called before, not after, calling the assign_hook if any. This is because
push_old_value might fail (due to palloc out-of-memory), and in that case
there would be no stack entry to tell transaction abort to undo the GUC
assignment. Of course the actual assignment to the GUC variable hasn't
happened yet --- but the assign_hook might have altered subsidiary state.
Without a stack entry we won't call it again to make it undo such actions.
So this is necessary to make the world safe for assign_hooks with side
effects. Per a discussion a couple weeks ago with Magnus.
Back-patch to 8.0. 7.x did not have the problem because it did not have
allocatable stacks of GUC values.
to go beoynd 10MB, as demonstrated by Gavin Sharry's example of dropping a
schema with ~25000 objects. The really bogus thing about the limit was that
it was enforced when a state file file was read in, not when it was written,
so you would end up with a prepared transaction that you can't commit or
abort, and the only recourse was to shut down the server and remove the file
by hand.
Raise the limit to MaxAllocSize, and enforce it also when a state file is
written. We could've removed the limit altogether, but reading in a file
larger than MaxAllocSize would fail anyway because we read it into a
palloc'd buffer.
Backpatch down to 8.1, where 2PC and this issue was introduced.
varoattno along with varattno. This resulted in having Vars that were not
seen as equal(), causing inheritance of the "same" constraint from different
parent relations to fail. An example is
create table pp1 (f1 int check (f1>0));
create table cc1 (f2 text, f3 int) inherits (pp1);
create table cc2(f4 float) inherits(pp1,cc1);
Backpatch as far as 7.4. (The test case still fails in 7.4, for reasons
that I don't feel like investigating at the moment.)
This is a backpatch commit only. The fix will be applied in HEAD as part
of the upcoming pg_constraint patch.
checked to see if it's been initialized to all non-nulls. The implicit NOT
NULL constraint was not being checked during the ALTER (in fact, not even if
there was an explicit NOT NULL too), because ATExecAddColumn neglected to
set the flag needed to make the test happen. This has been broken since
the capability was first added, in 8.0.
Brendan Jurd, per a report from Kaloyan Iliev.
<craig@postnewspapers.com.au>.
It was my mistake, I missed limitation of number of held locks, now GIN doesn't
use continiuous locks, but still hold buffers pinned to prevent interference
with vacuum's deletion algorithm.
corrupted. (Neither is very important if SIGTERM is used to shut down the
whole database cluster together, but there's a problem if someone tries to
SIGTERM individual backends.) To do this, introduce new infrastructure
macros PG_ENSURE_ERROR_CLEANUP/PG_END_ENSURE_ERROR_CLEANUP that take care
of transiently pushing an on_shmem_exit cleanup hook. Also use this method
for createdb cleanup --- that wasn't a shared-memory-corruption problem,
but SIGTERM abort of createdb could leave orphaned files lying around.
Backpatch as far as 8.2. The shmem corruption cases don't exist in 8.1,
and the createdb usage doesn't seem important enough to risk backpatching
further.
it is trying to build a relcache entry for. This is an oversight in my 8.2
patch that tried to ensure we always took a lock on a relation before trying
to build its relcache entry. The implication is that if someone committed a
reindex of a critical system index at about the same time that some other
backend were starting up without a valid pg_internal.init file, the second one
might PANIC due to not seeing any valid version of the index's pg_class row.
Improbable case, but definitely not impossible.
results to contain uninitialized, unpredictable values. While this was okay
as far as the datatypes themselves were concerned, it's a problem for the
parser because occurrences of the "same" literal might not be recognized as
equal by datumIsEqual (and hence not by equal()). It seems sufficient to fix
this in the input functions since the only critical use of equal() is in the
parser's comparisons of ORDER BY and DISTINCT expressions.
Per a trouble report from Marc Cousin.
Patch all the way back. Interestingly, array_in did not have the bug before
8.2, which may explain why the issue went unnoticed for so long.
currently support this because we must be able to build Vars referencing
join columns, and varattno is only 16 bits wide. Perhaps this should be
improved in future, but considering that it never came up before, I'm not
sure the problem is worth much effort. Per bug #4070 from Marcello
Ceschia.
The problem seems largely academic in 8.0 and 7.4, because they have
(different) O(N^2) performance issues with such wide joins, but
back-patch all the way anyway.
