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* Support set-returning functions in the target lists of Agg and Group planTom Lane2008-09-08
| | | | | | nodes. This is a pretty ugly feature but since we don't yet have a plausible substitute, we'd better support it everywhere. Per gripe from Jeff Davis.
* Move exprType(), exprTypmod(), expression_tree_walker(), and related routinesTom Lane2008-08-25
| | | | | | into nodes/nodeFuncs, so as to reduce wanton cross-subsystem #includes inside the backend. There's probably more that should be done along this line, but this is a start anyway.
* Get rid of the last remaining uses of var_is_rel(), to wit some debuggingTom Lane2008-08-25
| | | | | | | | | checks in ExecIndexBuildScanKeys() that were inadequate anyway: it's better to verify the correct varno on an expected index key, not just reject OUTER and INNER. This makes the entire current contents of nodeFuncs.c dead code. I'll be replacing it with some other stuff later, as per recent proposal.
* 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.
* Performance fix for new anti-join code in nodeMergejoin.c: after finding aTom Lane2008-08-15
| | | | | | | | | | | | | | | | | | match in antijoin mode, we should advance to next outer tuple not next inner. We know we don't want to return this outer tuple, and there is no point in advancing over matching inner tuples now, because we'd just have to do it again if the next outer tuple has the same merge key. This makes a noticeable difference if there are lots of duplicate keys in both inputs. Similarly, after finding a match in semijoin mode, arrange to advance to the next outer tuple after returning the current match; or immediately, if it fails the extra quals. The rationale is the same. (This is a performance bug in existing releases; perhaps worth back-patching? The planner tries to avoid using mergejoin with lots of duplicates, so it may not be a big issue in practice.) Nestloop and hash got this right to start with, but I made some cosmetic adjustments there to make the corresponding bits of logic look more similar.
* 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.
* Install checks in executor startup to ensure that the tuples produced by anTom Lane2008-08-08
| | | | | | | | | | | | INSERT or UPDATE will match the target table's current rowtype. In pre-8.3 releases inconsistency can arise with stale cached plans, as reported by Merlin Moncure. (We patched the equivalent hazard on the SELECT side in Feb 2007; I'm not sure why we thought there was no risk on the insertion side.) In 8.3 and HEAD this problem should be impossible due to plan cache invalidation management, but it seems prudent to make the check anyway. Back-patch as far as 8.0. 7.x versions lack ALTER COLUMN TYPE, so there seems no way to abuse a stale plan comparably.
* Improve INTERSECT/EXCEPT hashing by realizing that we don't need to make anyTom Lane2008-08-07
| | | | | | | | | hashtable entries for tuples that are found only in the second input: they can never contribute to the output. Furthermore, this implies that the planner should endeavor to put first the smaller (in number of groups) input relation for an INTERSECT. Implement that, and upgrade prepunion's estimation of the number of rows returned by setops so that there's some amount of sanity in the estimate of which one is smaller.
* Support hashing for duplicate-elimination in INTERSECT and EXCEPT queries.Tom Lane2008-08-07
| | | | | | | | | | This completes my project of improving usage of hashing for duplicate elimination (aggregate functions with DISTINCT remain undone, but that's for some other day). As with the previous patches, this means we can INTERSECT/EXCEPT on datatypes that can hash but not sort, and it means that INTERSECT/EXCEPT without ORDER BY are no longer certain to produce sorted output.
* Do not allow Unique nodes to be scanned backwards. The code claimed that itTom Lane2008-08-05
| | | | | | | would work, but in fact it didn't return the same rows when moving backwards as when moving forwards. This would have no visible effect in a DISTINCT query (at least assuming the column datatypes use a strong definition of equality), but it gave entirely wrong answers for DISTINCT ON queries.
* 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.
