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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.
* 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.
* 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.
* 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.
* 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.
* 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.)
* 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.)
* 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.
* 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.
* 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.
* 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.
* Move USE_WIDE_UPPER_LOWER define to c.h, and remove TS_USE_WIDE and useBruce Momjian2008-06-17
| | | | USE_WIDE_UPPER_LOWER instead.
* 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.
* Change xlog.h to xlogdefs.h in bufpage.h, and fix fallout.Alvaro Herrera2008-06-06
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* Fix pg_get_ruledef() so that negative numeric constants are parenthesized.Tom Lane2008-06-06
| | | | | | | | | | This is needed because :: casting binds more tightly than minus, so for example -1::integer is not the same as (-1)::integer, and there are cases where the difference is important. In particular this caused a failure in SELECT DISTINCT ... ORDER BY ... where expressions that should have matched were seen as different by the parser; but I suspect that there could be other cases where failure to parenthesize leads to subtler semantic differences in reloaded rules. Per report from Alexandr Popov.
* Alter the xxx_pattern_ops opclasses to use the regular equality operator ofTom Lane2008-05-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | the associated datatype as their equality member. This means that these opclasses can now support plain equality comparisons along with LIKE tests, thus avoiding the need for an extra index in some applications. This optimization was not possible when the pattern opclasses were first introduced, because we didn't insist that text equality meant bitwise equality; but we do now, so there is no semantic difference between regular and pattern equality operators. I removed the name_pattern_ops opclass altogether, since it's really useless: name's regular comparisons are just strcmp() and are unlikely to become something different. Instead teach indxpath.c that btree name_ops can be used for LIKE whether or not the locale is C. This might lead to a useful speedup in LIKE queries on the system catalogs in non-C locales. The ~=~ and ~<>~ operators are gone altogether. (It would have been nice to keep them for backward compatibility's sake, but since the pg_amop structure doesn't allow multiple equality operators per opclass, there's no way.) A not-immediately-obvious incompatibility is that the sort order within bpchar_pattern_ops indexes changes --- it had been identical to plain strcmp, but is now trailing-blank-insensitive. This will impact in-place upgrades, if those ever happen. Per discussions a couple months ago.
* Simplify code in formatting.c now that to upper/lower/initcase do notBruce Momjian2008-05-20
| | | | modify the passed string.
* Make to_char()'s localized month/day names depend on LC_TIME, not LC_MESSAGES.Tom Lane2008-05-19
| | | | Euler Taveira de Oliveira
* Coercion sanity check in ri_HashCompareOp failed to allow for enums, as perTom Lane2008-05-19
| | | | | example from Rod Taylor. On reflection the correct test here is for any polymorphic type, not specifically ANYARRAY as in the original coding.
* Extend GIN to support partial-match searches, and extend tsquery to supportTom Lane2008-05-16
| | | | | | prefix matching using this facility. Teodor Sigaev and Oleg Bartunov
* Add support for tracking call counts and elapsed runtime for user-definedTom Lane2008-05-15
| | | | | | | | | | functions. Note that because this patch changes FmgrInfo, any external C functions you might be testing with 8.4 will need to be recompiled. Patch by Martin Pihlak, some editorialization by me (principally, removing tracking of getrusage() numbers)
* Improve snapshot manager by keeping explicit track of snapshots.Alvaro Herrera2008-05-12
| | | | | | | | | | | | | There are two ways to track a snapshot: there's the "registered" list, which is used for arbitrary long-lived snapshots; and there's the "active stack", which is used for the snapshot that is considered "active" at any time. This also allows users of snapshots to stop worrying about snapshot memory allocation and freeing, and about using PG_TRY blocks around ActiveSnapshot assignment. This is all done automatically now. As a consequence, this allows us to reset MyProc->xmin when there are no more snapshots registered in the current backend, reducing the impact that long-running transactions have on VACUUM.
* Restructure some header files a bit, in particular heapam.h, by removing someAlvaro Herrera2008-05-12
| | | | | | | | | | | | unnecessary #include lines in it. Also, move some tuple routine prototypes and macros to htup.h, which allows removal of heapam.h inclusion from some .c files. For this to work, a new header file access/sysattr.h needed to be created, initially containing attribute numbers of system columns, for pg_dump usage. While at it, make contrib ltree, intarray and hstore header files more consistent with our header style.
