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* Fix memory leak in ARRAY(SELECT ...) subqueries.Tom Lane2012-06-21
| | | | | | | | | | | Repeated execution of an uncorrelated ARRAY_SUBLINK sub-select (which I think can only happen if the sub-select is embedded in a larger, correlated subquery) would leak memory for the duration of the query, due to not reclaiming the array generated in the previous execution. Per bug #6698 from Armando Miraglia. Diagnosis and fix idea by Heikki, patch itself by me. This has been like this all along, so back-patch to all supported versions.
* Prevent non-streaming replication connections from being selected sync slaveMagnus Hagander2012-06-11
| | | | | | | | | | | | This prevents a pg_basebackup backup session that just does a base backup (no xlog involved at all) from becoming the synchronous slave and thus blocking all access while it runs. Also fixes the problem when a higher priority slave shows up it would become the sync standby before it has reached the STREAMING state, by making sure we can only switch to a walsender that's actually STREAMING. Fujii Masao
* Fix bug in early startup of Hot Standby with subtransactions.Simon Riggs2012-06-08
| | | | | | | | | | When HS startup is deferred because of overflowed subtransactions, ensure that we re-initialize KnownAssignedXids for when both existing and incoming snapshots have non-zero qualifying xids. Fixes bug #6661 reported by Valentine Gogichashvili. Analysis and fix by Andres Freund
* Wake WALSender to reduce data loss at failover for async commit.Simon Riggs2012-06-07
| | | | | | | | | WALSender now woken up after each background flush by WALwriter, avoiding multi-second replication delay for an all-async commit workload. Replication delay reduced from 7s with default settings to 200ms, allowing significantly reduced data loss at failover. Andres Freund and Simon Riggs
* Avoid early reuse of btree pages, causing incorrect query results.Simon Riggs2012-06-01
| | | | | | | | | | | | | When we allowed read-only transactions to skip assigning XIDs we introduced the possibility that a fully deleted btree page could be reused. This broke the index link sequence which could then lead to indexscans silently returning fewer rows than would have been correct. The actual incidence of silent errors from this is thought to be very low because of the exact workload required and locking pre-conditions. Fix is to remove pages only if index page opaque->btpo.xact precedes RecentGlobalXmin. Noah Misch, reviewed by Simon Riggs
* Translation updatesPeter Eisentraut2012-05-31
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* Revert back-branch changes in behavior of age(xid).Tom Lane2012-05-31
| | | | | | | | Per discussion, it does not seem like a good idea to change the behavior of age(xid) in a minor release, even though the old definition causes the function to fail on hot standby slaves. Therefore, revert commit 5829387381d2e4edf84652bb5a712f6185860670 and follow-on commits in the back branches only.
* Ignore SECURITY DEFINER and SET attributes for a PL's call handler.Tom Lane2012-05-30
| | | | | | | | | | | | | | | | | | | | | | It's not very sensible to set such attributes on a handler function; but if one were to do so, fmgr.c went into infinite recursion because it would call fmgr_security_definer instead of the handler function proper. There is no way for fmgr_security_definer to know that it ought to call the handler and not the original function referenced by the FmgrInfo's fn_oid, so it tries to do the latter, causing the whole process to start over again. Ordinarily such misconfiguration of a procedural language's handler could be written off as superuser error. However, because we allow non-superuser database owners to create procedural languages and the handler for such a language becomes owned by the database owner, it is possible for a database owner to crash the backend, which ideally shouldn't be possible without superuser privileges. In 9.2 and up we will adjust things so that the handler functions are always owned by superusers, but in existing branches this is a minor security fix. Problem noted by Noah Misch (after several of us had failed to detect it :-(). This is CVE-2012-2655.
* Expand the allowed range of timezone offsets to +/-15:59:59 from Greenwich.Tom Lane2012-05-30
| | | | | | | | | | | | | | | We used to only allow offsets less than +/-13 hours, then it was +/14, then it was +/-15. That's still not good enough though, as per today's bug report from Patric Bechtel. This time I actually looked through the Olson timezone database to find the largest offsets used anywhere. The winners are Asia/Manila, at -15:56:00 until 1844, and America/Metlakatla, at +15:13:42 until 1867. So we'd better allow offsets less than +/-16 hours. Given the history, we are way overdue to have some greppable #define symbols controlling this, so make some ... and also remove an obsolete comment that didn't get fixed the last time. Back-patch to all supported branches.