The places that did, eg,
(statbuf.st_mode & S_IFMT) == S_IFDIR
were correct, but there is no good reason not to use S_ISDIR() instead,
especially when that's what the other 90% of our code does. The places
that did, eg,
(statbuf.st_mode & S_IFDIR)
were flat out *wrong* and would fail in various platform-specific ways,
eg a symlink could be mistaken for a regular file on most Unixen.
The actual impact of this is probably small, since the problem cases
seem to always involve symlinks or sockets, which are unlikely to be
found in the directories that PG code might be scanning. But it's
clearly trouble waiting to happen, so patch all the way back anyway.
(There seem to be no occurrences of the mistake in 7.4.)
ISO_8859-5 <-> MULE_INTERNAL conversion tables.
This was discovered when trying to convert a string containing those characters
from ISO_8859-5 to Windows-1251, because we use MULE_INTERNAL/KOI8R as an
intermediate encoding between those two.
While the missing "Yo" was just an omission in the conversion tables, there are
a few other characters like the "Numero" sign ("No" as a single character) that
exists in all the other cyrillic encodings (win1251, ISO_8859-5 and cp866), but
not in KOI8R. Added comments about that.
Patch by Sergey Burladyan. Back-patch to 7.4.
case where there is a match to the pattern overall but the user has specified
a parenthesized subexpression and that subexpression hasn't got a match.
An example is substring('foo' from 'foo(bar)?'). This should return NULL,
since (bar) isn't matched, but it was mistakenly returning the whole-pattern
match instead (ie, 'foo'). Per bug #4044 from Rui Martins.
This has been broken since the beginning; patch in all supported versions.
The old behavior was sufficiently inconsistent that it's impossible to believe
anyone is depending on it.
that are reported as "equal" by wcscoll() are checked to see if they really
are bitwise equal, and are sorted per strcmp() if not. We made this happen
a couple of years ago in the regular code path, but it unaccountably got
left out of the Windows/UTF8 case (probably brain fade on my part at the
time). As in the prior set of changes, affected users may need to reindex
indexes on textual columns.
Backpatch as far as 8.2, which is the oldest release we are still supporting
on Windows.
pg_listener modifications commanded by LISTEN and UNLISTEN until the end
of the current transaction. This allows us to hold the ExclusiveLock on
pg_listener until after commit, with no greater risk of deadlock than there
was before. Aside from fixing the race condition, this gets rid of a
truly ugly kludge that was there before, namely having to ignore
HeapTupleBeingUpdated failures during NOTIFY. There is a small potential
incompatibility, which is that if a transaction issues LISTEN or UNLISTEN
and then looks into pg_listener before committing, it won't see any resulting
row insertion or deletion, where before it would have. It seems unlikely
that anyone would be depending on that, though.
This patch also disallows LISTEN and UNLISTEN inside a prepared transaction.
That case had some pretty undesirable properties already, such as possibly
allowing pg_listener entries to be made for PIDs no longer present, so
disallowing it seems like a better idea than trying to maintain the behavior.
TopMemoryContext, rather than scattered through executor per-query contexts.
This poses no danger of memory leak since the ResourceOwner mechanism
guarantees release of no-longer-needed items. It is needed because the
per-query context might already be released by the time we try to clean up
the hash scan list. Report by ykhuang, diagnosis by Heikki.
Back-patch to 8.0, where the ResourceOwner-based cleanup was introduced.
The given test case does not fail before 8.2, probably because we rearranged
transaction abort processing somehow; but this coding is undoubtedly risky
so I'll patch 8.0 and 8.1 anyway.
caches that we don't actually need to touch. This saves some trivial
number of cycles and avoids certain cases of deadlock when doing concurrent
VACUUM FULL on system catalogs. Per report from Gavin Roy.
Backpatch to 8.2. In earlier versions, CatalogCacheInitializeCache didn't
lock the relation so there's no deadlock risk (though that certainly had
plenty of risks of its own).
temporary table; we can't support that because there's no way to clean up the
source backend's internal state if the eventual COMMIT PREPARED is done by
another backend. This was checked correctly in 8.1 but I broke it in 8.2 :-(.
Patch by Heikki Linnakangas, original trouble report by John Smith.
"multi_call_ctx" to be a distinct sub-context of the EState's per-query
context, and delete the multi_call_ctx as soon as the SRF finishes
execution. This avoids leaking SRF memory until the end of the current
query, which is particularly egregious when the SRF is scanned
multiple times. This change also fixes a leak of the fields of the
AttInMetadata struct in shutdown_MultiFuncCall().
