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* Add missing period to detail message.Robert Haas2012-08-30
| | | | Per note from Peter Eisentraut.
* Back-patch fixes for some issues in our Windows socket code into 9.1.Robert Haas2012-08-27
| | | | | | This is a backport of commit b85427f2276d02756b558c0024949305ea65aca5. Per discussion of bug #4958. Some of these fixes probably need to be back-patched further, but I'm just doing this much for now.
* Fix issues with checks for unsupported transaction states in Hot Standby.Tom Lane2012-08-24
| | | | | | | | | | | | | | | | | | | | | | | | | The GUC check hooks for transaction_read_only and transaction_isolation tried to check RecoveryInProgress(), so as to disallow setting read/write mode or serializable isolation level (respectively) in hot standby sessions. However, GUC check hooks can be called in many situations where we're not connected to shared memory at all, resulting in a crash in RecoveryInProgress(). Among other cases, this results in EXEC_BACKEND builds crashing during child process start if default_transaction_isolation is serializable, as reported by Heikki Linnakangas. Protect those calls by silently allowing any setting when not inside a transaction; which is okay anyway since these GUCs are always reset at start of transaction. Also, add a check to GetSerializableTransactionSnapshot() to complain if we are in hot standby. We need that check despite the one in check_XactIsoLevel() because default_transaction_isolation could be serializable. We don't want to complain any sooner than this in such cases, since that would prevent running transactions at all in such a state; but a transaction can be run, if SET TRANSACTION ISOLATION is done before setting a snapshot. Per report some months ago from Robert Haas. Back-patch to 9.1, since these problems were introduced by the SSI patch. Kevin Grittner and Tom Lane, with ideas from Heikki Linnakangas
* Fix cascading privilege revoke to notice when privileges are still held.Tom Lane2012-08-23
| | | | | | | | | | | | If we revoke a grant option from some role X, but X still holds the option via another grant, we should not recursively revoke the privilege from role(s) Y that X had granted it to. This was supposedly fixed as one aspect of commit 4b2dafcc0b1a579ef5daaa2728223006d1ff98e9, but I must not have tested it, because in fact that code never worked: it forgot to shift the grant-option bits back over when masking the bits being revoked. Per bug #6728 from Daniel German. Back-patch to all active branches, since this has been wrong since 8.0.
* Fix rescan logic in nodeCtescan.Tom Lane2012-08-15
| | | | | | | | | | | | | | | | | | | | | | The previous coding essentially assumed that nodes would be rescanned in the same order they were initialized in; or at least that the "leader" of a group of CTEscans would be rescanned before any others were required to execute. Unfortunately, that isn't even a little bit true. It's possible to devise queries in which the leader isn't rescanned until other CTEscans on the same CTE have run to completion, or even in which the leader never gets a rescan call at all. The fix makes the leader specially responsible only for initial creation and final destruction of the tuplestore; rescan resets are now a symmetrically shared responsibility. This means that we might reset the tuplestore multiple times when restarting a plan subtree containing multiple CTEscans; but resetting an already-empty tuplestore is cheap enough that that doesn't seem like a problem. Per report from Adam Mackler; the new regression test cases are based on his example query. Back-patch to 8.4 where CTE scans were introduced.
* Disallow extensions from owning the schema they are assigned to.Tom Lane2012-08-15
| | | | | | | | | | | This situation creates a dependency loop that confuses pg_dump and probably other things. Moreover, since the mental model is that the extension "contains" schemas it owns, but "is contained in" its extschema (even though neither is strictly true), having both true at once is confusing for people too. So prevent the situation from being set up. Reported and patched by Thom Brown. Back-patch to 9.1 where extensions were added.
