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* Reject out-of-range dates in to_date().Tom Lane2013-01-14
| | | | | | | | | Dates outside the supported range could be entered, but would not print reasonably, and operations such as conversion to timestamp wouldn't behave sanely either. Since this has the potential to result in undumpable table data, it seems worth back-patching. Hitoshi Harada
* Revert ill-considered change of index-size fudge factor.Tom Lane2013-01-11
| | | | | | | | | This partially reverts commit 21a39de5809cd3050a37d2554323cc1d0cbeed9d, restoring the pre-9.2 cost estimates for index usage. That change introduced much too large a bias against larger indexes, as per reports from Jeff Janes and others. The whole thing needs a rewrite, which I've done in HEAD, but the safest thing to do in 9.2 is just to undo this multiplier change.
* Fix potential corruption of lock table in CREATE/DROP INDEX CONCURRENTLY.Tom Lane2013-01-08
| | | | | | | | | | | | | | | | If VirtualXactLock() has to wait for a transaction that holds its VXID lock as a fast-path lock, it must first convert the fast-path lock to a regular lock. It failed to take the required "partition" lock on the main shared-memory lock table while doing so. This is the direct cause of the assert failure in GetLockStatusData() recently observed in the buildfarm, but more worryingly it could result in arbitrary corruption of the shared lock table if some other process were concurrently engaged in modifying the same partition of the lock table. Fortunately, VirtualXactLock() is only used by CREATE INDEX CONCURRENTLY and DROP INDEX CONCURRENTLY, so the opportunities for failure are fewer than they might have been. In passing, improve some comments and be a bit more consistent about order of operations.
* Invent a "one-shot" variant of CachedPlans for better performance.Tom Lane2013-01-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SPI_execute() and related functions create a CachedPlan, execute it once, and immediately discard it, so that the functionality offered by plancache.c is of no value in this code path. And performance measurements show that the extra data copying and invalidation checking done by plancache.c slows down simple queries by 10% or more compared to 9.1. However, enough of the SPI code is shared with functions that do need plan caching that it seems impractical to bypass plancache.c altogether. Instead, let's invent a variant version of cached plans that preserves 99% of the API but doesn't offer any of the actual functionality, nor the overhead. This puts SPI_execute() performance back on par, or maybe even slightly better, than it was before. This change should resolve recent complaints of performance degradation from Dong Ye, Pavel Stehule, and others. By avoiding data copying, this change also reduces the amount of memory needed to execute many-statement SPI_execute() strings, as for instance in a recent complaint from Tomas Vondra. An additional benefit of this change is that multi-statement SPI_execute() query strings are now processed fully serially, that is we complete execution of earlier statements before running parse analysis and planning on following ones. This eliminates a long-standing POLA violation, in that DDL that affects the behavior of a later statement will now behave as expected. Back-patch to 9.2, since this was a performance regression compared to 9.1. (In 9.2, place the added struct fields so as to avoid changing the offsets of existing fields.) Heikki Linnakangas and Tom Lane
* Tolerate timeline switches while "pg_basebackup -X fetch" is running.Heikki Linnakangas2013-01-03
| | | | | | | | | | | | | | | | | | | | | | If you take a base backup from a standby server with "pg_basebackup -X fetch", and the timeline switches while the backup is being taken, the backup used to fail with an error "requested WAL segment %s has already been removed". This is because the server-side code that sends over the required WAL files would not construct the WAL filename with the correct timeline after a switch. Fix that by using readdir() to scan pg_xlog for all the WAL segments in the range, regardless of timeline. Also, include all timeline history files in the backup, if taken with "-X fetch". That fixes another related bug: If a timeline switch happened just before the backup was initiated in a standby, the WAL segment containing the initial checkpoint record contains WAL from the older timeline too. Recovery will not accept that without a timeline history file that lists the older timeline. Backpatch to 9.2. Versions prior to that were not affected as you could not take a base backup from a standby before 9.2.
* Keep timeline history files restored from archive in pg_xlog.Heikki Linnakangas2012-12-30
| | | | | | | | | | | | | | | | | | | | | | | The cascading standby patch in 9.2 changed the way WAL files are treated when restored from the archive. Before, they were restored under a temporary filename, and not kept in pg_xlog, but after the patch, they were copied under pg_xlog. This is necessary for a cascading standby to find them, but it also means that if the archive goes offline and a standby is restarted, it can recover back to where it was using the files in pg_xlog. It also means that if you take an offline backup from a standby server, it includes all the required WAL files in pg_xlog. However, the same change was not made to timeline history files, so if the WAL segment containing the checkpoint record contains a timeline switch, you will still get an error if you try to restart recovery without the archive, or recover from an offline backup taken from the standby. With this patch, timeline history files restored from archive are copied into pg_xlog like WAL files are, so that pg_xlog contains all the files required to recover. This is a corner-case pre-existing issue in 9.2, but even more important in master where it's possible for a standby to follow a timeline switch through streaming replication. To make that possible, the timeline history files must be present in pg_xlog.