* Teach AbortOutOfAnyTransaction to clean up partially-started transactions.Tom Lane2012-05-28
| | | | | | | | | | | | AbortOutOfAnyTransaction failed to do anything if the state it saw on entry corresponded to failing partway through StartTransaction. I fixed AbortCurrentTransaction to cope with that case way back in commit 60b2444cc3ba037630c9b940c3c9ef01b954b87b, but evidently overlooked that AbortOutOfAnyTransaction should do likewise. Back-patch to all supported branches. It's not clear that this omission has any more-than-cosmetic consequences, but it's also not clear that it doesn't, so back-patching seems the least risky choice.
* Prevent synchronized scanning when systable_beginscan chooses a heapscan.Tom Lane2012-05-26
| | | | | | | | | | | | | | | The only interesting-for-performance case wherein we force heapscan here is when we're rebuilding the relcache init file, and the only such case that is likely to be examining a catalog big enough to be syncscanned is RelationBuildTupleDesc. But the early-exit optimization in that code gets broken if we start the scan at a random place within the catalog, so that allowing syncscan is actually a big deoptimization if pg_attribute is large (at least for the normal case where the rows for core system catalogs have never been changed since initdb). Hence, prevent syncscan here. Per my testing pursuant to complaints from Jeff Frost and Greg Sabino Mullane, though neither of them seem to have actually hit this specific problem. Back-patch to 8.3, where syncscan was introduced.
* Fix string truncation to be multibyte-aware in text_name and bpchar_name.Tom Lane2012-05-25
| | | | | | | | | | | Previously, casts to name could generate invalidly-encoded results. Also, make these functions match namein() more exactly, by consistently using palloc0() instead of ad-hoc zeroing code. Back-patch to all supported branches. Karl Schnaitter and Tom Lane
* Ensure that seqscans check for interrupts at least once per page.Tom Lane2012-05-22
| | | | | | | | | | | | | If a seqscan encounters many consecutive pages containing only dead tuples, it can remain in the loop in heapgettup for a long time, and there was no CHECK_FOR_INTERRUPTS anywhere in that loop. This meant there were real-world situations where a query would be effectively uncancelable for long stretches. Add a check placed to occur once per page, which should be enough to provide reasonable response time without adding any measurable overhead. Report and patch by Merlin Moncure (though I tweaked it a bit). Back-patch to all supported branches.
* Fix error message for COMMENT/SECURITY LABEL ON COLUMN xxx IS 'yyy'Robert Haas2012-05-22
| | | | | | | | When the column name is an unqualified name, rather than table.column, the error message complains about too many dotted names, which is wrong. Report by Peter Eisentraut based on examination of the sepgsql regression test output, but the problem also affects COMMENT. New wording as suggested by Tom Lane.
* Move postmaster's RemovePgTempFiles call to a less randomly chosen place.Tom Lane2012-05-21
| | | | | | | | | | | | | | | | | | There is no reason to do this as early as possible in postmaster startup, and good reason not to do it until we have completely created the postmaster's lock file, namely that it might contribute to pg_ctl thinking that postmaster startup has timed out. (This would require a rather unusual amount of time to be spent scanning temp file directories, but we have at least one field report of it happening reproducibly.) Back-patch to 9.1. Before that, pg_ctl didn't wait for additional info to be added to the lock file, so it wasn't a problem. Note that this is not a complete fix to the slow-start issue in 9.1, because we still had identify_system_timezone being run during postmaster start in 9.1. But that's at least a reasonably well-defined delay, with an easy workaround if needed, whereas the temp-files scan is not so predictable and cannot be avoided.
* Fix bug in to_tsquery().Heikki Linnakangas2012-05-15
| | | | | We were using memcpy() to copy to a possibly overlapping memory region, which is a no-no. Use memmove() instead.