* Prevent access to external files/URLs via XML entity references.Tom Lane2012-08-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | xml_parse() would attempt to fetch external files or URLs as needed to resolve DTD and entity references in an XML value, thus allowing unprivileged database users to attempt to fetch data with the privileges of the database server. While the external data wouldn't get returned directly to the user, portions of it could be exposed in error messages if the data didn't parse as valid XML; and in any case the mere ability to check existence of a file might be useful to an attacker. The ideal solution to this would still allow fetching of references that are listed in the host system's XML catalogs, so that documents can be validated according to installed DTDs. However, doing that with the available libxml2 APIs appears complex and error-prone, so we're not going to risk it in a security patch that necessarily hasn't gotten wide review. So this patch merely shuts off all access, causing any external fetch to silently expand to an empty string. A future patch may improve this. In HEAD and 9.2, also suppress warnings about undefined entities, which would otherwise occur as a result of not loading referenced DTDs. Previous branches don't show such warnings anyway, due to different error handling arrangements. Credit to Noah Misch for first reporting the problem, and for much work towards a solution, though this simplistic approach was not his preference. Also thanks to Daniel Veillard for consultation. Security: CVE-2012-3489
* Translation updatesPeter Eisentraut2012-08-14
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* Fix dependencies generated during ALTER TABLE ADD CONSTRAINT USING INDEX.Tom Lane2012-08-11
| | | | | | | | | | | | | | | | | | This command generated new pg_depend entries linking the index to the constraint and the constraint to the table, which match the entries made when a unique or primary key constraint is built de novo. However, it did not bother to get rid of the entries linking the index directly to the table. We had considered the issue when the ADD CONSTRAINT USING INDEX patch was written, and concluded that we didn't need to get rid of the extra entries. But this is wrong: ALTER COLUMN TYPE wasn't expecting such redundant dependencies to exist, as reported by Hubert Depesz Lubaczewski. On reflection it seems rather likely to break other things as well, since there are many bits of code that crawl pg_depend for one purpose or another, and most of them are pretty naive about what relationships they're expecting to find. Fortunately it's not that hard to get rid of the extra dependency entries, so let's do that. Back-patch to 9.1, where ALTER TABLE ADD CONSTRAINT USING INDEX was added.
* Fix upper limit of superuser_reserved_connections, add limit for wal_sendersMagnus Hagander2012-08-10
| | | | | | | | Should be limited to the maximum number of connections excluding autovacuum workers, not including. Add similar check for max_wal_senders, which should never be higher than max_connections.
* fsync backup_label after pg_start_backup()Simon Riggs2012-08-07
| | | | Dave Kerr, backpatched by Simon Riggs
* Fix bugs with parsing signed hh:mm and hh:mm:ss fields in interval input.Tom Lane2012-08-03
| | | | | | | | | | | | | | | | | | | | | | | DecodeInterval() failed to honor the "range" parameter (the special SQL syntax for indicating which fields appear in the literal string) if the time was signed. This seems inappropriate, so make it work like the not-signed case. The inconsistency was introduced in my commit f867339c0148381eb1d01f93ab5c79f9d10211de, which as noted in its log message was only really focused on making SQL-compliant literals work per spec. Including a sign here is not per spec, but if we're going to allow it then it's reasonable to expect it to work like the not-signed case. Also, remove bogus setting of tmask, which caused subsequent processing to think that what had been given was a timezone and not an hh:mm(:ss) field, thus confusing checks for redundant fields. This seems to be an aboriginal mistake in Lockhart's commit 2cf1642461536d0d8f3a1cf124ead0eac04eb760. Add regression test cases to illustrate the changed behaviors. Back-patch as far as 8.4, where support for spec-compliant interval literals was added. Range problem reported and diagnosed by Amit Kapila, tmask problem by me.
* Fix WITH attached to a nested set operation (UNION/INTERSECT/EXCEPT).Tom Lane2012-07-31
| | | | | | | | | | | | | Parse analysis neglected to cover the case of a WITH clause attached to an intermediate-level set operation; it only handled WITH at the top level or WITH attached to a leaf-level SELECT. Per report from Adam Mackler. In HEAD, I rearranged the order of SelectStmt's fields to put withClause with the other fields that can appear on non-leaf SelectStmts. In back branches, leave it alone to avoid a possible ABI break for third-party code. Back-patch to 8.4 where WITH support was added.