* Fix some minor issues in view pretty-printing.Tom Lane2012-12-24
| | | | | | | | Code review for commit 2f582f76b1945929ff07116cd4639747ce9bb8a1: don't use a static variable for what ought to be a deparse_context field, fix non-multibyte-safe test for spaces, avoid useless and potentially O(N^2) (though admittedly with a very small constant) calculations of wrap positions when we aren't going to wrap.
* Prevent failure when RowExpr or XmlExpr is parse-analyzed twice.Tom Lane2012-12-23
| | | | | | | | | | | | transformExpr() is required to cope with already-transformed expression trees, for various ugly-but-not-quite-worth-cleaning-up reasons. However, some of its newer subroutines hadn't gotten the memo. This accounts for bug #7763 from Norbert Buchmuller: transformRowExpr() was overwriting the previously determined type of a RowExpr during CREATE TABLE LIKE INCLUDING INDEXES. Additional investigation showed that transformXmlExpr had the same kind of problem, but all the other cases seem to be safe. Andres Freund and Tom Lane
* Fix race condition if a file is removed while pg_basebackup is running.Heikki Linnakangas2012-12-21
| | | | | | | | If a relation file was removed when the server-side counterpart of pg_basebackup was just about to open it to send it to the client, you'd get a "could not open file" error. Fix that. Backpatch to 9.1, this goes back to when pg_basebackup was introduced.
* Fix grammatical mistake in error messagePeter Eisentraut2012-12-20
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* Fix pg_extension_config_dump() to handle update cases more sanely.Tom Lane2012-12-20
| | | | | | | | | | | | | | | | | | | | | | If pg_extension_config_dump() is executed again for a table already listed in the extension's extconfig, the code was blindly making a new array entry. This does not seem useful. Fix it to replace the existing array entry instead, so that it's possible for extension update scripts to alter the filter conditions for configuration tables. In addition, teach ALTER EXTENSION DROP TABLE to check for an extconfig entry for the target table, and remove it if present. This is not a 100% solution because it's allowed for an extension update script to just summarily DROP a member table, and that code path doesn't go through ExecAlterExtensionContentsStmt. We could probably make that case clean things up if we had to, but it would involve sticking a very ugly wart somewhere in the guts of dependency.c. Since on the whole it seems quite unlikely that extension updates would want to remove pre-existing configuration tables, making the case possible with an explicit command seems sufficient. Per bug #7756 from Regina Obe. Back-patch to 9.1 where extensions were introduced.
* Fix recycling of WAL segments after changing recovery target timeline.Heikki Linnakangas2012-12-20
| | | | | | | | | | | | | | | | | | | | | | | | | After the recovery target timeline is changed, we would still recycle and preallocate WAL segments on the old target timeline. Those WAL segments created for the old timeline are a waste of space, although otherwise harmless. The problem is that when installing a recycled WAL segment as a future one, ThisTimeLineID is used to construct the filename. ThisTimeLineID is initialized in the checkpointer process to the recovery target timeline at startup, but it was not updated when the startup process chooses a new target timeline (recovery_target_timeline='latest'). To fix, always update ThisTimeLineID before recycling WAL segments at a restartpoint. This still leaves a small window where we might install WAL segments under wrong timeline ID, if the target timeline is changed just as we're about to start recycling. Also, when we're not on the target timeline yet, but still replaying some older timeline, we'll install WAL segments to the newer timeline anyway and they will still go wasted. We'll just live with the waste in that situation. Commit to 9.2 and 9.1. Older versions didn't change recovery target timeline after startup, and for master, I'll commit a slightly different variant of this.
* Check if we've reached end-of-backup point also if no redo is required.Heikki Linnakangas2012-12-19
| | | | | | | | | | | | | If you restored from a backup taken from a standby, and the last record in the backup is the checkpoint record, ie. there is no redo required except for the checkpoint record, we would fail to notice that we've reached the end-of-backup point, and the database is consistent. The result was an error "WAL ends before end of online backup". To fix, move the have-we-reached-end-of-backup check into CheckRecoveryConsistency(), which is already responsible for similar checks with minRecoveryPoint, and is called in the right places. Backpatch to 9.2, this check and bug did not exist before that.
