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* Arrange to convert EXISTS subqueries that are equivalent to hashable INTom Lane2008-08-22
| | | | | | | | | | | | | | | | | | | | | | | subqueries into the same thing you'd have gotten from IN (except always with unknownEqFalse = true, so as to get the proper semantics for an EXISTS). I believe this fixes the last case within CVS HEAD in which an EXISTS could give worse performance than an equivalent IN subquery. The tricky part of this is that if the upper query probes the EXISTS for only a few rows, the hashing implementation can actually be worse than the default, and therefore we need to make a cost-based decision about which way to use. But at the time when the planner generates plans for subqueries, it doesn't really know how many times the subquery will be executed. The least invasive solution seems to be to generate both plans and postpone the choice until execution. Therefore, in a query that has been optimized this way, EXPLAIN will show two subplans for the EXISTS, of which only one will actually get executed. There is a lot more that could be done based on this infrastructure: in particular it's interesting to consider switching to the hash plan if we start out using the non-hashed plan but find a lot more upper rows going by than we expected. I have therefore left some minor inefficiencies in place, such as initializing both subplans even though we will currently only use one.
* Cause the output from debug_print_parse, debug_print_rewritten, andTom Lane2008-08-19
| | | | | | | | debug_print_plan to appear at LOG message level, not DEBUG1 as historically. Make debug_pretty_print default to on. Also, cause plans generated via EXPLAIN to be subject to debug_print_plan. This is all to make debug_print_plan a reasonably comfortable substitute for the former behavior of EXPLAIN VERBOSE.
* Clean up the loose ends in selectivity estimation left by my patch for semiTom Lane2008-08-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | and anti joins. To do this, pass the SpecialJoinInfo struct for the current join as an additional optional argument to operator join selectivity estimation functions. This allows the estimator to tell not only what kind of join is being formed, but which variable is on which side of the join; a requirement long recognized but not dealt with till now. This also leaves the door open for future improvements in the estimators, such as accounting for the null-insertion effects of lower outer joins. I didn't do anything about that in the current patch but the information is in principle deducible from what's passed. The patch also clarifies the definition of join selectivity for semi/anti joins: it's the fraction of the left input that has (at least one) match in the right input. This allows getting rid of some very fuzzy thinking that I had committed in the original 7.4-era IN-optimization patch. There's probably room to estimate this better than the present patch does, but at least we know what to estimate. Since I had to touch CREATE OPERATOR anyway to allow a variant signature for join estimator functions, I took the opportunity to add a couple of additional checks that were missing, per my recent message to -hackers: * Check that estimator functions return float8; * Require execute permission at the time of CREATE OPERATOR on the operator's function as well as the estimator functions; * Require ownership of any pre-existing operator that's modified by the command. I also moved the lookup of the functions out of OperatorCreate() and into operatorcmds.c, since that seemed more consistent with most of the other catalog object creation processes, eg CREATE TYPE.
* Make the temporary directory for pgstat files configurable by the GUCMagnus Hagander2008-08-15
| | | | | | | | variable stats_temp_directory, instead of requiring the admin to mount/symlink the pg_stat_tmp directory manually. For now the config variable is PGC_POSTMASTER. Room for further improvment that would allow it to be changed on-the-fly.
* Implement SEMI and ANTI joins in the planner and executor. (Semijoins replaceTom Lane2008-08-14
| | | | | | | | | | | | | | the old JOIN_IN code, but antijoins are new functionality.) Teach the planner to convert appropriate EXISTS and NOT EXISTS subqueries into semi and anti joins respectively. Also, LEFT JOINs with suitable upper-level IS NULL filters are recognized as being anti joins. Unify the InClauseInfo and OuterJoinInfo infrastructure into "SpecialJoinInfo". With that change, it becomes possible to associate a SpecialJoinInfo with every join attempt, which permits some cleanup of join selectivity estimation. That needs to be taken much further than this patch does, but the next step is to change the API for oprjoin selectivity functions, which seems like material for a separate patch. So for the moment the output size estimates for semi and especially anti joins are quite bogus.
* Introduce the concept of relation forks. An smgr relation can now consistHeikki Linnakangas2008-08-11
| | | | | | | | | | | | | | | | of multiple forks, and each fork can be created and grown separately. The bulk of this patch is about changing the smgr API to include an extra ForkNumber argument in every smgr function. Also, smgrscheduleunlink and smgrdounlink no longer implicitly call smgrclose, because other forks might still exist after unlinking one. The callers of those functions have been modified to call smgrclose instead. This patch in itself doesn't have any user-visible effect, but provides the infrastructure needed for upcoming patches. The additional forks envisioned are a rewritten FSM implementation that doesn't rely on a fixed-size shared memory block, and a visibility map to allow skipping portions of a table in VACUUM that have no dead tuples.
