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* Fix whole-row Var evaluation to cope with resjunk columns (again).Tom Lane2012-07-20
| | | | | | | | | | | | | | | | | | When a whole-row Var is reading the result of a subquery, we need it to ignore any "resjunk" columns that the subquery might have evaluated for GROUP BY or ORDER BY purposes. We've hacked this area before, in commit 68e40998d058c1f6662800a648ff1e1ce5d99cba, but that fix only covered whole-row Vars of named composite types, not those of RECORD type; and it was mighty klugy anyway, since it just assumed without checking that any extra columns in the result must be resjunk. A proper fix requires getting hold of the subquery's targetlist so we can actually see which columns are resjunk (whereupon we can use a JunkFilter to get rid of them). So bite the bullet and add some infrastructure to make that possible. Per report from Andrew Dunstan and additional testing by Merlin Moncure. Back-patch to all supported branches. In 8.3, also back-patch commit 292176a118da6979e5d368a4baf27f26896c99a5, which for some reason I had not done at the time, but it's a prerequisite for this change.
* Improve coding around the fsync request queue.Tom Lane2012-07-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In all branches back to 8.3, this patch fixes a questionable assumption in CompactCheckpointerRequestQueue/CompactBgwriterRequestQueue that there are no uninitialized pad bytes in the request queue structs. This would only cause trouble if (a) there were such pad bytes, which could happen in 8.4 and up if the compiler makes enum ForkNumber narrower than 32 bits, but otherwise would require not-currently-planned changes in the widths of other typedefs; and (b) the kernel has not uniformly initialized the contents of shared memory to zeroes. Still, it seems a tad risky, and we can easily remove any risk by pre-zeroing the request array for ourselves. In addition to that, we need to establish a coding rule that struct RelFileNode can't contain any padding bytes, since such structs are copied into the request array verbatim. (There are other places that are assuming this anyway, it turns out.) In 9.1 and up, the risk was a bit larger because we were also effectively assuming that struct RelFileNodeBackend contained no pad bytes, and with fields of different types in there, that would be much easier to break. However, there is no good reason to ever transmit fsync or delete requests for temp files to the bgwriter/checkpointer, so we can revert the request structs to plain RelFileNode, getting rid of the padding risk and saving some marginal number of bytes and cycles in fsync queue manipulation while we are at it. The savings might be more than marginal during deletion of a temp relation, because the old code transmitted an entirely useless but nonetheless expensive-to-process ForgetRelationFsync request to the background process, and also had the background process perform the file deletion even though that can safely be done immediately. In addition, make some cleanup of nearby comments and small improvements to the code in CompactCheckpointerRequestQueue/CompactBgwriterRequestQueue.
* Prevent corner-case core dump in rfree().Tom Lane2012-07-15
| | | | | | | | | | | | | rfree() failed to cope with the case that pg_regcomp() had initialized the regex_t struct but then failed to allocate any memory for re->re_guts (ie, the first malloc call in pg_regcomp() failed). It would try to touch the guts struct anyway, and thus dump core. This is a sufficiently narrow corner case that it's not surprising it's never been seen in the field; but still a bug is a bug, so patch all active branches. Noted while investigating whether we need to call pg_regfree after a failure return from pg_regcomp. Other than this bug, it turns out we don't, so adjust comments appropriately.
* Fix walsender processes to establish a SIGALRM handler.Tom Lane2012-07-12
| | | | | | | | | | | | | | | | | | | | | Walsenders must have working SIGALRM handling during InitPostgres, but they set the handler to SIG_IGN so that nothing would happen if a timeout was reached. This could result in two failure modes: * If a walsender participated in a deadlock during its authentication transaction, and was the last to wait in the deadly embrace, the deadlock would not get cleared automatically. This would require somebody to be trying to take out AccessExclusiveLock on multiple system catalogs, so it's not very probable. * If a client failed to respond to a walsender's authentication challenge, the intended disconnect after AuthenticationTimeout wouldn't happen, and the walsender would wait indefinitely for the client. For the moment, fix in back branches only, since this is fixed in a different way in the timeout-infrastructure patch that's awaiting application to HEAD. If we choose not to apply that, then we'll need to do this in HEAD as well.
* Back-patch fix for extraction of fixed prefixes from regular expressions.Tom Lane2012-07-10
| | | | | | Back-patch of commits 628cbb50ba80c83917b07a7609ddec12cda172d0 and c6aae3042be5249e672b731ebeb21875b5343010. This has been broken since 7.3, so back-patch to all supported branches.