* Fix failure to ignore leftover temp tables after a server crash.Tom Lane2012-12-17
| | | | | | | | | | | | | | | | | | | During crash recovery, we remove disk files belonging to temporary tables, but the system catalog entries for such tables are intentionally not cleaned up right away. Instead, the first backend that uses a temp schema is expected to clean out any leftover objects therein. This approach requires that we be careful to ignore leftover temp tables (since any actual access attempt would fail), *even if their BackendId matches our session*, if we have not yet established use of the session's corresponding temp schema. That worked fine in the past, but was broken by commit debcec7dc31a992703911a9953e299c8d730c778 which incorrectly removed the rd_islocaltemp relcache flag. Put it back, and undo various changes that substituted tests like "rel->rd_backend == MyBackendId" for use of a state-aware flag. Per trouble report from Heikki Linnakangas. Back-patch to 9.1 where the erroneous change was made. In the back branches, be careful to add rd_islocaltemp in a spot in the struct that was alignment padding before, so as not to break existing add-on code.
* Fix filling of postmaster.pid in bootstrap/standalone mode.Tom Lane2012-12-16
| | | | | | | | | | | | | | | | | | | | | | | We failed to ever fill the sixth line (LISTEN_ADDR), which caused the attempt to fill the seventh line (SHMEM_KEY) to fail, so that the shared memory key never got added to the file in standalone mode. This has been broken since we added more content to our lock files in 9.1. To fix, tweak the logic in CreateLockFile to add an empty LISTEN_ADDR line in standalone mode. This is a tad grotty, but since that function already knows almost everything there is to know about the contents of lock files, it doesn't seem that it's any better to hack it elsewhere. It's not clear how significant this bug really is, since a standalone backend should never have any children and thus it seems not critical to be able to check the nattch count of the shmem segment externally. But I'm going to back-patch the fix anyway. This problem had escaped notice because of an ancient (and in hindsight pretty dubious) decision to suppress LOG-level messages by default in standalone mode; so that the elog(LOG) complaint in AddToDataDirLockFile that should have warned of the problem didn't do anything. Fixing that is material for a separate patch though.
* In multi-insert, don't go into infinite loop on a huge tuple and fillfactor.Heikki Linnakangas2012-12-12
| | | | | | | | | | | | | | | | | | If a tuple is larger than page size minus space reserved for fillfactor, heap_multi_insert would never find a page that it fits in and repeatedly ask for a new page from RelationGetBufferForTuple. If a tuple is too large to fit on any page, taking fillfactor into account, RelationGetBufferForTuple will always expand the relation. In a normal insert, heap_insert will accept that and put the tuple on the new page. heap_multi_insert, however, does a fillfactor check of its own, and doesn't accept the newly-extended page RelationGetBufferForTuple returns, even though there is no other choice to make the tuple fit. Fix that by making the logic in heap_multi_insert more like the heap_insert logic. The first tuple is always put on the page RelationGetBufferForTuple gives us, and the fillfactor check is only applied to the subsequent tuples. Report from David Gould, although I didn't use his patch.
* Add defenses against integer overflow in dynahash numbuckets calculations.Tom Lane2012-12-11
| | | | | | | | | | | | | | | The dynahash code requires the number of buckets in a hash table to fit in an int; but since we calculate the desired hash table size dynamically, there are various scenarios where we might calculate too large a value. The resulting overflow can lead to infinite loops, division-by-zero crashes, etc. I (tgl) had previously installed some defenses against that in commit 299d1716525c659f0e02840e31fbe4dea3, but that covered only one call path. Moreover it worked by limiting the request size to work_mem, but in a 64-bit machine it's possible to set work_mem high enough that the problem appears anyway. So let's fix the problem at the root by installing limits in the dynahash.c functions themselves. Trouble report and patch by Jeff Davis.
* Consistency check should compare last record replayed, not last record read.Heikki Linnakangas2012-12-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | EndRecPtr is the last record that we've read, but not necessarily yet replayed. CheckRecoveryConsistency should compare minRecoveryPoint with the last replayed record instead. This caused recovery to think it's reached consistency too early. Now that we do the check in CheckRecoveryConsistency correctly, we have to move the call of that function to after redoing a record. The current place, after reading a record but before replaying it, is wrong. In particular, if there are no more records after the one ending at minRecoveryPoint, we don't enter hot standby until one extra record is generated and read by the standby, and CheckRecoveryConsistency is called. These two bugs conspired to make the code appear to work correctly, except for the small window between reading the last record that reaches minRecoveryPoint, and replaying it. In the passing, rename recoveryLastRecPtr, which is the last record replayed, to lastReplayedEndRecPtr. This makes it slightly less confusing with replayEndRecPtr, which is the last record read that we're about to replay. Original report from Kyotaro HORIGUCHI, further diagnosis by Fujii Masao. Backpatch to 9.0, where Hot Standby subtly changed the test from "minRecoveryPoint < EndRecPtr" to "minRecoveryPoint <= EndRecPtr". The former works because where the test is performed, we have always read one more record than we've replayed.