* Fix corner-case bug introduced with HOT: if REINDEX TABLE pg_class (or aTom Lane2008-08-10
| | | | | | | | | | | | REINDEX DATABASE including same) is done before a session has done any other update on pg_class, the pg_class relcache entry was left with an incorrect setting of rd_indexattr, because the indexed-attributes set would be first demanded at a time when we'd forced a partial list of indexes into the pg_class entry, and it would remain cached after that. This could result in incorrect decisions about HOT-update safety later in the same session. In practice, since only pg_class_relname_nsp_index would be missed out, only ALTER TABLE RENAME and ALTER TABLE SET SCHEMA could trigger a problem. Per report and test case from Ondrej Jirman.
* Rearrange the querytree representation of ORDER BY/GROUP BY/DISTINCT itemsTom Lane2008-08-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | as per my recent proposal: 1. Fold SortClause and GroupClause into a single node type SortGroupClause. We were already relying on them to be struct-equivalent, so using two node tags wasn't accomplishing much except to get in the way of comparing items with equal(). 2. Add an "eqop" field to SortGroupClause to carry the associated equality operator. This is cheap for the parser to get at the same time it's looking up the sort operator, and storing it eliminates the need for repeated not-so-cheap lookups during planning. In future this will also let us represent GROUP/DISTINCT operations on datatypes that have hash opclasses but no btree opclasses (ie, they have equality but no natural sort order). The previous representation simply didn't work for that, since its only indicator of comparison semantics was a sort operator. 3. Add a hasDistinctOn boolean to struct Query to explicitly record whether the distinctClause came from DISTINCT or DISTINCT ON. This allows removing some complicated and not 100% bulletproof code that attempted to figure that out from the distinctClause alone. This patch doesn't in itself create any new capability, but it's necessary infrastructure for future attempts to use hash-based grouping for DISTINCT and UNION/INTERSECT/EXCEPT.
* Add a few more DTrace probes to the backend.Alvaro Herrera2008-08-01
| | | | Robert Lor
* Replace the hard-wired type knowledge in TypeCategory() and IsPreferredType()Tom Lane2008-07-30
| | | | | | | | | | | | | | | | | | | | | with system catalog lookups, as was foreseen to be necessary almost since their creation. Instead put the information into two new pg_type columns, typcategory and typispreferred. Add support for setting these when creating a user-defined base type. The category column is just a "char" (i.e. a poor man's enum), allowing a crude form of user extensibility of the category list: just use an otherwise-unused character. This seems sufficient for foreseen uses, but we could upgrade to having an actual category catalog someday, if there proves to be a huge demand for custom type categories. In this patch I have attempted to hew exactly to the behavior of the previous hardwired logic, except for introducing new type categories for arrays, composites, and enums. In particular the default preferred state for user-defined types remains TRUE. That seems worth revisiting, but it should be done as a separate patch from introducing the infrastructure. Likewise, any adjustment of the standard set of categories should be done separately.
* Use guc.c's parse_int() instead of pg_atoi() to parse fillfactor inTom Lane2008-07-23
| | | | | | | | | | default_reloptions(). The previous coding was really a bug because pg_atoi() will always throw elog on bad input data, whereas default_reloptions is not supposed to complain about bad input unless its validate parameter is true. Right now you could only expose the problem by hand-modifying pg_class.reloptions into an invalid state, so it doesn't seem worth back-patching; but we should get it right in HEAD because there might be other situations in future. Noted while studying GIN fast-update patch.
* Code review for array_fill patch: fix inadequate check for array size overflowTom Lane2008-07-21
| | | | | | and bogus documentation (dimension arrays are int[] not anyarray). Also the errhint() messages seem to be really errdetail(), since there is nothing heuristic about them. Some other trivial cosmetic improvements.