* Adjust power() error messages to be more descriptive.Bruce Momjian2008-05-09
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* Update C comments to mention SQL:2003 handling of power return values.Bruce Momjian2008-05-09
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* Add regression test for various power expressions with a zero base, andBruce Momjian2008-05-08
| | | | adjust source code to be more modular.
* Have numeric 0 ^ 4.3 return 1, rather than an error, and have 0 ^ 0.0Bruce Momjian2008-05-08
| | | | | | return 1, rather than error. This was already the float8 behavior.
* Make the pg_stat_activity view call a SRF (pg_stat_get_activity())Magnus Hagander2008-05-07
| | | | | | | instead of calling a bunch of individual functions. This function can also be called directly, taking a PID as an argument, to return only the data for a single PID.
* Add timestamp and timestamptz versions of generate_series().Tom Lane2008-05-04
| | | | Hitoshi Harada
* Add pg_conf_load_time() function to report when the Postgres configurationTom Lane2008-05-04
| | | | | | files were last loaded. George Gensure
* Use new cstring/text conversion functions in some additional places.Tom Lane2008-05-04
| | | | | | | | These changes assume that the varchar and xml data types are represented the same as text. (I did not, however, accept the portions of the proposed patch that wanted to assume bytea is the same as text --- tgl.) Brendan Jurd
* The 8.2 patch that added support for an alias on the target table ofTom Lane2008-05-03
| | | | | UPDATE/DELETE forgot to teach ruleutils.c to display the alias. Per bug #4141 from Mathias Seiler.
* Add generate_subscripts, a series-generation function which generates anAlvaro Herrera2008-04-28
| | | | | | array's subscripts. Pavel Stehule, some editorialization by me.
* Allow float8, int8, and related datatypes to be passed by value on machinesTom Lane2008-04-21
| | | | | | | | | | where Datum is 8 bytes wide. Since this will break old-style C functions (those still using version 0 calling convention) that have arguments or results of these types, provide a configure option to disable it and retain the old pass-by-reference behavior. Likewise, provide a configure option to disable the recently-committed float4 pass-by-value change. Zoltan Boszormenyi, plus configurability stuff by me.
* Fix broken compare function for tsquery_ops. Per Tom's report.Teodor Sigaev2008-04-20
| | | | | | | | | | I never understood why initial authors GiST in pgsql choose so stgrange signature for 'same' method: bool *sameFn(Datum a, Datum b, bool* result) instead of simple, logical bool sameFn(Datum a, Datum b) This change will break any existing GiST extension, so we still live with it and will live.
* Re-enable pg_terminate_backend() using SIGTERM. SIGTERM testing stillBruce Momjian2008-04-17
| | | | needed.
* Revert addition of pg_terminate_backend() because of race conditions.Bruce Momjian2008-04-15
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* Add pg_terminate_backend() to allow terminating only a single session.Bruce Momjian2008-04-15
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* Push index operator lossiness determination down to GIST/GIN opclassTom Lane2008-04-14
| | | | | | | | | | | "consistent" functions, and remove pg_amop.opreqcheck, as per recent discussion. The main immediate benefit of this is that we no longer need 8.3's ugly hack of requiring @@@ rather than @@ to test weight-using tsquery searches on GIN indexes. In future it should be possible to optimize some other queries better than is done now, by detecting at runtime whether the index match is exact or not. Tom Lane, after an idea of Heikki's, and with some help from Teodor.
* Since createplan.c no longer cares whether index operators are lossy, it hasTom Lane2008-04-13
| | | | | | | | | | no particular need to do get_op_opfamily_properties() while building an indexscan plan. Postpone that lookup until executor start. This simplifies createplan.c a lot more than it complicates nodeIndexscan.c, and makes things more uniform since we already had to do it that way for RowCompare expressions. Should be a bit faster too, at least for plans that aren't re-used many times, since we avoid palloc'ing and perhaps copying the intermediate list data structure.
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