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* Don't assume that a tuple's header size is unchanged during toasting.Tom Lane2011-11-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This assumption can be wrong when the toaster is passed a raw on-disk tuple, because the tuple might pre-date an ALTER TABLE ADD COLUMN operation that added columns without rewriting the table. In such a case the tuple's natts value is smaller than what we expect from the tuple descriptor, and so its t_hoff value could be smaller too. In fact, the tuple might not have a null bitmap at all, and yet our current opinion of it is that it contains some trailing nulls. In such a situation, toast_insert_or_update did the wrong thing, because to save a few lines of code it would use the old t_hoff value as the offset where heap_fill_tuple should start filling data. This did not leave enough room for the new nulls bitmap, with the result that the first few bytes of data could be overwritten with null flag bits, as in a recent report from Hubert Depesz Lubaczewski. The particular case reported requires ALTER TABLE ADD COLUMN followed by CREATE TABLE AS SELECT * FROM ... or INSERT ... SELECT * FROM ..., and further requires that there be some out-of-line toasted fields in one of the tuples to be copied; else we'll not reach the troublesome code. The problem can only manifest in this form in 8.4 and later, because before commit a77eaa6a95009a3441e0d475d1980259d45da072, CREATE TABLE AS or INSERT/SELECT wouldn't result in raw disk tuples getting passed directly to heap_insert --- there would always have been at least a junkfilter in between, and that would reconstitute the tuple header with an up-to-date t_natts and hence t_hoff. But I'm backpatching the tuptoaster change all the way anyway, because I'm not convinced there are no older code paths that present a similar risk.
* Move user functions related to WAL into xlogfuncs.cSimon Riggs2011-11-04
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* Fix inline_set_returning_function() to allow multiple OUT parameters.Tom Lane2011-11-03
| | | | | | | | inline_set_returning_function failed to distinguish functions returning generic RECORD (which require a column list in the RTE, as well as run-time type checking) from those with multiple OUT parameters (which do not). This prevented inlining from happening. Per complaint from Jay Levitt. Back-patch to 8.4 where this capability was introduced.
* Do not treat a superuser as a member of every role for HBA purposes.Andrew Dunstan2011-11-03
| | | | | | This makes it possible to use reject lines with group roles. Andrew Dunstan, reviewd by Robert Haas.
* Support range data types.Heikki Linnakangas2011-11-03
| | | | | | | Selectivity estimation functions are missing for some range type operators, which is a TODO. Jeff Davis
* Fix handling of PlaceHolderVars in nestloop parameter management.Tom Lane2011-11-03
| | | | | | | | | | | | | If we use a PlaceHolderVar from the outer relation in an inner indexscan, we need to reference the PlaceHolderVar as such as the value to be passed in from the outer relation. The previous code effectively tried to reconstruct the PHV from its component expression, which doesn't work since (a) the Vars therein aren't necessarily bubbled up far enough, and (b) it would be the wrong semantics anyway because of the possibility that the PHV is supposed to have gone to null at some point before the current join. Point (a) led to "variable not found in subplan target list" planner errors, but point (b) would have led to silently wrong answers. Per report from Roger Niederland.
* Avoid scanning nulls at the beginning of a btree index scan.Tom Lane2011-11-02
| | | | | | | | | | | If we have an inequality key that constrains the other end of the index, it doesn't directly help us in doing the initial positioning ... but it does imply a NOT NULL constraint on the index column. If the index stores nulls at this end, we can use the implied NOT NULL condition for initial positioning, just as if it had been stated explicitly. This avoids wasting time when there are a lot of nulls in the column. This is the reverse of the examples given in bugs #6278 and #6283, which were about failing to stop early when we encounter nulls at the end of the indexscan.
* Fix btree stop-at-nulls logic properly.Tom Lane2011-11-02
| | | | | | | | | | | | As pointed out by Naoya Anzai, my previous try at this was a few bricks shy of a load, because I had forgotten that the initial-positioning logic might not try to skip over nulls at the end of the index the scan will start from. We ought to fix that, because it represents an unnecessary inefficiency, but first let's get the scan-stop logic back to a safe state. With this patch, we preserve the performance benefit requested in bug #6278 for the case of scanning forward into NULLs (in a NULLS LAST index), but the reverse case of scanning backward across NULLs when there's no suitable initial-positioning qual is still inefficient.