* Fix syslogger so that log_truncate_on_rotation works in the first rotation.Tom Lane2012-07-31
| | | | | | | | | | | | | | | In the original coding of the log rotation stuff, we did not bother to make the truncation logic work for the very first rotation after postmaster start (or after a syslogger crash and restart). It just always appended in that case. It did not seem terribly important at the time, but we've recently had two separate complaints from people who expected it to work unsurprisingly. (Both users tend to restart the postmaster about as often as a log rotation is configured to happen, which is maybe not typical use, but still...) Since the initial log file is opened in the postmaster, fixing this requires passing down some more state to the syslogger child process. It's always been like this, so back-patch to all supported branches.
* Only allow autovacuum to be auto-canceled by a directly blocked process.Tom Lane2012-07-26
| | | | | | | | | | | | | | | | | | | In the original coding of the autovacuum cancel feature, commit acac68b2bcae818bc8803b8cb8cbb17eee8d5e2b, an autovacuum process was considered a target for cancellation if it was found to hard-block any process examined in the deadlock search. This patch tightens the test so that the autovacuum must directly hard-block the current process. This should make the behavior more predictable in general, and in particular it ensures that an autovacuum will not be canceled with less than deadlock_timeout grace period. In the old coding, it was possible for an autovacuum to be canceled almost instantly, given unfortunate timing of two or more other processes' lock attempts. This also justifies the logging methodology in the recent commit d7318d43d891bd63e82dcfc27948113ed7b1db80; without this restriction, that patch isn't providing enough information to see the connection of the canceling process to the autovacuum. Like that one, patch all the way back.
* Log a better message when canceling autovacuum.Robert Haas2012-07-26
| | | | | | | | | | The old message was at DEBUG2, so typically it didn't show up in the log at all. As a result, in most cases where autovacuum was canceled, the only information that was logged was the table being vacuumed, with no indication as to what problem caused the cancel. Crank up the level to LOG and add some more details to assist with debugging. Back-patch all the way, per discussion on pgsql-hackers.
* Fix longstanding crash-safety bug with newly-created-or-reset sequences.Tom Lane2012-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a crash occurred immediately after the first nextval() call for a serial column, WAL replay would restore the sequence to a state in which it appeared that no nextval() had been done, thus allowing the first sequence value to be returned again by the next nextval() call; as reported in bug #6748 from Xiangming Mei. More generally, the problem would occur if an ALTER SEQUENCE was executed on a freshly created or reset sequence. (The manifestation with serial columns was introduced in 8.2 when we added an ALTER SEQUENCE OWNED BY step to serial column creation.) The cause is that sequence creation attempted to save one WAL entry by writing out a WAL record that made it appear that the first nextval() had already happened (viz, with is_called = true), while marking the sequence's in-database state with log_cnt = 1 to show that the first nextval() need not emit a WAL record. However, ALTER SEQUENCE would emit a new WAL entry reflecting the actual in-database state (with is_called = false). Then, nextval would allocate the first sequence value and set is_called = true, but it would trust the log_cnt value and not emit any WAL record. A crash at this point would thus restore the sequence to its post-ALTER state, causing the next nextval() call to return the first sequence value again. To fix, get rid of the idea of logging an is_called status different from reality. This means that the first nextval-driven WAL record will happen at the first nextval call not the second, but the marginal cost of that is pretty negligible. In addition, make sure that ALTER SEQUENCE resets log_cnt to zero in any case where it touches sequence parameters that affect future nextval results. This will result in some user-visible changes in the contents of a sequence's log_cnt column, as reflected in the patch's regression test changes; but no application should be depending on that anyway, since it was already true that log_cnt changes rather unpredictably depending on checkpoint timing. In addition, make some basically-cosmetic improvements to get rid of sequence.c's undesirable intimacy with page layout details. It was always really trying to WAL-log the contents of the sequence tuple, so we should have it do that directly using a HeapTuple's t_data and t_len, rather than backing into it with some magic assumptions about where the tuple would be on the sequence's page. Back-patch to all supported branches.
* 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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