* Update minimum recovery point on truncation.Heikki Linnakangas2012-12-10
| | | | | | | | | If a file is truncated, we must update minRecoveryPoint. Once a file is truncated, there's no going back; it would not be safe to stop recovery at a point earlier than that anymore. Per report from Kyotaro HORIGUCHI. Backpatch to 8.4. Before that, minRecoveryPoint was not updated during recovery at all.
* Fix assorted bugs in privileges-for-types patch.Tom Lane2012-12-09
| | | | | | | | Commit 729205571e81b4767efc42ad7beb53663e08d1ff added privileges on data types, but there were a number of oversights. The implementation of default privileges for types missed a few places, and pg_dump was utterly innocent of the whole concept. Per bug #7741 from Nathan Alden, and subsequent wider investigation.
* Fix intermittent crash in DROP INDEX CONCURRENTLY.Tom Lane2012-12-05
| | | | | | | | | | | | | | | When deleteOneObject closes and reopens the pg_depend relation, we must see to it that the relcache pointer held by the calling function (typically performMultipleDeletions) is updated. Usually the relcache entry is retained so that the pointer value doesn't change, which is why the problem had escaped notice ... but after a cache flush event there's no guarantee that the same memory will be reassigned. To fix, change the recursive functions' APIs so that we pass around a "Relation *" not just "Relation". Per investigation of occasional buildfarm failures. This is trivial to reproduce with -DCLOBBER_CACHE_ALWAYS, which points up the sad lack of any buildfarm member running that way on a regular basis.
* Ensure recovery pause feature doesn't pause unless users can connect.Tom Lane2012-12-05
| | | | | | | | | | | | | | | | | | | | | | | | | | If we're not in hot standby mode, then there's no way for users to connect to reset the recoveryPause flag, so we shouldn't pause. The code was aware of this but the test to see if pausing was safe was seriously inadequate: it wasn't paying attention to reachedConsistency, and besides what it was testing was that we could legally enter hot standby, not that we have done so. Get rid of that in favor of checking LocalHotStandbyActive, which because of the coding in CheckRecoveryConsistency is tantamount to checking that we have told the postmaster to enter hot standby. Also, move the recoveryPausesHere() call that reacts to asynchronous recoveryPause requests so that it's not in the middle of application of a WAL record. I put it next to the recoveryStopsHere() call --- in future those are going to need to interact significantly, so this seems like a good waystation. Also, don't bother trying to read another WAL record if we've already decided not to continue recovery. This was no big deal when the code was written originally, but now that reading a record might entail actions like fetching an archive file, it seems a bit silly to do it like that. Per report from Jeff Janes and subsequent discussion. The pause feature needs quite a lot more work, but this gets rid of some indisputable bugs, and seems safe enough to back-patch.
* Must not reach consistency before XLOG_BACKUP_RECORDSimon Riggs2012-12-05
| | | | | | | | | | When waiting for an XLOG_BACKUP_RECORD the minRecoveryPoint will be incorrect, so we must not declare recovery as consistent before we have seen the record. Major bug allowing recovery to end too early in some cases, allowing people to see inconsistent db. This patch to HEAD and 9.2, other fix required for 9.1 and 9.0 Simon Riggs and Andres Freund, bug report by Jeff Janes
* Avoid holding vmbuffer pin after VACUUM.Simon Riggs2012-12-03
| | | | | | | | | | | | During VACUUM if we pause to perform a cycle of index cleanup we drop the vmbuffer pin, so we should do the same thing when heap scan completes. This avoids holding vmbuffer pin across the main index cleanup in VACUUM, which could be minutes or hours longer than necessary for correctness. Bug report and suggested fix from Pavan Deolasee
* Translation updatesPeter Eisentraut2012-12-03
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* Don't advance checkPoint.nextXid near the end of a checkpoint sequence.Tom Lane2012-12-02
| | | | | | | | | | | | | | | | | | | | | | This reverts commit c11130690d6dca64267201a169cfb38c1adec5ef in favor of actually fixing the problem: namely, that we should never have been modifying the checkpoint record's nextXid at this point to begin with. The nextXid should match the state as of the checkpoint's logical WAL position (ie the redo point), not the state as of its physical position. It's especially bogus to advance it in some wal_levels and not others. In any case there is no need for the checkpoint record to carry the same nextXid shown in the XLOG_RUNNING_XACTS record just emitted by LogStandbySnapshot, as any replay operation will already have adopted that value as current. This fixes bug #7710 from Tarvi Pillessaar, and probably also explains bug #6291 from Daniel Farina, in that if a checkpoint were in progress at the instant of XID wraparound, the epoch bump would be lost as reported. (And, of course, these days there's at least a 50-50 chance of a checkpoint being in progress at any given instant.) Diagnosed by me and independently by Andres Freund. Back-patch to all branches supporting hot standby.