* Adjust things so that the query_string of a cached plan and the sourceText ofTom Lane2008-07-18
| | | | | | | | | | | | | | | | | | | | | | | | a portal are never NULL, but reliably provide the source text of the query. It turns out that there was only one place that was really taking a short-cut, which was the 'EXECUTE' utility statement. That doesn't seem like a sufficiently critical performance hotspot to justify not offering a guarantee of validity of the portal source text. Fix it to copy the source text over from the cached plan. Add Asserts in the places that set up cached plans and portals to reject null source strings, and simplify a bunch of places that formerly needed to guard against nulls. There may be a few places that cons up statements for execution without having any source text at all; I found one such in ConvertTriggerToFK(). It seems sufficient to inject a phony source string in such a case, for instance ProcessUtility((Node *) atstmt, "(generated ALTER TABLE ADD FOREIGN KEY command)", NULL, false, None_Receiver, NULL); We should take a second look at the usage of debug_query_string, particularly the recently added current_query() SQL function. ITAGAKI Takahiro and Tom Lane
* Implement SQL-spec RETURNS TABLE syntax for functions.Tom Lane2008-07-18
| | | | | | | (Unlike the original submission, this patch treats TABLE output parameters as being entirely equivalent to OUT parameters -- tgl) Pavel Stehule
* Add a "provariadic" column to pg_proc to eliminate the remarkably expensiveTom Lane2008-07-16
| | | | | | | | | | need to deconstruct proargmodes for each pg_proc entry inspected by FuncnameGetCandidates(). Fixes function lookup performance regression caused by yesterday's variadic-functions patch. In passing, make pg_proc.probin be NULL, rather than a dummy value '-', in cases where it is not actually used for the particular type of function. This should buy back some of the space cost of the extra column.
* Support "variadic" functions, which can accept a variable number of argumentsTom Lane2008-07-16
| | | | | | | | | | | | | | so long as all the trailing arguments are of the same (non-array) type. The function receives them as a single array argument (which is why they have to all be the same type). It might be useful to extend this facility to aggregates, but this patch doesn't do that. This patch imposes a noticeable slowdown on function lookup --- a follow-on patch will fix that by adding a redundant column to pg_proc. Pavel Stehule
* Add array_fill() to create arrays initialized with a value.Bruce Momjian2008-07-16
| | | | Pavel Stehule
* Const-ify the arguments of str_tolower() and friends to suppress compileTom Lane2008-07-12
| | | | | | | | warnings. Clean up various unneeded cruft that was left behind after creating those routines. Introduce some convenience functions str_tolower_z etc to eliminate tedious and error-prone double arguments in formatting.c. (Currently there seems no need to export the latter, but maybe reconsider this later.)
* Make sure we only try to free snapshots that have been passed throughAlvaro Herrera2008-07-11
| | | | | | | CopySnapshot, per Neil Conway. Also add a comment about the assumption in GetSnapshotData that the argument is statically allocated. Also, fix some more typos in comments in snapmgr.c.
* Fix a few typos in comments in snapmgr.c, and sort header inclusionsNeil Conway2008-07-11
| | | | alphabetically.
* Add unchangeable GUC "variables" segment_size, wal_block_size, andTom Lane2008-07-10
| | | | | | wal_segment_size to make those configuration parameters available to clients, in the same way that block_size was previously exposed. Bernd Helmle, with comments from Abhijit Menon-Sen and some further tweaking by me.
* Increase PG_SYSLOG_LIMIT (the max line length sent to syslog()) from 128 toTom Lane2008-07-09
| | | | | | | | 1024 to improve performance when sending large elog messages. Also add a comment about why we use that number. Since this represents an externally visible behavior change, and might possibly result in portability issues, it seems best not to back-patch it.
* Fix performance bug in write_syslog(): the code to preferentially break theTom Lane2008-07-08
| | | | | | | | | | log message at newlines cost O(N^2) for very long messages with few or no newlines. For messages in the megabyte range this became the dominant cost. Per gripe from Achilleas Mantzios. Patch all the way back, since this is a safe change with no portability risks. I am also thinking of increasing PG_SYSLOG_LIMIT, but that should be done separately.
* Add comment for deadlock_timeout:Bruce Momjian2008-07-08
| | | | /* This is PGC_SIGHUP so all backends have the same value. */
* Fix estimate_num_groups() to assume that GROUP BY expressions yielding booleanTom Lane2008-07-07
| | | | | | | | | results always contribute two groups, regardless of the expression contents. This is very substantially more accurate than the regular heuristic for certain boolean tests like "col IS NULL". Per gripe from Sam Mason. Back-patch to all supported releases, since the behavior of estimate_num_groups() hasn't changed all that much since 7.4.