* As noted by Andrew Gierth, there's really no need any more to force a junkTom Lane2008-07-26
| | | | | | | | | | | | | | | | filter to be used when INSERT or SELECT INTO has a plan that returns raw disk tuples. The virtual-tuple-slot optimizations that were put in place awhile ago mean that ExecInsert has to do ExecMaterializeSlot, and that already copies the tuple if it's raw (and does so more efficiently than a junk filter, too). So get rid of that logic. This in turn means that we can throw away ExecMayReturnRawTuples, which wasn't used for any other purpose, and was always a kluge anyway. In passing, move a couple of SELECT-INTO-specific fields out of EState and into the private state of the SELECT INTO DestReceiver, as was foreseen in an old comment there. Also make intorel_receive use ExecMaterializeSlot not ExecCopySlotTuple, for consistency with ExecInsert and to possibly save a tuple copy step in some cases.
* 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
* Provide a function hook to let plug-ins get control around ExecutorRun.Tom Lane2008-07-18
| | | | ITAGAKI Takahiro
* Fix mis-calculation of extParam/allParam sets for plan nodes, as seen inTom Lane2008-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | bug #4290. The fundamental bug is that masking extParam by outer_params, as finalize_plan had been doing, caused us to lose the information that an initPlan depended on the output of a sibling initPlan. On reflection the best thing to do seemed to be not to try to adjust outer_params for this case but get rid of it entirely. The only thing it was really doing for us was to filter out param IDs associated with SubPlan nodes, and that can be done (with greater accuracy) while processing individual SubPlan nodes in finalize_primnode. This approach was vindicated by the discovery that the masking method was hiding a second bug: SS_finalize_plan failed to remove extParam bits for initPlan output params that were referenced in the main plan tree (it only got rid of those referenced by other initPlans). It's not clear that this caused any real problems, given the limited use of extParam by the executor, but it's certainly not what was intended. I originally thought that there was also a problem with needing to include indirect dependencies on external params in initPlans' param sets, but it turns out that the executor handles this correctly so long as the depended-on initPlan is earlier in the initPlans list than the one using its output. That seems a bit of a fragile assumption, but it is true at the moment, so I just documented it in some code comments rather than making what would be rather invasive changes to remove the assumption. Back-patch to 8.1. Previous versions don't have the case of initPlans referring to other initPlans' outputs, so while the existing logic is still questionable for them, there are not any known bugs to be fixed. So I'll refrain from changing them for now.
* 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.
* Refactor SPI_cursor_open/SPI_cursor_open_with_args so that the latter setsTom Lane2008-06-01
| | | | | | | | the PARAM_FLAG_CONST flag on the parameters that are passed into the portal, while the former's behavior is unchanged. This should only affect the case where the portal is executing an EXPLAIN; it will cause the generated plan to look more like what would be generated if the portal were actually executing the command being explained. Per gripe from Pavel.
* 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)
* Move the "instr_time" typedef and associated macros into a new headerTom Lane2008-05-14
| | | | | | | | | file portability/instr_time.h, and add a couple more macros to eliminate some abstraction leakage we formerly had. Also update psql to use this header instead of its own copy of nearly the same code. This commit in itself is just code cleanup and shouldn't change anything. It lays some groundwork for the upcoming function-stats patch, though.
* This is the patch replace offnum++ by OffsetNumberNext, to beBruce Momjian2008-05-13
| | | | | | consistent. OffsetNumberNext() has some casting that makes it useful. Fujii Masao
* 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.
* Change the rules for inherited CHECK constraints to be essentially the sameTom Lane2008-05-09
| | | | | | | | | | | | | | | | as those for inherited columns; that is, it's no longer allowed for a child table to not have a check constraint matching one that exists on a parent. This satisfies the principle of least surprise (rows selected from the parent will always appear to meet its check constraints) and eliminates some longstanding bogosity in pg_dump, which formerly had to guess about whether check constraints were really inherited or not. The implementation involves adding conislocal and coninhcount columns to pg_constraint (paralleling attislocal and attinhcount in pg_attribute) and refactoring various ALTER TABLE actions to be more like those for columns. Alex Hunsaker, Nikhil Sontakke, Tom Lane
* Fix nodeTidscan.c to not trigger an error if the block number portion ofTom Lane2008-04-30
| | | | | | | | a user-supplied TID is out of range for the relation. This is needed to preserve compatibility with our pre-8.3 behavior, and it is sensible anyway since if the query were implemented by brute force rather than optimized into a TidScan, the behavior for a non-existent TID would be zero rows out, never an error. Per gripe from Gurjeet Singh.