* Update more comments about checkpoints being done by bgwriterSimon Riggs2011-11-02
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* Reduce checkpoints and WAL traffic on low activity database serverSimon Riggs2011-11-02
| | | | | | | | | | | | Previously, we skipped a checkpoint if no WAL had been written since last checkpoint, though this does not appear in user documentation. As of now, we skip a checkpoint until we have written at least one enough WAL to switch the next WAL file. This greatly reduces the level of activity and number of WAL messages generated by a very low activity server. This is safe because the purpose of a checkpoint is to act as a starting place for a recovery, in case of crash. This patch maintains minimal WAL volume for replay in case of crash, thus maintaining very low crash recovery time.
* Refactor xlog.c to create src/backend/postmaster/startup.cSimon Riggs2011-11-02
| | | | | Startup process now has its own dedicated file, just like all other special/background processes. Reduces role and size of xlog.c
* Derive oldestActiveXid at correct time for Hot Standby.Simon Riggs2011-11-02
| | | | | | | | | There was a timing window between when oldestActiveXid was derived and when it should have been derived that only shows itself under heavy load. Move code around to ensure correct timing of derivation. No change to StartupSUBTRANS() code, which is where this failed. Bug report by Chris Redekop
* Start Hot Standby faster when initial snapshot is incomplete.Simon Riggs2011-11-02
| | | | | | | | | If the initial snapshot had overflowed then we can start whenever the latest snapshot is empty, not overflowed or as we did already, start when the xmin on primary was higher than xmax of our starting snapshot, which proves we have full snapshot data. Bug report by Chris Redekop
* Remove spurious entry from missed catch while patch jugglingSimon Riggs2011-11-02
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* Fix timing of Startup CLOG and MultiXact during Hot StandbySimon Riggs2011-11-02
| | | | Patch by me, bug report by Chris Redekop, analysis by Florian Pflug
* Initialize myProcLocks queues just once, at postmaster startup.Robert Haas2011-11-01
| | | | | | | In assert-enabled builds, we assert during the shutdown sequence that the queues have been properly emptied, and during process startup that we are inheriting empty queues. In non-assert enabled builds, we just save a few cycles.
* Preserve Var location information during flatten_join_alias_vars.Tom Lane2011-11-01
| | | | | | | This allows us to give correct syntax error pointers when complaining about ungrouped variables in a join query with aggregates or GROUP BY. It's pretty much irrelevant for the planner's use of the function, though perhaps it might aid debugging sometimes.
* Fix race condition with toast table access from a stale syscache entry.Tom Lane2011-11-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a tuple in a syscache contains an out-of-line toasted field, and we try to fetch that field shortly after some other transaction has committed an update or deletion of the tuple, there is a race condition: vacuum could come along and remove the toast tuples before we can fetch them. This leads to transient failures like "missing chunk number 0 for toast value NNNNN in pg_toast_2619", as seen in recent reports from Andrew Hammond and Tim Uckun. The design idea of syscache is that access to stale syscache entries should be prevented by relation-level locks, but that fails for at least two cases where toasted fields are possible: ANALYZE updates pg_statistic rows without locking out sessions that might want to plan queries on the same table, and CREATE OR REPLACE FUNCTION updates pg_proc rows without any meaningful lock at all. The least risky fix seems to be an idea that Heikki suggested when we were dealing with a related problem back in August: forcibly detoast any out-of-line fields before putting a tuple into syscache in the first place. This avoids the problem because at the time we fetch the parent tuple from the catalog, we should be holding an MVCC snapshot that will prevent removal of the toast tuples, even if the parent tuple is outdated immediately after we fetch it. (Note: I'm not convinced that this statement holds true at every instant where we could be fetching a syscache entry at all, but it does appear to hold true at the times where we could fetch an entry that could have a toasted field. We will need to be a bit wary of adding toast tables to low-level catalogs that don't have them already.) An additional benefit is that subsequent uses of the syscache entry should be faster, since they won't have to detoast the field. Back-patch to all supported versions. The problem is significantly harder to reproduce in pre-9.0 releases, because of their willingness to flush every entry in a syscache whenever the underlying catalog is vacuumed (cf CatalogCacheFlushRelation); but there is still a window for trouble.
* Clean up whitespace and indentation in parser and scanner filesPeter Eisentraut2011-11-01
| | | | These are not touched by pgindent, so clean them up a bit manually.