* Fix DROP TABLESPACE to unlink symlink when directory is not there.Tom Lane2012-05-13
| | | | | | | | | | | | | | | | | | | | | If the tablespace directory is missing entirely, we allow DROP TABLESPACE to go through, on the grounds that it should be possible to clean up the catalog entry in such a situation. However, we forgot that the pg_tblspc symlink might still be there. We should try to remove the symlink too (but not fail if it's no longer there), since not doing so can lead to weird behavior subsequently, as per report from Michael Nolan. There was some discussion of adding dependency links to prevent DROP TABLESPACE when the catalogs still contain references to the tablespace. That might be worth doing too, but it's an orthogonal question, and in any case wouldn't be back-patchable. Back-patch to 9.0, which is as far back as the logic looks like this. We could possibly do something similar in 8.x, but given the lack of reports I'm not sure it's worth the trouble, and anyway the case could not arise in the form the logic is meant to cover (namely, a post-DROP transaction rollback having resurrected the pg_tablespace entry after some or all of the filesystem infrastructure is gone).
* Ensure backwards compatibility for GetStableLatestTransactionId()Simon Riggs2012-05-12
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* Prevent loss of init fork when truncating an unlogged table.Robert Haas2012-05-11
| | | | Fixes bug #6635, reported by Akira Kurosawa.
* Remove extraneous #include "storage/proc.h"Simon Riggs2012-05-11
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* Ensure age() returns a stable value rather than the latest valueSimon Riggs2012-05-11
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* On GiST page split, release the locks on child pages before recursing up.Heikki Linnakangas2012-05-11
| | | | | | | | | | | | | | | | | | When inserting the downlinks for a split gist page, we used hold the locks on the child pages until the insertion into the parent - and recursively its parent if it had to be split too - were all completed. Change that so that the locks on child pages are released after the insertion in the immediate parent is done, before recursing further up the tree. This reduces the number of lwlocks that are held simultaneously. Holding many locks is bad for concurrency, and in extreme cases you can even hit the limit of 100 simultaneously held lwlocks in a backend. If you're really unlucky, you can hit the limit while in a critical section, which brings down the whole system. This fixes bug #6629 reported by Tom Forbes. Backpatch to 9.1. The page splitting code was rewritten in 9.1, and the old code did not have this problem.
* Fix Windows implementation of PGSemaphoreLock.Tom Lane2012-05-10
| | | | | | | | | | | | | The original coding failed to reset ImmediateInterruptOK before returning, which would potentially allow a subsequent query-cancel interrupt to be accepted at an unsafe point. This is a really nasty bug since it's so hard to predict the consequences, but they could be unpleasant. Also, ensure that signal handlers are serviced before this function returns, even if the semaphore is already set. This should make the behavior more like Unix. Back-patch to all supported versions.
* Avoid xid error from age() function when run on Hot StandbySimon Riggs2012-05-09
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* Overdue code review for transaction-level advisory locks patch.Tom Lane2012-05-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 62c7bd31c8878dd45c9b9b2429ab7a12103f3590 had assorted problems, most visibly that it broke PREPARE TRANSACTION in the presence of session-level advisory locks (which should be ignored by PREPARE), as per a recent complaint from Stephen Rees. More abstractly, the patch made the LockMethodData.transactional flag not merely useless but outright dangerous, because in point of fact that flag no longer tells you anything at all about whether a lock is held transactionally. This fix therefore removes that flag altogether. We now rely entirely on the convention already in use in lock.c that transactional lock holds must be owned by some ResourceOwner, while session holds are never so owned. Setting the locallock struct's owner link to NULL thus denotes a session hold, and there is no redundant marker for that. PREPARE TRANSACTION now works again when there are session-level advisory locks, and it is also able to transfer transactional advisory locks to the prepared transaction, but for implementation reasons it throws an error if we hold both types of lock on a single lockable object. Perhaps it will be worth improving that someday. Assorted other minor cleanup and documentation editing, as well. Back-patch to 9.1, except that in the 9.1 branch I did not remove the LockMethodData.transactional flag for fear of causing an ABI break for any external code that might be examining those structs.
* Fix printing of whole-row Vars at top level of a SELECT targetlist.Tom Lane2012-04-27
| | | | | | | | | | | | | | | | | | | | | Normally whole-row Vars are printed as "tabname.*". However, that does not work at top level of a targetlist, because per SQL standard the parser will think that the "*" should result in column-by-column expansion; which is not at all what a whole-row Var implies. We used to just print the table name in such cases, which works most of the time; but it fails if the table name matches a column name available anywhere in the FROM clause. This could lead for instance to a view being interpreted differently after dump and reload. Adding parentheses doesn't fix it, but there is a reasonably simple kluge we can use instead: attach a no-op cast, so that the "*" isn't syntactically at top level anymore. This makes the printing of such whole-row Vars a lot more consistent with other Vars, and may indeed fix more cases than just the reported one; I'm suspicious that cases involving schema qualification probably didn't work properly before, either. Per bug report and fix proposal from Abbas Butt, though this patch is quite different in detail from his. Back-patch to all supported versions.
