, which is
an unsafe spot for it (in 8.3 and later) because we are carrying a plancache
refcount that hasn't yet been assigned to the portal. Any error thrown there
would result in leaking the refcount. It's not exactly likely that
PopActiveSnapshot would throw an elog, perhaps, but it could happen.
Reorder the code and add another comment warning not to do that.
field needs to be included in equalRuleLocks() comparisons, else updates
will fail to propagate into relcache entries when they have positive
reference count (ie someone is using the relcache entry).
Per report from Alex Hunsaker.
the other major heapam.c functions. The only known consequence of this
omission is that UPDATE RETURNING failed to return the correct value for
"tableoid", as per report from KaiGai Kohei.
Back-patch to 8.2. Arguably it's wrong all the way back; but without
evidence of visible breakage before RETURNING was added, I'll desist from
patching the older branches.
The proposed fix for this is a behavioral change that probably shouldn't
get back-patched, and it doesn't seem worth putting a workaround into
a back branch.
actual argument type of ANYARRAY to match an argument declared ANYARRAY,
so long as ANYELEMENT etc aren't used. I had overlooked the fact that this
is a possible case while fixing bug #3852; but it is possible because
pg_statistic contains columns declared ANYARRAY. Per gripe from Corey Horton.
when they are invoked by the parser. We had been setting up a snapshot at
plan time but really it needs to be done earlier, before parse analysis.
Per report from Dmitry Koterov.
Also fix two related problems discovered while poking at this one:
exec_bind_message called datatype input functions without establishing a
snapshot, and SET CONSTRAINTS IMMEDIATE could call trigger functions without
establishing a snapshot.
Backpatch to 8.2. The underlying problem goes much further back, but it is
masked in 8.1 and before because we didn't attempt to invoke domain check
constraints within datatype input. It would only be exposed if a C-language
datatype input function used the snapshot; which evidently none do, or we'd
have heard complaints sooner. Since this code has changed a lot over time,
a back-patch is hardly risk-free, and so I'm disinclined to patch further
than absolutely necessary.
outer join clauses. Given, say,
... from a left join b on a.a1 = b.b1 where a.a1 = 42;
we'll deduce a clause b.b1 = 42 and then mark the original join clause
redundant (we can't remove it completely for reasons I don't feel like
squeezing into this log entry). However the original implementation of
that wasn't bulletproof, because clause_selectivity() wouldn't honor
this_selec if given nonzero varRelid --- which in practice meant that
it worked as desired *except* when considering index scan quals. Which
resulted in bogus underestimation of the size of the indexscan result for
an inner indexscan in an outer join, and consequently a possibly bad
choice of indexscan vs. bitmap scan. Fix by introducing an explicit test
into clause_selectivity(). Also, to make sure we don't trigger that test
in corner cases, change the convention to be that this_selec > 1, not
this_selec = 1, means it's been marked redundant. Per trouble report from
Scara Maccai.
Back-patch to 8.2, where the problem was introduced.
toasted values, since those could get dropped once the cursor's transaction
is over. Per bug #4553 from Andrew Gierth.
Back-patch as far as 8.1. The bug actually exists back to 7.4 when holdable
cursors were introduced, but this patch won't work before 8.1 without
significant adjustments. Given the lack of field complaints, it doesn't seem
worth the work (and risk of introducing new bugs) to try to make a patch for
the older branches.
This was a thinko introduced in a patch from last February; it results
in memory leakage if an SRF is shut down before the actual end of query,
because subsequent code will be running in a longer-lived context than
it's expecting to be.
for inserting tuples in increasing TID order. It's not clear whether this
fully explains Ivan Sergio Borgonovo's complaint, but simple testing
confirms that a scan that doesn't start at block 0 can slow GIN build by
a factor of three or four.
Backpatch to 8.3. Sync scan didn't exist before that.
AND, OR, or equivalent clauses: if there are too many (more than 100) just
exit without proving anything. This ensures that we don't spend O(N^2) time
trying (and most likely failing) to prove anything about very long IN lists
and similar cases.
Also, install a couple of CHECK_FOR_INTERRUPTS calls to ensure that a long
proof attempt can be interrupted.
Per gripe from Sergey Konoplev.
Back-patch the whole patch to 8.2 and just the CHECK_FOR_INTERRUPTS addition
to 8.1. (The rest of the patch doesn't apply cleanly, and since 8.1 doesn't
show the complained-of behavior anyway, it doesn't seem necessary to work
hard on it.)
we extended the appendrel mechanism to support UNION ALL optimization. The
reason nobody noticed was that we are not actually using attr_needed data for
appendrel children; hence it seems more reasonable to rip it out than fix it.
Back-patch to 8.2 because an Assert failure is possible in corner cases.
Per examination of an example from Jim Nasby.
In HEAD, also get rid of AppendRelInfo.col_mappings, which is quite inadequate
to represent UNION ALL situations; depend entirely on translated_vars instead.
the length of a UTF8 character with pg_mblen (wrong if DB encoding isn't
UTF8), and the latter was blithely assuming that a static buffer would somehow
revert to all zeroes for each use.
in the Global\ namespace, because it caused permission errors on
a lot of platforms.
We need to come up with something better for 8.4, but for now
revert to the pre-8.3.4 behaviour.