* Fix AT TIME ZONE (in all three variants) so that we first try to interpretTom Lane2008-07-07
| | | | | | | | | | | | | | | | the timezone argument as a timezone abbreviation, and only try it as a full timezone name if that fails. The zic database has four zones (CET, EET, MET, WET) that are full daylight-savings zones and yet have names that are the same as their abbreviations for standard time, resulting in ambiguity. In the timestamp input functions we resolve the ambiguity by preferring the abbreviation, and AT TIME ZONE should work the same way. (No functionality is lost because the zic database also has other names for these zones, eg Europe/Zurich.) Per gripe from Jaromir Talir. Backpatch to 8.1. Older releases did not have the issue because AT TIME ZONE only accepted abbreviations not zone names. (Thus, this patch also arguably fixes a compatibility botch introduced at 8.1: in ambiguous cases we now behave the same as 8.0 did.)
* Prevent integer overflows during units conversion when displaying a GUCTom Lane2008-07-06
| | | | | | | | | | | | variable that has units. Per report from Stefan Kaltenbrunner. Backport to 8.2. I also backported my patch of 2007-06-21 that prevented comparable overflows on the input side, since that now seems to have enough field track record to be back-patched safely. That patch included addition of hints listing the available unit names, which I did not bother to strip out of it --- this will make a little more work for the translators, but they can copy the translation from 8.3, and anyway an untranslated hint is better than no hint.
* Add a function pg_get_keywords() to let clients find out the set of keywordsTom Lane2008-07-03
| | | | known to the SQL parser. Dave Page
* Fix transaction-lifespan memory leak in xpath(). Report by Matt Magoffin,Tom Lane2008-07-03
| | | | fix by Kris Jurka.
* Remove GUC extra_desc strings that are redundant with the enum value lists.Tom Lane2008-07-01
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* "debug" level was supposed to be hidden, since it's just an alias for debug2.Magnus Hagander2008-07-01
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* Split apart message_level_options into one set for server-side settings andMagnus Hagander2008-07-01
| | | | | | one for client-side, restoring the previous behaviour with different sort order for the 'log' level. Also, remove redundant list of available options, since the enum code will output it automatically.
* Fix recovery.conf boolean variables to take the same range of stringBruce Momjian2008-06-30
| | | | values as postgresql.conf.
* Turn PGBE_ACTIVITY_SIZE into a GUC variable, track_activity_query_size.Heikki Linnakangas2008-06-30
| | | | | | | | | As the buffer could now be a lot larger than before, and copying it could thus be a lot more expensive than before, use strcpy instead of memcpy to copy the query string, as was already suggested in comments. Also, only copy the PgBackendStatus struct and string if the slot is in use. Patch by Thomas Lee, with some changes by me.
* If pnstrdup is going to be promoted to a generally available function,Tom Lane2008-06-28
| | | | it ought to conform to the rest of palloc.h in using Size for sizes.
* Fix bug "select lower('asd') = 'asd'" returns false with multibyte encodingTeodor Sigaev2008-06-26
| | | | | and non-C locale. Fix is just to use correct source's length for char2wchar call.
* Reduce the alignment requirement of type "name" from int to char, and arrangeTom Lane2008-06-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | to suppress zero-padding of "name" entries in indexes. The alignment change is unlikely to save any space, but it is really needed anyway to make the world safe for our widespread practice of passing plain old C strings to functions that are declared as taking Name. In the previous coding, the C compiler was entitled to assume that a Name pointer was word-aligned; but we were failing to guarantee that. I think the reason we'd not seen failures is that usually the only thing that gets done with such a pointer is strcmp(), which is hard to optimize in a way that exploits word-alignment. Still, some enterprising compiler guy will probably think of a way eventually, or we might change our code in a way that exposes more-obvious optimization opportunities. The padding change is accomplished in one-liner fashion by declaring the "name" index opclasses to use storage type "cstring" in pg_opclass.h. Normally btree and hash don't allow a nondefault storage type, because they don't have any provisions for converting the input datum to another type. However, because name and cstring are effectively the same thing except for padding, no conversion is needed --- we only need index_form_tuple() to treat the datum as being cstring not name, and this is sufficient. This seems to make for about a one-third reduction in the typical sizes of system catalog indexes that involve "name" columns, of which we have many. These two changes are only weakly related, but the alignment change makes me feel safer that the padding change won't introduce problems, so I'm committing them together.
* Merge duplicate upper/lower/initcap() routines in oracle_compat.c andBruce Momjian2008-06-23
| | | | | formatting.c to use common code; remove duplicate functions and support routines that are no longer needed.