Also fix a leak of the SRF result TupleDesc when rescanning a
FunctionScan node. The TupleDesc is allocated in the per-query context
for every call to ExecMakeTableFunctionResult(), so we should free it
after calling that function. Since the SRF might choose to return
a non-expendable TupleDesc, we only free the TupleDesc if it is
not being reference-counted.
Backpatch to 8.3 and 8.2 stable branches.
Formerly, DecodeDate attempted to verify the day-of-the-month exactly, but
it was under the misapprehension that it would know whether we were looking
at a BC year or not. In reality this check can't be made until the calling
function (eg DecodeDateTime) has processed all the fields. So, split the
BC adjustment and validity checks out into a new function ValidateDate that
is called only after processing all the fields. In passing, this patch
makes DecodeTimeOnly work for BC inputs, which it never did before.
(The historical veracity of all this is nonexistent, of course, but if
we're going to say we support proleptic Gregorian calendar then we should
do it correctly. In any case the unpatched code is broken because it could
emit dates that it would then reject on re-inputting.)
Per report from Bernd Helmle. Back-patch as far as 8.0; in 7.x we were
not using our own calendar support and so this seems a bit too risky
to put into 7.4.
OID or new relfilenode. If the existing OIDs are sufficiently densely
populated, this could take a long time (perhaps even be an infinite loop),
so it seems wise to allow the system to respond to a cancel interrupt here.
Per a gripe from Jacky Leng.
Backpatch as far as 8.1. Older versions just fail on OID collision,
instead of looping.
calculating a page's initial free space was fine, and should not have been
"improved" by letting PageGetHeapFreeSpace do it. VACUUM FULL is going to
reclaim LP_DEAD line pointers later, so there is no need for a guard
against the page being too full of line pointers, and having one risks
rejecting pages that are perfectly good move destinations.
This also exposed a second bug, which is that the empty_end_pages logic
assumed that any page with no live tuples would get entered into the
fraged_pages list automatically (by virtue of having more free space than
the threshold in the do_frag calculation). This assumption certainly
seems risky when a low fillfactor has been chosen, and even without
tunable fillfactor I think it could conceivably fail on a page with many
unused line pointers. So fix the code to force do_frag true when notup
is true, and patch this part of the fix all the way back.
Per report from Tomas Szepe.
statement be a list of bare C strings, rather than String nodes, which is
what they need to be for copyfuncs/equalfuncs to work. Fortunately these
node types never go out to disk (if they did, we'd likely have noticed the
problem sooner), so we can just fix it without creating a need for initdb.
This bug has been there since 8.0, but 8.3 exposes it in a more common
code path (Parse messages) than prior releases did. Per bug #3940 from
Vladimir Kokovic.
erroring out of a wait. We can use a PG_TRY block for this, but add a comment
explaining why it'd be a bad idea to use it for any other state cleanup.
Back-patch to 8.2. Prior releases had the same issue, but only with respect
to the process title, which is likely to get reset almost immediately anyway
after the transaction aborts, so it seems not worth changing them. In 8.2
and HEAD, the pg_stat_activity "waiting" flag could remain set incorrectly
for a long time.
Per report from Gurjeet Singh.
Should fix a problem where two clusters are running under
two different service accounts and get colliding names,
causing only the first cluster to contain the pgident
event description.
Per report from Stephen Denne.
subquery output column exactly once left-to-right. Although this is the case
in the original parser output, it might not be so after rewriting and
constant-folding, as illustrated by bug #3882 from Jan Mate. Instead
scan the subquery's target list to obtain needed per-column information;
this is duplicative of what the parser did, but only a couple dozen lines
need be copied, and we can clean up a couple of notational uglinesses.
Bug was introduced in 8.2 as part of revision of SubLink representation.
constraint yields TRUE for every row of its table, only that it does not
yield FALSE (a NULL result isn't disallowed). This breaks a couple of
implications that would be true in two-valued logic. I had put in one such
mistake in an 8.2.5 patch: foo IS NULL doesn't refute a strict operator
on foo. But there was another in the original 8.2 release: NOT foo doesn't
refute an expression whose truth would imply the truth of foo.
Per report from Rajesh Kumar Mallah.