* XidEpoch++ if wraparound during checkpoint.Simon Riggs2012-12-02
| | | | | | | | | | | | | | | | If wal_level = hot_standby we update the checkpoint nextxid, though in the case where a wraparound occurred half-way through a checkpoint we would neglect updating the epoch also. Updating the nextxid is arguably the wrong thing to do, but changing that may introduce subtle bugs into hot standby startup, while updating the value doesn't cause any known bugs yet. Minimal fix now to HEAD and backbranches, wider fix later in HEAD. Bug reported in #6291 by Daniel Farina and slightly differently in Cause analysis and recommended fixes from Tom Lane and Andres Freund. Applied patch is minimal version of Andres Freund's work.
* Change test ExceptionalCondition to return voidAlvaro Herrera2012-11-30
| | | | Commit 81107282a changed it in assert.c, but overlooked this other file.
* Add missing buffer lock acquisition in GetTupleForTrigger().Tom Lane2012-11-30
| | | | | | | | | | | | | If we had not been holding buffer pin continuously since the tuple was initially fetched by the UPDATE or DELETE query, it would be possible for VACUUM or a page-prune operation to move the tuple while we're trying to copy it. This would result in a garbage "old" tuple value being passed to an AFTER ROW UPDATE or AFTER ROW DELETE trigger. The preconditions for this are somewhat improbable, and the timing constraints are very tight; so it's not so surprising that this hasn't been reported from the field, even though the bug has been there a long time. Problem found by Andres Freund. Back-patch to all active branches.
* Produce a more useful error message for over-length Unix socket paths.Tom Lane2012-11-29
| | | | | | | | | | | | | | The length of a socket path name is constrained by the size of struct sockaddr_un, and there's not a lot we can do about it since that is a kernel API. However, it would be a good thing if we produced an intelligible error message when the user specifies a socket path that's too long --- and getaddrinfo's standard API is too impoverished to do this in the natural way. So insert explicit tests at the places where we construct a socket path name. Now you'll get an error that makes sense and even tells you what the limit is, rather than something generic like "Non-recoverable failure in name resolution". Per trouble report from Jeremy Drake and a fix idea from Andrew Dunstan.
* Cleanup VirtualXact at end of Hot StandbySimon Riggs2012-11-29
| | | | Resolves bug 7572 reported by Daniele Varrazzo
* Correctly init fast path fields on PGPROCSimon Riggs2012-11-29
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* Fix assorted bugs in CREATE/DROP INDEX CONCURRENTLY.Tom Lane2012-11-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8cb53654dbdb4c386369eb988062d0bbb6de725e, which introduced DROP INDEX CONCURRENTLY, managed to break CREATE INDEX CONCURRENTLY via a poor choice of catalog state representation. The pg_index state for an index that's reached the final pre-drop stage was the same as the state for an index just created by CREATE INDEX CONCURRENTLY. This meant that the (necessary) change to make RelationGetIndexList ignore about-to-die indexes also made it ignore freshly-created indexes; which is catastrophic because the latter do need to be considered in HOT-safety decisions. Failure to do so leads to incorrect index entries and subsequently wrong results from queries depending on the concurrently-created index. To fix, make the final state be indisvalid = true and indisready = false, which is otherwise nonsensical. This is pretty ugly but we can't add another column without forcing initdb, and it's too late for that in 9.2. (There's a cleaner fix in HEAD.) In addition, change CREATE/DROP INDEX CONCURRENTLY so that the pg_index flag changes they make without exclusive lock on the index are made via heap_inplace_update() rather than a normal transactional update. The latter is not very safe because moving the pg_index tuple could result in concurrent SnapshotNow scans finding it twice or not at all, thus possibly resulting in index corruption. This is a pre-existing bug in CREATE INDEX CONCURRENTLY, which was copied into the DROP code. In addition, fix various places in the code that ought to check to make sure that the indexes they are manipulating are valid and/or ready as appropriate. These represent bugs that have existed since 8.2, since a failed CREATE INDEX CONCURRENTLY could leave a corrupt or invalid index behind, and we ought not try to do anything that might fail with such an index. Also fix RelationReloadIndexInfo to ensure it copies all the pg_index columns that are allowed to change after initial creation. Previously we could have been left with stale values of some fields in an index relcache entry. It's not clear whether this actually had any user-visible consequences, but it's at least a bug waiting to happen. In addition, do some code and docs review for DROP INDEX CONCURRENTLY; some cosmetic code cleanup but mostly addition and revision of comments. Portions of this need to be back-patched even further, but I'll work on that separately. Problem reported by Amit Kapila, diagnosis by Pavan Deolasee, fix by Tom Lane and Andres Freund.