* Comment changes to show bgwriter no longer performs checkpoints.Simon Riggs2011-11-01
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* Have checkpointer send stats once each processing loop.Simon Riggs2011-11-01
| | | | Noted by Fujii Masao
* Add new file for checkpointer.cSimon Riggs2011-11-01
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* Split work of bgwriter between 2 processes: bgwriter and checkpointer.Simon Riggs2011-11-01
| | | | | | | | | | | | | bgwriter is now a much less important process, responsible for page cleaning duties only. checkpointer is now responsible for checkpoints and so has a key role in shutdown. Later patches will correct doc references to the now old idea that bgwriter performs checkpoints. Has beneficial effect on performance at high write rates, but mainly refactoring to more easily allow changes for power reduction by simplifying previously tortuous code around required to allow page cleaning and checkpointing to time slice in the same process. Patch by me, Review by Dickson Guedes
* Stop btree indexscans upon reaching nulls in either direction.Tom Lane2011-10-31
| | | | | | | | | | | The existing scan-direction-sensitive tests were overly complex, and failed to stop the scan in cases where it's perfectly legitimate to do so. Per bug #6278 from Maksym Boguk. Back-patch to 8.3, which is as far back as the patch applies easily. Doesn't seem worth sweating over a relatively minor performance issue in 8.2 at this late date. (But note that this was a performance regression from 8.1 and before, so 8.2 is being left as an outlier.)
* Support more locale-specific formatting options in cash_out().Tom Lane2011-10-30
| | | | | | | | | | | | | | | The POSIX spec defines locale fields for controlling the ordering of the value, sign, and currency symbol in monetary output, but cash_out only supported a small subset of these options. Fully implement p/n_sign_posn, p/n_cs_precedes, and p/n_sep_by_space per spec. Fix up cash_in so that it will accept all these format variants. Also, make sure that thousands_sep is only inserted to the left of the decimal point, as required by spec. Per bug #6144 from Eduard Kracmar and discussion of bug #6277. This patch includes some ideas from Alexander Lakhin's proposed patch, though it is very different in detail.
* Further improvement of make_greater_string.Tom Lane2011-10-30
| | | | | | | | | Make sure that it considers all the possibilities that the old code did, instead of trying only one possibility per character position. To keep the runtime in bounds, instead tweak the character incrementers to not try every possible multibyte character code. Remove unnecessary logic to restore the old character value on failure. Additional comment and formatting cleanup.
* Update visibilitymap.c header comments.Robert Haas2011-10-29
| | | | Recent work on index-only scans left this somewhat out of date.
* Fix assorted bogosities in cash_in() and cash_out().Tom Lane2011-10-29
| | | | | | | | | | | | | cash_out failed to handle multiple-byte thousands separators, as per bug #6277 from Alexander Law. In addition, cash_in didn't handle that either, nor could it handle multiple-byte positive_sign. Both routines failed to support multiple-byte mon_decimal_point, which I did not think was worth changing, but at least now they check for the possibility and fall back to using '.' rather than emitting invalid output. Also, make cash_in handle trailing negative signs, which formerly it would reject. Since cash_out generates trailing negative signs whenever the locale tells it to, this last omission represents a fail-to-reload-dumped-data bug. IMO that justifies patching this all the way back.
* Improve make_greater_string() with encoding-specific incrementers.Robert Haas2011-10-29
| | | | | | | | | This infrastructure doesn't in any way guarantee that the character we produce will sort before the one we incremented; but it does at least make it much more likely that we'll end up with something that is a valid character, which improves our chances. Kyotaro Horiguchi, with various adjustments by me.
* Allow hint bits to be set sooner for temporary and unlogged tables.Robert Haas2011-10-28
| | | | | | | | | | | We need not wait until the commit record is durably on disk, because in the event of a crash the page we're updating with hint bits will be gone anyway. Per off-list report from Heikki Linnakangas, this can significantly degrade the performance of unlogged tables; I was able to show a 2x speedup from this patch on a pgbench run with scale factor 15. In practice, this will mostly help small, heavily updated tables, because on larger tables you're unlikely to run into the same row again before the commit record makes it out to disk.
* Fix the number of lwlocks needed by the "fast path" lock patch. It needsHeikki Linnakangas2011-10-27
| | | | | | | | one lock per backend or auxiliary process - the need for a lock for each aux processes was not accounted for in NumLWLocks(). No-one noticed, because the three locks needed for the three aux processes fit into the few extra lwlocks we allocate for 3rd party modules that don't call RequestAddinLWLocks() (NUM_USER_DEFINED_LWLOCKS, 4 by default).
