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2012-07-01Fix race condition in enum value comparisons.Tom Lane
When (re) loading the typcache comparison cache for an enum type's values, use an up-to-date MVCC snapshot, not the transaction's existing snapshot. This avoids problems if we encounter an enum OID that was created since our transaction started. Per report from Andres Freund and diagnosis by Robert Haas. To ensure this is safe even if enum comparison manages to get invoked before we've set a transaction snapshot, tweak GetLatestSnapshot to redirect to GetTransactionSnapshot instead of throwing error when FirstSnapshotSet is false. The existing uses of GetLatestSnapshot (in ri_triggers.c) don't care since they couldn't be invoked except in a transaction that's already done some work --- but it seems just conceivable that this might not be true of enums, especially if we ever choose to use enums in system catalogs. Note that the comparable coding in enum_endpoint and enum_range_internal remains GetTransactionSnapshot; this is perhaps debatable, but if we changed it those functions would have to be marked volatile, which doesn't seem attractive. Back-patch to 9.1 where ALTER TYPE ADD VALUE was added.
2012-06-30Prevent CREATE TABLE LIKE/INHERITS from (mis) copying whole-row Vars.Tom Lane
If a CHECK constraint or index definition contained a whole-row Var (that is, "table.*"), an attempt to copy that definition via CREATE TABLE LIKE or table inheritance produced incorrect results: the copied Var still claimed to have the rowtype of the source table, rather than the created table. For the LIKE case, it seems reasonable to just throw error for this situation, since the point of LIKE is that the new table is not permanently coupled to the old, so there's no reason to assume its rowtype will stay compatible. In the inheritance case, we should ideally allow such constraints, but doing so will require nontrivial refactoring of CREATE TABLE processing (because we'd need to know the OID of the new table's rowtype before we adjust inherited CHECK constraints). In view of the lack of previous complaints, that doesn't seem worth the risk in a back-patched bug fix, so just make it throw error for the inheritance case as well. Along the way, replace change_varattnos_of_a_node() with a more robust function map_variable_attnos(), which is capable of being extended to handle insertion of ConvertRowtypeExpr whenever we get around to fixing the inheritance case nicely, and in the meantime it returns a failure indication to the caller so that a helpful message with some context can be thrown. Also, this code will do the right thing with subselects (if we ever allow them in CHECK or indexes), and it range-checks varattnos before using them to index into the map array. Per report from Sergey Konoplev. Back-patch to all supported branches.
2012-06-29Initialize shared memory copy of ckptXidEpoch correctly when not in recovery.Heikki Linnakangas
This bug was introduced by commit 20d98ab6e4110087d1816cd105a40fcc8ce0a307, so backpatch this to 9.0-9.2 like that one. This fixes bug #6710, reported by Tarvi Pillessaar
2012-06-29Fix NOTIFY to cope with I/O problems, such as out-of-disk-space.Tom Lane
The LISTEN/NOTIFY subsystem got confused if SimpleLruZeroPage failed, which would typically happen as a result of a write() failure while attempting to dump a dirty pg_notify page out of memory. Subsequently, all attempts to send more NOTIFY messages would fail with messages like "Could not read from file "pg_notify/nnnn" at offset nnnnn: Success". Only restarting the server would clear this condition. Per reports from Kevin Grittner and Christoph Berg. Back-patch to 9.0, where the problem was introduced during the LISTEN/NOTIFY rewrite.