* Fix syslogger's rotation disable/re-enable logic.Tom Lane2012-04-27
| | | | | | | | | | | | | | | | | | If it fails to open a new log file, the syslogger assumes there's something wrong with its parameters (such as log_directory), and stops attempting automatic time-based or size-based log file rotations. Sending it SIGHUP is supposed to start that up again. However, the original coding for that was really bogus, involving clobbering a couple of GUC variables and hoping that SIGHUP processing would restore them. Get rid of that technique in favor of maintaining a separate flag showing we've turned rotation off. Per report from Mark Kirkwood. Also, the syslogger will automatically attempt to create the log_directory directory if it doesn't exist, but that was only happening at startup. For consistency and ease of use, it should do the same whenever the value of log_directory is changed by SIGHUP. Back-patch to all supported branches.
* Fix planner's handling of RETURNING lists in writable CTEs.Tom Lane2012-04-25
| | | | | | | | | | | | | | | | | | | | | | | | setrefs.c failed to do "rtoffset" adjustment of Vars in RETURNING lists, which meant they were left with the wrong varnos when the RETURNING list was in a subquery. That was never possible before writable CTEs, of course, but now it's broken. The executor fails to notice any problem because ExecEvalVar just references the ecxt_scantuple for any normal varno; but EXPLAIN breaks when the varno is wrong, as illustrated in a recent complaint from Bartosz Dmytrak. Since the eventual rtoffset of the subquery is not known at the time we are preparing its plan node, the previous scheme of executing set_returning_clause_references() at that time cannot handle this adjustment. Fortunately, it turns out that we don't really need to do it that way, because all the needed information is available during normal setrefs.c execution; we just have to dig it out of the ModifyTable node. So, do that, and get rid of the kluge of early setrefs processing of RETURNING lists. (This is a little bit of a cheat in the case of inherited UPDATE/DELETE, because we are not passing a "root" struct that corresponds exactly to what the subplan was built with. But that doesn't matter, and anyway this is less ugly than early setrefs processing was.) Back-patch to 9.1, where the problem became possible to hit.
* Fix copyfuncs/equalfuncs support for ReassignOwnedStmt.Robert Haas2012-04-18
| | | | Noah Misch
* Don't wait for the commit record to be replicated if we wrote no WAL.Heikki Linnakangas2012-04-17
| | | | | | | | When using synchronous replication, we waited for the commit record to be replicated, but if we our transaction didn't write any other WAL records, that's not required because we don't even flush the WAL locally to disk in that case. This lead to long waits when committing a transaction that only modified a temporary table. Bug spotted by Thom Brown.
* Clamp indexscan filter condition cost estimate to be not less than zero.Tom Lane2012-04-11
| | | | | | | | | | | | | | | | | cost_index tries to estimate the per-tuple costs of evaluating filter conditions (a/k/a qpquals) by subtracting the estimated cost of the indexqual conditions from that of the baserestrictinfo conditions. This is correct so long as the indexquals list is a subset of the baserestrictinfo list. However, in the presence of derived indexable conditions it's completely wrong, leading to bogus or even negative scan cost estimates, as seen for example in bug #6579 from Istvan Endredy. In practice the problem isn't severe except in the specific case of a LIKE optimization on a functional index containing a very expensive function. A proper fix for this might change cost estimates by more than people would like for stable branches, so in the back branches let's just clamp the cost difference to be not less than zero. That will at least prevent completely insane behavior, while not changing the results normally.
* Ignore missing schemas during non-interactive assignment of search_path.Tom Lane2012-04-11
| | | | | | This aligns 9.1's behavior with that of older branches. HEAD is now even laxer, ignoring missing schemas all the time, but that seems like too big a change for a released branch. Per complaint from Robert Haas.
* Fix an Assert that turns out to be reachable after all.Tom Lane2012-04-09
| | | | | | | | | estimate_num_groups() gets unhappy with create table empty(); select * from empty except select * from empty e2; I can't see any actual use-case for such a query (and the table is illegal per SQL spec), but it seems like a good idea that it not cause an assert failure.