* Improve planner's ability to recognize cases where an IN's RHS is unique.Tom Lane2011-10-26
| | | | | | | | | | | | If the right-hand side of a semijoin is unique, then we can treat it like a normal join (or another way to say that is: we don't need to explicitly unique-ify the data before doing it as a normal join). We were recognizing such cases when the RHS was a sub-query with appropriate DISTINCT or GROUP BY decoration, but there's another way: if the RHS is a plain relation with unique indexes, we can check if any of the indexes prove the output is unique. Most of the infrastructure for that was there already in the join removal code, though I had to rearrange it a bit. Per reflection about a recent example in pgsql-performance.
* Change FK trigger naming convention to fix self-referential FKs.Tom Lane2011-10-26
| | | | | | | | | | | Use names like "RI_ConstraintTrigger_a_NNNN" for FK action triggers and "RI_ConstraintTrigger_c_NNNN" for FK check triggers. This ensures the action trigger fires first in self-referential cases where the very same row update fires both an action and a check trigger. This change provides a non-probabilistic solution for bug #6268, at the risk that it could break client code that is making assumptions about the exact names assigned to auto-generated FK triggers. Hence, change this in HEAD only. No need for forced initdb since old triggers continue to work fine.
* Change FK trigger creation order to better support self-referential FKs.Tom Lane2011-10-26
| | | | | | | | | | | | | | | | | | | | | | | | | | When a foreign-key constraint references another column of the same table, row updates will queue both the PK's ON UPDATE action and the FK's CHECK action in the same event. The ON UPDATE action must execute first, else the CHECK will check a non-final state of the row and possibly throw an inappropriate error, as seen in bug #6268 from Roman Lytovchenko. Now, the firing order of multiple triggers for the same event is determined by the sort order of their pg_trigger.tgnames, and the auto-generated names we use for FK triggers are "RI_ConstraintTrigger_NNNN" where NNNN is the trigger OID. So most of the time the firing order is the same as creation order, and so rearranging the creation order fixes it. This patch will fail to fix the problem if the OID counter wraps around or adds a decimal digit (eg, from 99999 to 100000) while we are creating the triggers for an FK constraint. Given the small odds of that, and the low usage of self-referential FKs, we'll live with that solution in the back branches. A better fix is to change the auto-generated names for FK triggers, but it seems unwise to do that in stable branches because there may be client code that depends on the naming convention. We'll fix it that way in HEAD in a separate patch. Back-patch to all supported branches, since this bug has existed for a long time.
* Make event_source visible on all platformsMagnus Hagander2011-10-25
| | | | | | On non-windows platform, we just ignore any value set there. Noted by Jaime Casanova
* Support configurable eventlog application names on WindowsMagnus Hagander2011-10-25
| | | | | | | | This allows different instances to use the eventlog with different identifiers, by setting the event_source GUC, similar to how syslog_ident works. Original patch by MauMau, heavily modified by Magnus Hagander
* Don't trust deferred-unique indexes for join removal.Tom Lane2011-10-23
| | | | | | | | | | | The uniqueness condition might fail to hold intra-transaction, and assuming it does can give incorrect query results. Per report from Marti Raudsepp, though this is not his proposed patch. Back-patch to 9.0, where both these features were introduced. In the released branches, add the new IndexOptInfo field to the end of the struct, to try to minimize ABI breakage for third-party code that may be examining that struct.
* Support synchronization of snapshots through an export/import procedure.Tom Lane2011-10-22
| | | | | | | | | | | | | | A transaction can export a snapshot with pg_export_snapshot(), and then others can import it with SET TRANSACTION SNAPSHOT. The data does not leave the server so there are not security issues. A snapshot can only be imported while the exporting transaction is still running, and there are some other restrictions. I'm not totally convinced that we've covered all the bases for SSI (true serializable) mode, but it works fine for lesser isolation modes. Joachim Wieland, reviewed by Marko Tiikkaja, and rather heavily modified by Tom Lane
* Fix overly-complicated usage of errcode_for_file_access().Heikki Linnakangas2011-10-22
| | | | | | | No need to do "errcode(errcode_for_file_access())", just "errcode_for_file_access()" is enough. The extra errcode() call is useless but harmless, so there's no user-visible bug here. Nevertheless, backpatch to 9.1 where this code were added.
* Code review for pgstat_get_crashed_backend_activity patch.Tom Lane2011-10-21
| | | | | | | Avoid possibly dumping core when pgstat_track_activity_query_size has a less-than-default value; avoid uselessly searching for the query string of a successfully-exited backend; don't bother putting out an ERRDETAIL if we don't have a query to show; some other minor stylistic improvements.