* If we don't have a backup-end-location, don't claim we've reached it.Heikki Linnakangas2012-11-28
| | | | | | | | This was apparently a typo, which caused recovery to think that it immediately reached the end of backup, and allowed the database to start up too early. Reported by Jeff Janes. Backpatch to 9.2, where this code was introduced.
* Revert patch for taking fewer snapshots.Tom Lane2012-11-26
| | | | | | | | | | | | | This reverts commit d573e239f03506920938bf0be56c868d9c3416da, "Take fewer snapshots". While that seemed like a good idea at the time, it caused execution to use a snapshot that had been acquired before locking any of the tables mentioned in the query. This created user-visible anomalies that were not present in any prior release of Postgres, as reported by Tomas Vondra. While this whole area could do with a redesign (since there are related cases that have anomalies anyway), it doesn't seem likely that any future patch would be reasonably back-patchable; and we don't want 9.2 to exhibit a behavior that's subtly unlike either past or future releases. Hence, revert to prior code while we rethink the problem.
* Fix SELECT DISTINCT with index-optimized MIN/MAX on inheritance trees.Tom Lane2012-11-26
| | | | | | | | | | | | | | | | | | | | | In a query such as "SELECT DISTINCT min(x) FROM tab", the DISTINCT is pretty useless (there being only one output row), but nonetheless it shouldn't fail. But it could fail if "tab" is an inheritance parent, because planagg.c's code for fixing up equivalence classes after making the index-optimized MIN/MAX transformation wasn't prepared to find child-table versions of the aggregate expression. The least ugly fix seems to be to add an option to mutate_eclass_expressions() to skip child-table equivalence class members, which aren't used anymore at this stage of planning so it's not really necessary to fix them. Since child members are ignored in many cases already, it seems plausible for mutate_eclass_expressions() to have an option to ignore them too. Per bug #7703 from Maxim Boguk. Back-patch to 9.1. Although the same code exists before that, it cannot encounter child-table aggregates AFAICS, because the index optimization transformation cannot succeed on inheritance trees before 9.1 (for lack of MergeAppend).
* pg_stat_replication.sync_state was displayed incorrectly at page boundary.Heikki Linnakangas2012-11-23
| | | | | | | | | | | | | | XLogRecPtrIsInvalid() only checks the xrecoff field, which is correct when checking if a WAL record could legally begin at the given position, but WAL sending can legally be paused at a page boundary, in which case xrecoff is 0. Use XLByteEQ(..., InvalidXLogRecPtr) instead, which checks that both xlogid and xrecoff are 0. 9.3 doesn't have this problem because XLogRecPtr is now a single 64-bit integer, so XLogRecPtrIsInvalid() does the right thing. Apply to 9.2, and 9.1 where pg_stat_replication view was introduced. Kyotaro HORIGUCHI, reviewed by Fujii Masao.
* Avoid bogus "out-of-sequence timeline ID" errors in standby-mode.Heikki Linnakangas2012-11-22
| | | | | | | | | | | | | | | | | | When startup process opens a WAL segment after replaying part of it, it validates the first page on the WAL segment, even though the page it's really interested in later in the file. As part of the validation, it checks that the TLI on the page header is >= the TLI it saw on the last page it read. If the segment contains a timeline switch, and we have already replayed it, and then re-open the WAL segment (because of streaming replication got disconnected and reconnected, for example), the TLI check will fail when the first page is validated. Fix that by relaxing the TLI check when re-opening a WAL segment. Backpatch to 9.0. Earlier versions had the same code, but before standby mode was introduced in 9.0, recovery never tried to re-read a segment after partially replaying it. Reported by Amit Kapila, while testing a new feature.
* Don't launch new child processes after we've been told to shut down.Tom Lane2012-11-21
| | | | | | | | | | | | | | | | | | | | | | | Once we've received a shutdown signal (SIGINT or SIGTERM), we should not launch any more child processes, even if we get signals requesting such. The normal code path for spawning backends has always understood that, but the postmaster's infrastructure for hot standby and autovacuum didn't get the memo. As reported by Hari Babu in bug #7643, this could lead to failure to shut down at all in some cases, such as when SIGINT is received just before the startup process sends PMSIGNAL_RECOVERY_STARTED: we'd launch a bgwriter and checkpointer, and then those processes would have no idea that they ought to quit. Similarly, launching a new autovacuum worker would result in waiting till it finished before shutting down. Also, switch the order of the code blocks in reaper() that detect startup process crash versus shutdown termination. Once we've sent it a signal, we should not consider that exit(1) is surprising. This is just a cosmetic fix since shutdown occurs correctly anyway, but better not to log a phony complaint about startup process crash. Back-patch to 9.0. Some parts of this might be applicable before that, but given the lack of prior complaints I'm not going to worry too much about older branches.