* Back-patch addition of pg_wchar-to-multibyte conversion functionality.Tom Lane2012-07-10
| | | | | | | | | Back-patch of commits 72dd6291f216440f6bb61a8733729a37c7e3b2d2, f6a05fd973a102f7e66c491d3f854864b8d24844, and 60e9c224a197aa37abb1aa3aefa3aad42da61f7f. This is needed to support fixing the regex prefix extraction bug in back branches.
* Refactor pattern_fixed_prefix() to avoid dealing in incomplete patterns.Tom Lane2012-07-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, pattern_fixed_prefix() was defined to return whatever fixed prefix it could extract from the pattern, plus the "rest" of the pattern. That definition was sensible for LIKE patterns, but not so much for regexes, where reconstituting a valid pattern minus the prefix could be quite tricky (certainly the existing code wasn't doing that correctly). Since the only thing that callers ever did with the "rest" of the pattern was to pass it to like_selectivity() or regex_selectivity(), let's cut out the middle-man and just have pattern_fixed_prefix's subroutines do this directly. Then pattern_fixed_prefix can return a simple selectivity number, and the question of how to cope with partial patterns is removed from its API specification. While at it, adjust the API spec so that callers who don't actually care about the pattern's selectivity (which is a lot of them) can pass NULL for the selectivity pointer to skip doing the work of computing a selectivity estimate. This patch is only an API refactoring that doesn't actually change any processing, other than allowing a little bit of useless work to be skipped. However, it's necessary infrastructure for my upcoming fix to regex prefix extraction, because after that change there won't be any simple way to identify the "rest" of the regex, not even to the low level of fidelity needed by regex_selectivity. We can cope with that if regex_fixed_prefix and regex_selectivity communicate directly, but not if we have to work within the old API. Hence, back-patch to all active branches.
* Fix planner to pass correct collation to operator selectivity estimators.Tom Lane2012-07-08
| | | | | | | | | | | | | | | | | | | | | | | | | We can do this without creating an API break for estimation functions by passing the collation using the existing fmgr functionality for passing an input collation as a hidden parameter. The need for this was foreseen at the outset, but we didn't get around to making it happen in 9.1 because of the decision to sort all pg_statistic histograms according to the database's default collation. That meant that selectivity estimators generally need to use the default collation too, even if they're estimating for an operator that will do something different. The reason it's suddenly become more interesting is that regexp interpretation also uses a collation (for its LC_TYPE not LC_COLLATE property), and we no longer want to use the wrong collation when examining regexps during planning. It's not that the selectivity estimate is likely to change much from this; rather that we are thinking of caching compiled regexps during planner estimation, and we won't get the intended benefit if we cache them with a different collation than the executor will use. Back-patch to 9.1, both because the regexp change is likely to get back-patched and because we might as well get this right in all collation-supporting branches, in case any third-party code wants to rely on getting the collation. The patch turns out to be minuscule now that I've done it ...
* Always treat a standby returning an an invalid flush location as asyncMagnus Hagander2012-07-04
| | | | | | | | This ensures that a standby such as pg_receivexlog will not be selected as sync standby - which would cause the master to block waiting for a location that could never happen. Fujii Masao
* Forgot an #include in the previous patch :-(Alvaro Herrera2012-07-03
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* Have REASSIGN OWNED work on extensions, tooAlvaro Herrera2012-07-03
| | | | | | | | | | | | | | | | | Per bug #6593, REASSIGN OWNED fails when the affected role has created an extension. Even though the user related to the extension is not nominally the owner, its OID appears on pg_shdepend and thus causes problems when the user is to be dropped. This commit adds code to change the "ownership" of the extension itself, not of the contained objects. This is fine because it's currently only called from REASSIGN OWNED, which would also modify the ownership of the contained objects. However, this is not sufficient for a working ALTER OWNER implementation extension. Back-patch to 9.1, where extensions were introduced. Bug #6593 reported by Emiliano Leporati.
* Fix race condition in enum value comparisons.Tom Lane2012-07-01
| | | | | | | | | | | | | | | | | | | | | | | | 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.
* Prevent CREATE TABLE LIKE/INHERITS from (mis) copying whole-row Vars.Tom Lane2012-06-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Initialize shared memory copy of ckptXidEpoch correctly when not in recovery.Heikki Linnakangas2012-06-29
| | | | | | | 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
* Fix NOTIFY to cope with I/O problems, such as out-of-disk-space.Tom Lane2012-06-29
| | | | | | | | | | | | | 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.
* 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.