2012-06-25Improve pg_dump's dependency-sorting logic to enforce section dump order.Tom Lane
As of 9.2, with the --section option, it is very important that the concept of "pre data", "data", and "post data" sections of the output be honored strictly; else a dump divided into separate sectional files might be unrestorable. However, the dependency-sorting logic knew nothing of sections and would happily select output orderings that didn't fit that structure. Doing so was mostly harmless before 9.2, but now we need to be sure it doesn't do that. To fix, create dummy objects representing the section boundaries and add dependencies between them and all the normal objects. (This might sound expensive but it seems to only add a percent or two to pg_dump's runtime.) This also fixes a problem introduced in 9.1 by the feature that allows incomplete GROUP BY lists when a primary key is given in GROUP BY. That means that views can depend on primary key constraints. Previously, pg_dump would deal with that by simply emitting the primary key constraint before the view definition (and hence before the data section of the output). That's bad enough for simple serial restores, where creating an index before the data is loaded works, but is undesirable for speed reasons. But it could lead to outright failure of parallel restores, as seen in bug #6699 from Joe Van Dyk. That happened because pg_restore would switch into parallel mode as soon as it reached the constraint, and then very possibly would try to emit the view definition before the primary key was committed (as a consequence of another bug that causes the view not to be correctly marked as depending on the constraint). Adding the section boundary constraints forces the dependency-sorting code to break the view into separate table and rule declarations, allowing the rule, and hence the primary key constraint it depends on, to revert to their intended location in the post-data section. This also somewhat accidentally works around the bogus-dependency-marking problem, because the rule will be correctly shown as depending on the constraint, so parallel pg_restore will now do the right thing. (We will fix the bogus-dependency problem for real in a separate patch, but that patch is not easily back-portable to 9.1, so the fact that this patch is enough to dodge the only known symptom is fortunate.) Back-patch to 9.1, except for the hunk that adds verification that the finished archive TOC list is in correct section order; the place where it was convenient to add that doesn't exist in 9.1.
2012-06-21Fix memory leak in ARRAY(SELECT ...) subqueries.Tom Lane
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.
2012-06-19pg_dump: Fix verbosity level in LO progress messagesAlvaro Herrera
In passing, reword another instance of the same message that was gratuitously different. Author: Josh Kupershmidt after a bug report by Bosco Rama
2012-06-19Update copyright year in forgotten placesPeter Eisentraut
found by Stefan Kaltenbrunner
2012-06-11Prevent non-streaming replication connections from being selected sync slaveMagnus Hagander
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
2012-06-08Fix bug in early startup of Hot Standby with subtransactions.Simon Riggs
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
2012-06-07Wake WALSender to reduce data loss at failover for async commit.Simon Riggs
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
2012-06-05Backpatch error message fix from 81f6bbe8ade8c90f23f9286ca9ca726d3e0e310fMagnus Hagander
Without this, pg_basebackup doesn't tell you why it failed when for example there is a file in the data directory that the backend doesn't have permissions to read.
2012-06-01Avoid early reuse of btree pages, causing incorrect query results.Simon Riggs
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
2012-05-31Stamp 9.1.4.REL9_1_4Tom Lane
2012-05-31Translation updatesPeter Eisentraut
2012-05-31Revert back-branch changes in behavior of age(xid).Tom Lane
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.
2012-05-31Update time zone data files to tzdata release 2012c.Tom Lane
DST law changes in Antarctica, Armenia, Chile, Cuba, Falkland Islands, Gaza, Haiti, Hebron, Morocco, Syria, Tokelau Islands. Historical corrections for Canada.
2012-05-30Ignore SECURITY DEFINER and SET attributes for a PL's call handler.Tom Lane
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.
2012-05-30Expand the allowed range of timezone offsets to +/-15:59:59 from Greenwich.Tom Lane
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.
2012-05-28Teach AbortOutOfAnyTransaction to clean up partially-started transactions.Tom Lane
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.
2012-05-26Prevent synchronized scanning when systable_beginscan chooses a heapscan.Tom Lane
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.
2012-05-25Fix string truncation to be multibyte-aware in text_name and bpchar_name.Tom Lane
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
2012-05-25Use binary search instead of brute-force scan in findNamespace().Tom Lane
The previous coding presented a significant bottleneck when dumping databases containing many thousands of schemas, since the total time spent searching would increase roughly as O(N^2) in the number of objects. Noted by Jeff Janes, though I rewrote his proposed patch to use the existing findObjectByOid infrastructure. Since this is a longstanding performance bug, backpatch to all supported versions.
2012-05-22Ensure that seqscans check for interrupts at least once per page.Tom Lane
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.
2012-05-22Fix error message for COMMENT/SECURITY LABEL ON COLUMN xxx IS 'yyy'Robert Haas
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.
2012-05-21Move postmaster's RemovePgTempFiles call to a less randomly chosen place.Tom Lane
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.
2012-05-15Fix bug in to_tsquery().Heikki Linnakangas
We were using memcpy() to copy to a possibly overlapping memory region, which is a no-no. Use memmove() instead.
2012-05-13Fix DROP TABLESPACE to unlink symlink when directory is not there.Tom Lane
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).