* Improve handling of INT_MIN / -1 and related cases.Tom Lane2012-11-19
| | | | | | | | | | | | | | | Some platforms throw an exception for this division, rather than returning a necessarily-overflowed result. Since we were testing for overflow after the fact, an exception isn't nice. We can avoid the problem by treating division by -1 as negation. Add some regression tests so that we'll find out if any compilers try to optimize away the overflow check conditions. Back-patch of commit 1f7cb5c30983752ff8de833de30afcaee63536d0. Per discussion with Xi Wang, though this is different from the patch he submitted.
* Limit values of archive_timeout, post_auth_delay, auth_delay.milliseconds.Tom Lane2012-11-18
| | | | | | | | | | | | | | | The previous definitions of these GUC variables allowed them to range up to INT_MAX, but in point of fact the underlying code would suffer overflows or other errors with large values. Reduce the maximum values to something that won't misbehave. There's no apparent value in working harder than this, since very large delays aren't sensible for any of these. (Note: the risk with archive_timeout is that if we're late checking the state, the timestamp difference it's being compared to might overflow. So we need some amount of slop; the choice of INT_MAX/2 is arbitrary.) Per followup investigation of bug #7670. Although this isn't a very significant fix, might as well back-patch.
* Fix syslogger to not fail when log_rotation_age exceeds 2^31 milliseconds.Tom Lane2012-11-18
| | | | | | | | | | | | | We need to avoid calling WaitLatch with timeouts exceeding INT_MAX. Fortunately a simple clamp will do the trick, since no harm is done if the wait times out before it's really time to rotate the log file. Per bug #7670 (probably bug #7545 is the same thing, too). In passing, fix bogus definition of log_rotation_age's maximum value in guc.c --- it was numerically right, but only because MINS_PER_HOUR and SECS_PER_MINUTE have the same value. Back-patch to 9.2. Before that, syslogger wasn't using WaitLatch.
* Improve check_partial_indexes() to consider join clauses in proof attempts.Tom Lane2012-11-15
| | | | | | | | | | | | | | | | Traditionally check_partial_indexes() has only looked at restriction clauses while trying to prove partial indexes usable in queries. However, join clauses can also be used in some cases; mainly, that a strict operator on "x" proves an "x IS NOT NULL" index predicate, even if the operator is in a join clause rather than a restriction clause. Adding this code fixes a regression in 9.2, because previously we would take join clauses into account when considering whether a partial index could be used in a nestloop inner indexscan path. 9.2 doesn't handle nestloop inner indexscans in the same way, and this consideration was overlooked in the rewrite. Moving the work to check_partial_indexes() is a better solution anyway, since the proof applies whether or not we actually use the index in that particular way, and we don't have to do it over again for each possible outer relation. Per report from Dave Cramer.
* Fix the int8 and int2 cases of (minimum possible integer) % (-1).Tom Lane2012-11-14
| | | | | | | | | | | | | | The correct answer for this (or any other case with arg2 = -1) is zero, but some machines throw a floating-point exception instead of behaving sanely. Commit f9ac414c35ea084ff70c564ab2c32adb06d5296f dealt with this in int4mod, but overlooked the fact that it also happens in int8mod (at least on my Linux x86_64 machine). Protect int2mod as well; it's not clear whether any machines fail there (mine does not) but since the test is so cheap it seems better safe than sorry. While at it, simplify the original guard in int4mod: we need only check for arg2 == -1, we don't need to check arg1 explicitly. Xi Wang, with some editing by me.
* Fix memory leaks in record_out() and record_send().Tom Lane2012-11-13
| | | | | | | | | | | | | | | | | | | | | record_out() leaks memory: it fails to free the strings returned by the per-column output functions, and also is careless about detoasted values. This results in a query-lifespan memory leakage when returning composite values to the client, because printtup() runs the output functions in the query-lifespan memory context. Fix it to handle these issues the same way printtup() does. Also fix a similar leakage in record_send(). (At some point we might want to try to run output functions in shorter-lived memory contexts, so that we don't need a zero-leakage policy for them. But that would be a significantly more invasive patch, which doesn't seem like material for back-patching.) In passing, use appendStringInfoCharMacro instead of appendStringInfoChar in the innermost data-copying loop of record_out, to try to shave a few cycles from this function's runtime. Per trouble report from Carlos Henrique Reimer. Back-patch to all supported versions.
* Skip searching for subxact locks at commit.Simon Riggs2012-11-13
| | | | | | | | At commit all standby locks are released for the top-level transaction, so searching for locks for each subtransaction is both pointless and costly (N^2) in the presence of many AccessExclusiveLocks.