* More cleanup after failed reduced-lock-levels-for-DDL feature.Tom Lane2011-10-21
| | | | | | | | | | | | | | | | Turns out that use of ShareUpdateExclusiveLock or ShareRowExclusiveLock to protect DDL changes had gotten copied into several places that were not touched by either of Simon's original patches for the feature, and thus neither he nor I thought to revert them. (Indeed, it appears that two of these uses were committed *after* the reversion, which just goes to show that git merging is no panacea.) Change these places to use AccessExclusiveLock again. If we ever manage to resurrect that feature, we're going to have to think a bit harder about how to keep lock level usage in sync for DDL operations that aren't within the AlterTable infrastructure. Two of these bugs are only in HEAD, but one is in the 9.1 branch too. Alvaro found one of them, I found the other two.
* Try to log current the query string when a backend crashes.Robert Haas2011-10-21
| | | | | | | | | | | | | | | | To avoid minimize risk inside the postmaster, we subject this feature to a number of significant limitations. We very much wish to avoid doing any complex processing inside the postmaster, due to the posssibility that the crashed backend has completely corrupted shared memory. To that end, no encoding conversion is done; instead, we just replace anything that doesn't look like an ASCII character with a question mark. We limit the amount of data copied to 1024 characters, and carefully sanity check the source of that data. While these restrictions would doubtless be unacceptable in a general-purpose logging facility, even this limited facility seems like an improvement over the status quo ante. Marti Raudsepp, reviewed by PDXPUG and myself
* Fix DROP OPERATOR FAMILY IF EXISTS.Robert Haas2011-10-21
| | | | | | | | | | Essentially, the "IF EXISTS" portion was being ignored, and an error thrown anyway if the opfamily did not exist. I broke this in commit fd1843ff8979c0461fb3f1a9eab61140c977e32d; so backpatch to 9.1.X. Report and diagnosis by KaiGai Kohei.
* Simplify and improve ProcessStandbyHSFeedbackMessage logic.Tom Lane2011-10-20
| | | | | | | | | | | | | | There's no need to clamp the standby's xmin to be greater than GetOldestXmin's result; if there were any such need this logic would be hopelessly inadequate anyway, because it fails to account for within-database versus cluster-wide values of GetOldestXmin. So get rid of that, and just rely on sanity-checking that the xmin is not wrapped around relative to the nextXid counter. Also, don't reset the walsender's xmin if the current feedback xmin is indeed out of range; that just creates more problems than we already had. Lastly, don't bother to take the ProcArrayLock; there's no need to do that to set xmin. Also improve the comments about this in GetOldestXmin itself.
* Fix get_object_namespace() not to think extensions are "in" a schema.Robert Haas2011-10-20
| | | | | | | extnamespace means something altogether different in this context. Mostly by accident, this coding error (introduced in my commit 82a4a777d94bec965ab2f1d04b6e6a3f0447b377) broke the buildfarm instead of just silently doing the wrong thing.
* Add "skipping" to the NOTICE produced by DROP OPERATOR CLASS IF EXISTS.Robert Haas2011-10-19
| | | | | | | This makes this message consistent with all the other similar notices produced by other DROP IF EXISTS commands. Noted by KaiGai Kohei
* Consolidate DROP handling for some object types.Robert Haas2011-10-19
| | | | | | | This gets rid of a significant amount of duplicative code. KaiGai Kohei, reviewed in earlier versions by Dimitri Fontaine, with further review and cleanup by me.
* Suppress -Wunused-result warnings about write() and fwrite().Tom Lane2011-10-18
| | | | | | | This is merely an exercise in satisfying pedants, not a bug fix, because in every case we were checking for failure later with ferror(), or else there was nothing useful to be done about a failure anyway. Document the latter cases.
* Reject empty pg_hba.conf files.Tom Lane2011-10-18
| | | | | | | | | | | An empty HBA file is surely an error, since it means there is no way to connect to the server. We've not heard identifiable reports of people actually doing that, but this will also close off the case Thom Brown just complained of, namely pointing hba_file at a directory. (On at least some platforms with some directories, it will read as an empty file.) Perhaps this should be back-patched, but given the lack of previous complaints, I won't add extra work for the translators.
* Exclude postmaster.opts from base backupsMagnus Hagander2011-10-18
| | | | Noted by Fujii Masao
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