* set_stack_base() no longer needs to be called in PostgresMain.Heikki Linnakangas2012-04-08
| | | | | | This was a thinko in previous commit. Now that stack base pointer is now set in PostmasterMain and SubPostmasterMain, it doesn't need to be set in PostgresMain anymore.
* Do stack-depth checking in all postmaster children.Heikki Linnakangas2012-04-08
| | | | | | | | | | | | | | | | | | | We used to only initialize the stack base pointer when starting up a regular backend, not in other processes. In particular, autovacuum workers can run arbitrary user code, and without stack-depth checking, infinite recursion in e.g an index expression will bring down the whole cluster. The comment about PL/Java using set_stack_base() is not yet true. As the code stands, PL/java still modifies the stack_base_ptr variable directly. However, it's been discussed in the PL/Java mailing list that it should be changed to use the function, because PL/Java is currently oblivious to the register stack used on Itanium. There's another issues with PL/Java, namely that the stack base pointer it sets is not really the base of the stack, it could be something close to the bottom of the stack. That's a separate issue that might need some further changes to this code, but that's a different story. Backpatch to all supported releases.
* Fix misleading output from gin_desc().Tom Lane2012-04-06
| | | | | | | | | | | XLOG_GIN_UPDATE_META_PAGE and XLOG_GIN_DELETE_LISTPAGE records were printed with a list link field labeled as "blkno", which was confusing, especially when the link was empty (InvalidBlockNumber). Print the metapage block number instead, since that's what's actually being updated. We could include the link values too as a separate field, but not clear it's worth the trouble. Back-patch to 8.4 where the dubious code was added.
* Fix syslogger to not lose log coherency under high load.Tom Lane2012-04-04
| | | | | | | | | The original coding of the syslogger had an arbitrary limit of 20 large messages concurrently in progress, after which it would just punt and dump message fragments to the output file separately. Our ambitions are a bit higher than that now, so allow the data structure to expand as necessary. Reported and patched by Andrew Dunstan; some editing by Tom
* Correct epoch of txid_current() when executed on a Hot Standby server.Simon Riggs2012-03-29
| | | | | | | | | Initialise ckptXidEpoch from starting checkpoint and maintain the correct value as we roll forwards. This allows GetNextXidAndEpoch() to return the correct epoch when executed during recovery. Backpatch to 9.0 when the problem is first observable by a user. Bug report from Daniel Farina
* Fix COPY FROM for null marker strings that correspond to invalid encoding.Tom Lane2012-03-25
| | | | | | | | | | | | | The COPY documentation says "COPY FROM matches the input against the null string before removing backslashes". It is therefore reasonable to presume that null markers like E'\\0' will work ... and they did, until someone put the tests in the wrong order during microoptimization-driven rewrites. Since then, we've been failing if the null marker is something that would de-escape to an invalidly-encoded string. Since null markers generally need to be something that can't appear in the data, this represents a nontrivial loss of functionality; surprising nobody noticed it earlier. Per report from Jeff Davis. Backpatch to 8.4 where this got broken.
* Fix planner's handling of outer PlaceHolderVars within subqueries.Tom Lane2012-03-24
| | | | | | | | | | | | | | | | | | | | | | | For some reason, in the original coding of the PlaceHolderVar mechanism I had supposed that PlaceHolderVars couldn't propagate into subqueries. That is of course entirely possible. When it happens, we need to treat an outer-level PlaceHolderVar much like an outer Var or Aggref, that is SS_replace_correlation_vars() needs to replace the PlaceHolderVar with a Param, and then when building the finished SubPlan we have to provide the PlaceHolderVar expression as an actual parameter for the SubPlan. The handling of the contained expression is a bit delicate but it can be treated exactly like an Aggref's expression. In addition to the missing logic in subselect.c, prepjointree.c was failing to search subqueries for PlaceHolderVars that need their relids adjusted during subquery pullup. It looks like everyplace else that touches PlaceHolderVars got it right, though. Per report from Mark Murawski. In 9.1 and HEAD, queries affected by this oversight would fail with "ERROR: Upper-level PlaceHolderVar found where not expected". But in 9.0 and 8.4, you'd silently get possibly-wrong answers, since the value transmitted into the subquery wouldn't go to null when it should.