To preserve the ability to do constraint exclusion with one partition
holding NULL values, extend relation_excluded_by_constraints() to check
for attnotnull flags, and add col IS NOT NULL expressions to the set of
constraints we hope to refute.
clauseless joins of relations that have unexploited join clauses. Rather
than looking at every other base relation in the query, the correct thing is
to examine the other relations in the "initial_rels" list of the current
make_rel_from_joinlist() invocation, because those are what we actually have
the ability to join against. This might be a subset of the whole query in
cases where join_collapse_limit or from_collapse_limit or full joins have
prevented merging the whole query into a single join problem. This is a bit
untidy because we have to pass those rels down through a new PlannerInfo
field, but it's necessary. Per bug #3865 from Oleg Kharin.
report of poor planning in 8.3: it's unsafe to push a constant across an
outer join when the outer-join condition is delayed by lower outer joins,
unless we recheck the outer-join condition at the upper outer join.
8.2.x doesn't really have the ability to tell whether this is the case
or not, but fortunately it doesn't matter --- it seems most desirable to
keep the join condition whether it's entirely redundant or not. However,
it's usually mostly redundant, so force its selectivity to 1.0.
It might be a good idea to back-patch this into 8.1 as well, but I'll
refrain until/unless there's evidence that 8.1 actually fails on any
cases that this would fix.
constant ORDER/GROUP BY entries properly:
http://archives.postgresql.org/pgsql-hackers/2001-04/msg00457.php
The original solution to that was in fact no good, as demonstrated by
today's report from Martin Pitt:
http://archives.postgresql.org/pgsql-bugs/2008-01/msg00027.php
We can't use the column-number-reference format for a constant that is
a resjunk targetlist entry, a case that was unfortunately not thought of
in the original discussion. What we can do instead (which did not work
at the time, but does work in 7.3 and up) is to emit the constant with
explicit ::typename decoration, even if it otherwise wouldn't need it.
This is sufficient to keep the parser from thinking it's a column number
reference, and indeed is probably what the user must have done to get
such a thing into the querytree in the first place.
and CLUSTER) execute as the table owner rather than the calling user, using
the same privilege-switching mechanism already used for SECURITY DEFINER
functions. The purpose of this change is to ensure that user-defined
functions used in index definitions cannot acquire the privileges of a
superuser account that is performing routine maintenance. While a function
used in an index is supposed to be IMMUTABLE and thus not able to do anything
very interesting, there are several easy ways around that restriction; and
even if we could plug them all, there would remain a risk of reading sensitive
information and broadcasting it through a covert channel such as CPU usage.
To prevent bypassing this security measure, execution of SET SESSION
AUTHORIZATION and SET ROLE is now forbidden within a SECURITY DEFINER context.
Thanks to Itagaki Takahiro for reporting this vulnerability.
Security: CVE-2007-6600
are shared with Tcl, since it's their code to begin with, and the patches
have been copied from Tcl 8.5.0. Problems:
CVE-2007-4769: Inadequate check on the range of backref numbers allows
crash due to out-of-bounds read.
CVE-2007-4772: Infinite loop in regex optimizer for pattern '($|^)*'.
CVE-2007-6067: Very slow optimizer cleanup for regex with a large NFA
representation, as well as crash if we encounter an out-of-memory condition
during NFA construction.
Part of the response to CVE-2007-6067 is to put a limit on the number of
states in the NFA representation of a regex. This seems needed even though
the within-the-code problems have been corrected, since otherwise the code
could try to use very large amounts of memory for a suitably-crafted regex,
leading to potential DOS by driving the system into swap, activating a kernel
OOM killer, etc.
Although there are certainly plenty of ways to drive the system into effective
DOS with poorly-written SQL queries, these problems seem worth treating as
security issues because many applications might accept regex search patterns
from untrustworthy sources.
Thanks to Will Drewry of Google for reporting these problems. Patches by Will
Drewry and Tom Lane.
Security: CVE-2007-4769, CVE-2007-4772, CVE-2007-6067
since these seem to happen after all in corrupted indexes. Make sure we
supply the index name in all cases, and provide relevant block numbers where
available. Also consistently identify the index name as such.
Back-patch to 8.2, in hopes that this might help Mason Hale figure out his
problem.
The zero-point case is sensible so far as the data structure is concerned,
so maybe we ought to allow it sometime; but right now the textual input
routines for these types don't allow it, and it seems that not all the
functions for the types are prepared to cope.