* Fix Gen_fmgrtab.sh to not rely on hard-wired knowledge of the column numbersTom Lane2008-06-23
| | | | | | | | | | | | | | in pg_proc. Also make it not emit duplicate extern declarations, and make it a bit more bulletproof in some other small ways. Likewise fix the equally hard-wired, and utterly undocumented, knowledge in the MSVC build scripts. For testing purposes and perhaps other uses in future, pull out that portion of the MSVC scripts into a standalone perl script equivalent to Gen_fmgrtab.sh, and make it generate actually identical output, rather than just more-or-less-the-same output. Motivated by looking at Pavel's variadic function patch. Whether or not that gets accepted, we can be sure that pg_proc's column set will change again in the future; it's time to not have to deal with this gotcha.
* Rewrite the sinval messaging mechanism to reduce contention and avoidTom Lane2008-06-19
| | | | | | | | | | | | | | | | | | | | | | | | | | unnecessary cache resets. The major changes are: * When the queue overflows, we only issue a cache reset to the specific backend or backends that still haven't read the oldest message, rather than resetting everyone as in the original coding. * When we observe backend(s) falling well behind, we signal SIGUSR1 to only one backend, the one that is furthest behind and doesn't already have a signal outstanding for it. When it finishes catching up, it will in turn signal SIGUSR1 to the next-furthest-back guy, if there is one that is far enough behind to justify a signal. The PMSIGNAL_WAKEN_CHILDREN mechanism is removed. * We don't attempt to clean out dead messages after every message-receipt operation; rather, we do it on the insertion side, and only when the queue fullness passes certain thresholds. * Split SInvalLock into SInvalReadLock and SInvalWriteLock so that readers don't block writers nor vice versa (except during the infrequent queue cleanout operations). * Transfer multiple sinval messages for each acquisition of a read or write lock.
* Improve our #include situation by moving pointer types away from theAlvaro Herrera2008-06-19
| | | | | | | corresponding struct definitions. This allows other headers to avoid including certain highly-loaded headers such as rel.h and relscan.h, instead using just relcache.h, heapam.h or genam.h, which are more lightweight and thus cause less unnecessary dependencies.
* Fix compiler warning introduced by recent patch. Tsk tsk.Tom Lane2008-06-18
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* Move wchar2char() and char2wchar() from tsearch into /mb to be easier toBruce Momjian2008-06-18
| | | | | | use for other modules; also move pnstrdup(). Clean up code slightly.
* Clean up some problems with redundant cross-type arithmetic operators. AddTom Lane2008-06-17
| | | | | | | | | | | | | int2-and-int8 implementations of the basic arithmetic operators +, -, *, /. This doesn't really add any new functionality, but it avoids "operator is not unique" failures that formerly occurred in these cases because the parser couldn't decide whether to promote the int2 to int4 or int8. We could alternatively have removed the existing cross-type operators, but experimentation shows that the cost of an additional type coercion expression node is noticeable compared to such cheap operators; so let's not give up any performance here. On the other hand, I removed the int2-and-int4 modulo (%) operators since they didn't seem as important from a performance standpoint. Per a complaint last January from ykhuang.
* Add URL for introduction to multibyte programming in C.Bruce Momjian2008-06-17
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* Move USE_WIDE_UPPER_LOWER define to c.h, and remove TS_USE_WIDE and useBruce Momjian2008-06-17
| | | | USE_WIDE_UPPER_LOWER instead.
* Refactor XLogOpenRelation() and XLogReadBuffer() in preparation for relationHeikki Linnakangas2008-06-12
| | | | | | | | | | forks. XLogOpenRelation() and the associated light-weight relation cache in xlogutils.c is gone, and XLogReadBuffer() now takes a RelFileNode as argument, instead of Relation. For functions that still need a Relation struct during WAL replay, there's a new function called CreateFakeRelcacheEntry() that returns a fake entry like XLogOpenRelation() used to.
* Fix spelling mistake in postgresql.conf.Bruce Momjian2008-06-11
| | | | Greg Sabino Mullane
* Fix unportable (and incorrect anyway) usage of LL constant suffix thatTom Lane2008-06-09
| | | | recently snuck into cash.c. Per report from Edmundo Robles Lopez.
* Fix datetime input functions to correctly detect integer overflow whenTom Lane2008-06-09
| | | | | running on a 64-bit platform ... strtol() will happily return 64-bit output in that case. Per bug #4231 from Geoff Tolley.