* Cast some printf arguments to avoid possibly-nonportable behavior.Tom Lane2012-03-23
| | | | Per compiler warnings on buildfarm member black_firefly.
* Don't allow CREATE TABLE AS to put relations in pg_global.Robert Haas2012-03-21
| | | | | | | | | | | | | This was never intended to be allowed, and is blocked for an ordinary CREATE TABLE, but CREATE TABLE AS slipped through the cracks. This commit won't do anything to fix existing cases where this has loophole has been exploited, but it still seems prudent to lock it down going forward. Back-branch commit only, as this problem has been refactored away on the master branch. Andres Freund
* Fix bug where walsender goes into a busy loop if connection is terminated.Heikki Linnakangas2012-03-21
| | | | | | | | | | | The problem was that ResetLatch was not being called in the walsender loop if the connection was terminated, so WaitLatch never sleeps until the terminated connection is detected. In the master-branch, this was already fixed as a side-effect of some refactoring of the loop. This commit backports that refactoring to 9.1. 9.0 does not have this bug, because we didn't use latches back then. Fujii Masao
* Revisit handling of UNION ALL subqueries with non-Var output columns.Tom Lane2012-03-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 57664ed25e5dea117158a2e663c29e60b3546e1c I tried to fix a bug reported by Teodor Sigaev by making non-simple-Var output columns distinct (by wrapping their expressions with dummy PlaceHolderVar nodes). This did not work too well. Commit b28ffd0fcc583c1811e5295279e7d4366c3cae6c fixed some ensuing problems with matching to child indexes, but per a recent report from Claus Stadler, constraint exclusion of UNION ALL subqueries was still broken, because constant-simplification didn't handle the injected PlaceHolderVars well either. On reflection, the original patch was quite misguided: there is no reason to expect that EquivalenceClass child members will be distinct. So instead of trying to make them so, we should ensure that we can cope with the situation when they're not. Accordingly, this patch reverts the code changes in the above-mentioned commits (though the regression test cases they added stay). Instead, I've added assorted defenses to make sure that duplicate EC child members don't cause any problems. Teodor's original problem ("MergeAppend child's targetlist doesn't match MergeAppend") is addressed more directly by revising prepare_sort_from_pathkeys to let the parent MergeAppend's sort list guide creation of each child's sort list. In passing, get rid of add_sort_column; as far as I can tell, testing for duplicate sort keys at this stage is dead code. Certainly it doesn't trigger often enough to be worth expending cycles on in ordinary queries. And keeping the test would've greatly complicated the new logic in prepare_sort_from_pathkeys, because comparing pathkey list entries against a previous output array requires that we not skip any entries in the list. Back-patch to 9.1, like the previous patches. The only known issue in this area that wasn't caused by the ill-advised previous patches was the MergeAppend planning failure, which of course is not relevant before 9.1. It's possible that we need some of the new defenses against duplicate child EC entries in older branches, but until there's some clear evidence of that I'm going to refrain from back-patching further.
* Fix some issues with temp/transient tables in extension scripts.Tom Lane2012-03-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Phil Sorber reported that a rewriting ALTER TABLE within an extension update script failed, because it creates and then drops a placeholder table; the drop was being disallowed because the table was marked as an extension member. We could hack that specific case but it seems likely that there might be related cases now or in the future, so the most practical solution seems to be to create an exception to the general rule that extension member objects can only be dropped by dropping the owning extension. To wit: if the DROP is issued within the extension's own creation or update scripts, we'll allow it, implicitly performing an "ALTER EXTENSION DROP object" first. This will simplify cases such as extension downgrade scripts anyway. No docs change since we don't seem to have documented the idea that you would need ALTER EXTENSION DROP for such an action to begin with. Also, arrange for explicitly temporary tables to not get linked as extension members in the first place, and the same for the magic pg_temp_nnn schemas that are created to hold them. This prevents assorted unpleasant results if an extension script creates a temp table: the forced drop at session end would either fail or remove the entire extension, and neither of those outcomes is desirable. Note that this doesn't fix the ALTER TABLE scenario, since the placeholder table is not temp (unless the table being rewritten is). Back-patch to 9.1.