2012-05-12Ensure backwards compatibility for GetStableLatestTransactionId()Simon Riggs
2012-05-11Prevent loss of init fork when truncating an unlogged table.Robert Haas
Fixes bug #6635, reported by Akira Kurosawa.
2012-05-11Remove extraneous #include "storage/proc.h"Simon Riggs
2012-05-11Ensure age() returns a stable value rather than the latest valueSimon Riggs
2012-05-11On GiST page split, release the locks on child pages before recursing up.Heikki Linnakangas
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.
2012-05-10Fix Windows implementation of PGSemaphoreLock.Tom Lane
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.
2012-05-10Only attempt to show collations on servers >= 9.1.Magnus Hagander
Show a proper error message instead of a SQL error. Josh Kupershmidt
2012-05-09PL/pgSQL RETURN NEXT was leaking converted tuples, causingJoe Conway
out of memory when looping through large numbers of rows. Flag the converted tuples to be freed. Complaint and patch by Joe.
2012-05-09Avoid xid error from age() function when run on Hot StandbySimon Riggs
2012-05-04Overdue code review for transaction-level advisory locks patch.Tom Lane
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.
2012-04-27Fix printing of whole-row Vars at top level of a SELECT targetlist.Tom Lane
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.
2012-04-27Fix syslogger's rotation disable/re-enable logic.Tom Lane
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.
2012-04-26PL/Python: Accept strings in functions returning composite typesPeter Eisentraut
Before 9.1, PL/Python functions returning composite types could return a string and it would be parsed using record_in. The 9.1 changes made PL/Python only expect dictionaries, tuples, or objects supporting getattr as output of composite functions, resulting in a regression and a confusing error message, as the strings were interpreted as sequences and the code for transforming lists to database tuples was used. Fix this by treating strings separately as before, before checking for the other types. The reason why it's important to support string to database tuple conversion is that trigger functions on tables with composite columns get the composite row passed in as a string (from record_out). Without supporting converting this back using record_in, this makes it impossible to implement pass-through behavior for these columns, as PL/Python no longer accepts strings for composite values. A better solution would be to fix the code that transforms composite inputs into Python objects to produce dictionaries that would then be correctly interpreted by the Python->PostgreSQL counterpart code. But that would be too invasive to backpatch to 9.1, and it is too late in the 9.2 cycle to attempt it. It should be revisited in the future, though. Reported as bug #6559 by Kirill Simonov. Jan UrbaƄski
2012-04-25Fix planner's handling of RETURNING lists in writable CTEs.Tom Lane
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.
2012-04-25Fix edge-case behavior of pg_next_dst_boundary().Tom Lane
Due to rather sloppy thinking (on my part, I'm afraid) about the appropriate behavior for boundary conditions, pg_next_dst_boundary() gave undefined, platform-dependent results when the input time is exactly the last recorded DST transition time for the specified time zone, as a result of fetching values one past the end of its data arrays. Change its specification to be that it always finds the next DST boundary *after* the input time, and adjust code to match that. The sole existing caller, DetermineTimeZoneOffset, doesn't actually care about this distinction, since it always uses a probe time earlier than the instant that it does care about. So it seemed best to me to change the API to make the result=1 and result=0 cases more consistent, specifically to ensure that the "before" outputs always describe the state at the given time, rather than hacking the code to obey the previous API comment exactly. Per bug #6605 from Sergey Burladyan. Back-patch to all supported versions.
2012-04-25PL/Python: Improve error messagesPeter Eisentraut
2012-04-18Revert recent commit re positional arguments.Andrew Dunstan
2012-04-18Fix copyfuncs/equalfuncs support for ReassignOwnedStmt.Robert Haas
Noah Misch
2012-04-17Don't override arguments set via options with positional arguments.Andrew Dunstan
A number of utility programs were rather careless about paremeters that can be set via both an option argument and a positional argument. This leads to results which can violate the Principal Of Least Astonishment. These changes refuse to use positional arguments to override settings that have been made via positional arguments. The changes are backpatched to all live branches.
2012-04-17Don't wait for the commit record to be replicated if we wrote no WAL.Heikki Linnakangas
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.
2012-04-11Clamp indexscan filter condition cost estimate to be not less than zero.Tom Lane
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.
2012-04-11Ignore missing schemas during non-interactive assignment of search_path.Tom Lane
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.