Report and patch by Merlin Moncure.
out that it's actually quite likely that a string that is an extension of
the given prefix will sort as larger than the "greater" string our previous
code created. To provide some defense against that, do the comparisons
against a modified string instead of just the bare prefix. We tack on
"Z", "z", "y", or "9", whichever is seen as largest in the current locale.
Testing suggests that this is sufficient at least for cases involving
ASCII data.
whole table instead, to ensure that it goes away when the table is dropped.
Per bug #3723 from Sam Mason.
Backpatch as far as 7.4; AFAICT 7.3 does not have the issue, because it doesn't
have general-purpose expression indexes and so there must be at least one
column referenced by an index.
make_greater_string() try harder to generate a string that's actually greater
than its input string. Before we just assumed that making a string that was
memcmp-greater was enough, but it is easy to generate examples where this is
not so when the locale is not C. Instead, loop until the relevant comparison
function agrees that the generated string is greater than the input.
Unfortunately this is probably not enough to guarantee that the generated
string is greater than all extensions of the input, so we cannot relax the
restriction to C locale for the LIKE/regex index optimization. But it should
at least improve the odds of getting a useful selectivity estimate in
prefix_selectivity(). Per example from Guillaume Smet.
Backpatch to 8.1, mainly because that's what the complainant is using...
negated-match operators. patternsel had been using the supplied operator as
though it were a positive-match operator, and thus obtaining a wrong result,
which was even more wrong after the caller subtracted it from 1. Seems
cleanest to give patternsel an explicit "negate" argument so that it knows
what's going on. Also install the same factorization scheme for pattern
join selectivity estimators; even though they are just stubs at the
moment, this may keep someone from making the same type of mistake when
they get filled out. Per report from Greg Mullane.
Backpatch to 8.2 --- previous releases do not show the problem because
patternsel() doesn't actually use the operator directly.
ginRedoInsert(), because other ginRedo* functions rewrite whole page or
make changes which could be applied several times without consistent's loss
- Remove check of identifying of corresponding split record:
it's possible that replaying of WAL starts after actual page split, but before
removing of that split from incomplete splits list. In this case, that check
cause FATAL error.
Per stress test which reproduces bug reported by Craig McElroy
<craig.mcelroy@contegix.com>
usage of any information from system catalog, because it could be called during
replay of WAL.
Per bug report from Craig McElroy <craig.mcelroy@contegix.com>. Patch doesn't
change on-disk storage.
if either of the input relations can legally be joined to any other rels using
join clauses. This avoids uselessly (and expensively) considering a lot of
really stupid join paths when there is a join restriction with a large
footprint, that is, lots of relations inside its LHS or RHS. My patch of
15-Feb-2007 had been causing the code to consider joining *every* combination
of rels inside such a group, which is exponentially bad :-(. With this
behavior, clauseless bushy joins will be done if necessary, but they'll be
put off as long as possible. Per report from Jakub Ouhrabka.
Backpatch to 8.2. We might someday want to backpatch to 8.1 as well, but 8.1
does not have the problem for OUTER JOIN nests, only for IN-clauses, so it's
not clear anyone's very likely to hit it in practice; and the current patch
doesn't apply cleanly to 8.1.
of the sequence. Since OWNED BY never existed before 8.2, this seems
unlikely to create any compatibility issues. Other forms of ALTER SEQUENCE
continue to do what they did before, namely update currval to match the
sequence's actual last_val. That seems wrong on consideration, but we'll
not change it in a minor release --- 8.3 will make that fix.
neglected to test whether an outer join's join-condition actually refers to
the lower outer join it is looking at. (The comment correctly described what
was supposed to happen, but the code didn't do it...) This often resulted in
adding an unnecessary constraint on the join order of the two outer joins,
which was bad enough. However, it also seems to expose a performance
problem in an older patch (from 15-Feb): once we've decided that there is a
join ordering constraint, we will start trying clauseless joins between every
combination of rels within the constraint, which pointlessly eats up lots of
time and space if there are numerous rels below the outer join. That probably
needs to be revisited :-(. Per gripe from Jakub Ouhrabka.
it affects. The original coding neglected tablespace entirely (causing
the indexes to move to the database's default tablespace) and for an index
belonging to a UNIQUE or PRIMARY KEY constraint, it would actually try to
assign the parent table's reloptions to the index :-(. Per bug #3672 and
subsequent investigation.
8.0 and 8.1 did not have reloptions, but the tablespace bug is present.