* Clarify docs on hot standby lock releaseSimon Riggs2012-11-13
| | | | Andres Freund and Simon Riggs
* Fix multiple problems in WAL replay.Tom Lane2012-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most of the replay functions for WAL record types that modify more than one page failed to ensure that those pages were locked correctly to ensure that concurrent queries could not see inconsistent page states. This is a hangover from coding decisions made long before Hot Standby was added, when it was hardly necessary to acquire buffer locks during WAL replay at all, let alone hold them for carefully-chosen periods. The key problem was that RestoreBkpBlocks was written to hold lock on each page restored from a full-page image for only as long as it took to update that page. This was guaranteed to break any WAL replay function in which there was any update-ordering constraint between pages, because even if the nominal order of the pages is the right one, any mixture of full-page and non-full-page updates in the same record would result in out-of-order updates. Moreover, it wouldn't work for situations where there's a requirement to maintain lock on one page while updating another. Failure to honor an update ordering constraint in this way is thought to be the cause of bug #7648 from Daniel Farina: what seems to have happened there is that a btree page being split was rewritten from a full-page image before the new right sibling page was written, and because lock on the original page was not maintained it was possible for hot standby queries to try to traverse the page's right-link to the not-yet-existing sibling page. To fix, get rid of RestoreBkpBlocks as such, and instead create a new function RestoreBackupBlock that restores just one full-page image at a time. This function can be invoked by WAL replay functions at the points where they would otherwise perform non-full-page updates; in this way, the physical order of page updates remains the same no matter which pages are replaced by full-page images. We can then further adjust the logic in individual replay functions if it is necessary to hold buffer locks for overlapping periods. A side benefit is that we can simplify the handling of concurrency conflict resolution by moving that code into the record-type-specfic functions; there's no more need to contort the code layout to keep conflict resolution in front of the RestoreBkpBlocks call. In connection with that, standardize on zero-based numbering rather than one-based numbering for referencing the full-page images. In HEAD, I removed the macros XLR_BKP_BLOCK_1 through XLR_BKP_BLOCK_4. They are still there in the header files in previous branches, but are no longer used by the code. In addition, fix some other bugs identified in the course of making these changes: spgRedoAddNode could fail to update the parent downlink at all, if the parent tuple is in the same page as either the old or new split tuple and we're not doing a full-page image: it would get fooled by the LSN having been advanced already. This would result in permanent index corruption, not just transient failure of concurrent queries. Also, ginHeapTupleFastInsert's "merge lists" case failed to mark the old tail page as a candidate for a full-page image; in the worst case this could result in torn-page corruption. heap_xlog_freeze() was inconsistent about using a cleanup lock or plain exclusive lock: it did the former in the normal path but the latter for a full-page image. A plain exclusive lock seems sufficient, so change to that. Also, remove gistRedoPageDeleteRecord(), which has been dead code since VACUUM FULL was rewritten. Back-patch to 9.0, where hot standby was introduced. Note however that 9.0 had a significantly different WAL-logging scheme for GIST index updates, and it doesn't appear possible to make that scheme safe for concurrent hot standby queries, because it can leave inconsistent states in the index even between WAL records. Given the lack of complaints from the field, we won't work too hard on fixing that branch.
* Check for stack overflow in transformSetOperationTree().Tom Lane2012-11-11
| | | | | | | | | | | | | | Since transformSetOperationTree() recurses, it can be driven to stack overflow with enough UNION/INTERSECT/EXCEPT clauses in a query. Add a check to ensure it fails cleanly instead of crashing. Per report from Matthew Gerber (though it's not clear whether this is the only thing going wrong for him). Historical note: I think the reasoning behind not putting a check here in the beginning was that the check in transformExpr() ought to be sufficient to guard the whole parser. However, because transformSetOperationTree() recurses all the way to the bottom of the set-operation tree before doing any analysis of the statement's expressions, that check doesn't save it.
* Fix WaitLatch() to return promptly when the requested timeout expires.Tom Lane2012-11-08
| | | | | | | | | | | | | | | | If the sleep is interrupted by a signal, we must recompute the remaining time to wait; otherwise, a steady stream of non-wait-terminating interrupts could delay return from WaitLatch indefinitely. This has been shown to be a problem for the autovacuum launcher, and there may well be other places now or in the future with similar issues. So we'd better make the function robust, even though this'll add at least one gettimeofday call per wait. Back-patch to 9.2. We might eventually need to fix 9.1 as well, but the code is quite different there, and the usage of WaitLatch in 9.1 is so limited that it's not clearly important to do so. Reported and diagnosed by Jeff Janes, though I rewrote his patch rather heavily.