* Allow child-relation entries to be made in ec_has_const EquivalenceClasses.Tom Lane2012-03-02
| | | | | | | | | | | | | | | | | | | | | | This fixes an oversight in commit 11cad29c91524aac1d0b61e0ea0357398ab79bf8, which introduced MergeAppend plans. Before that happened, we never particularly cared about the sort ordering of scans of inheritance child relations, since appending their outputs together would destroy any ordering anyway. But now it's important to be able to match child relation sort orderings to those of the surrounding query. The original coding of add_child_rel_equivalences skipped ec_has_const EquivalenceClasses, on the originally-correct grounds that adding child expressions to them was useless. The effect of this is that when a parent variable is equated to a constant, we can't recognize that index columns on the equivalent child variables are not sort-significant; that is, we can't recognize that a child index on, say, (x, y) is able to generate output in "ORDER BY y" order when there is a clause "WHERE x = constant". Adding child expressions to the (x, constant) EquivalenceClass fixes this, without any downside that I can see other than a few more planner cycles expended on such queries. Per recent gripe from Robert McGehee. Back-patch to 9.1 where MergeAppend was introduced.
* Correctly detect SSI conflicts of prepared transactions after crash.Heikki Linnakangas2012-02-29
| | | | | | | | | | | | A prepared transaction can get new conflicts in and out after preparing, so we cannot rely on the in- and out-flags stored in the statefile at prepare- time. As a quick fix, make the conservative assumption that after a restart, all prepared transactions are considered to have both in- and out-conflicts. That can lead to unnecessary rollbacks after a crash, but that shouldn't be a big problem in practice; you don't want prepared transactions to hang around for a long time anyway. Dan Ports
* Fix some more bugs in GIN's WAL replay logic.Tom Lane2012-02-26
| | | | | | | | | | | | | | | | | | In commit 4016bdef8aded77b4903c457050622a5a1815c16 I fixed a bunch of ginxlog.c bugs having to do with not handling XLogReadBuffer failures correctly. However, in ginRedoUpdateMetapage and ginRedoDeleteListPages, I unaccountably thought that failure to read the metapage would be impossible and just put in an elog(PANIC) call. This is of course wrong: failure is exactly what will happen if the index got dropped (or rebuilt) between creation of the WAL record and the crash we're trying to recover from. I believe this explains Nicholas Wilson's recent report of these errors getting reached. Also, fix memory leak in forgetIncompleteSplit. This wasn't of much concern when the code was written, but in a long-running standby server page split records could be expected to accumulate indefinitely. Back-patch to 8.4 --- before that, GIN didn't have a metapage.
* Remove arbitrary limitation on length of common name in SSL certificates.Tom Lane2012-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both libpq and the backend would truncate a common name extracted from a certificate at 32 bytes. Replace that fixed-size buffer with dynamically allocated string so that there is no hard limit. While at it, remove the code for extracting peer_dn, which we weren't using for anything; and don't bother to store peer_cn longer than we need it in libpq. This limit was not so terribly unreasonable when the code was written, because we weren't using the result for anything critical, just logging it. But now that there are options for checking the common name against the server host name (in libpq) or using it as the user's name (in the server), this could result in undesirable failures. In the worst case it even seems possible to spoof a server name or user name, if the correct name is exactly 32 bytes and the attacker can persuade a trusted CA to issue a certificate in which that string is a prefix of the certificate's common name. (To exploit this for a server name, he'd also have to send the connection astray via phony DNS data or some such.) The case that this is a realistic security threat is a bit thin, but nonetheless we'll treat it as one. Back-patch to 8.4. Older releases contain the faulty code, but it's not a security problem because the common name wasn't used for anything interesting. Reported and patched by Heikki Linnakangas Security: CVE-2012-0867
* Require execute permission on the trigger function for CREATE TRIGGER.Tom Lane2012-02-23
| | | | | | | | | | | | | | | | | This check was overlooked when we added function execute permissions to the system years ago. For an ordinary trigger function it's not a big deal, since trigger functions execute with the permissions of the table owner, so they couldn't do anything the user issuing the CREATE TRIGGER couldn't have done anyway. However, if a trigger function is SECURITY DEFINER, that is not the case. The lack of checking would allow another user to install it on his own table and then invoke it with, essentially, forged input data; which the trigger function is unlikely to realize, so it might do something undesirable, for instance insert false entries in an audit log table. Reported by Dinesh Kumar, patch by Robert Haas Security: CVE-2012-0866