* Fix a couple of places in execMain that erroneously assumed that SELECT FORTom Lane2008-04-21
| | | | | | | | | | UPDATE/SHARE couldn't occur as a subquery in a query with a non-SELECT top-level operation. Symptoms included outright failure (as in report from Mark Mielke) and silently neglecting to take the requested row locks. Back-patch to 8.3, because the visible failure in the INSERT ... SELECT case is a regression from 8.2. I'm a bit hesitant to back-patch further given the lack of field complaints.
* 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.
* Phase 2 of project to make index operator lossiness be determined at runtimeTom Lane2008-04-13
| | | | | | | | | | | | instead of plan time. Extend the amgettuple API so that the index AM returns a boolean indicating whether the indexquals need to be rechecked, and make that rechecking happen in nodeIndexscan.c (currently the only place where it's expected to be needed; other callers of index_getnext are just erroring out for now). For the moment, GIN and GIST have stub logic that just always sets the recheck flag to TRUE --- I'm hoping to get Teodor to handle pushing that control down to the opclass consistent() functions. The planner no longer pays any attention to amopreqcheck, and that catalog column will go away in due course.
* Replace "amgetmulti" AM functions with "amgetbitmap", in which the wholeTom Lane2008-04-10
| | | | | | | | | | | | | | | | | | indexscan always occurs in one call, and the results are returned in a TIDBitmap instead of a limited-size array of TIDs. This should improve speed a little by reducing AM entry/exit overhead, and it is necessary infrastructure if we are ever to support bitmap indexes. In an only slightly related change, add support for TIDBitmaps to preserve (somewhat lossily) the knowledge that particular TIDs reported by an index need to have their quals rechecked when the heap is visited. This facility is not really used yet; we'll need to extend the forced-recheck feature to plain indexscans before it's useful, and that hasn't been coded yet. The intent is to use it to clean up 8.3's horrid @@@ kluge for text search with weighted queries. There might be other uses in future, but that one alone is sufficient reason. Heikki Linnakangas, with some adjustments by me.
* Revert my bad decision of about a year ago to make PortalDefineQueryTom Lane2008-04-02
| | | | | | | | | | | | | | responsible for copying the query string into the new Portal. Such copying is unnecessary in the common code path through exec_simple_query, and in this case it can be enormously expensive because the string might contain a large number of individual commands; we were copying the entire, long string for each command, resulting in O(N^2) behavior for N commands. (This is the cause of bug #4079.) A second problem with it is that PortalDefineQuery really can't risk error, because if it elog's before having set up the Portal, we will leak the plancache refcount that the caller is trying to hand off to the portal. So go back to the design in which the caller is responsible for making sure everything is copied into the portal if necessary.
* Add SPI-level support for executing SQL commands with one-time-use plans,Tom Lane2008-04-01
| | | | | | | | | | | that is commands that have out-of-line parameters but the plan is prepared assuming that the parameter values are constants. This is needed for the plpgsql EXECUTE USING patch, but will probably have use elsewhere. This commit includes the SPI functions and documentation, but no callers nor regression tests. The upcoming EXECUTE USING patch will provide regression-test coverage. I thought committing this separately made sense since it's logically a distinct feature.
* Support statement-level ON TRUNCATE triggers. Simon RiggsTom Lane2008-03-28
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* Move the HTSU_Result enum definition into snapshot.h, to avoid includingAlvaro Herrera2008-03-26
| | | | | | tqual.h into heapam.h. This makes all inclusion of tqual.h explicit. I also sorted alphabetically the includes on some source files.
* Rename snapmgmt.c/h to snapmgr.c/h, for consistency with other files.Alvaro Herrera2008-03-26
| | | | Per complaint from Tom Lane.
* Separate snapshot management code from tuple visibility code, create aAlvaro Herrera2008-03-26
| | | | | | | | | | | | | snapmgmt.c file for the former. The header files have also been reorganized in three parts: the most basic snapshot definitions are now in a new file snapshot.h, and the also new snapmgmt.h keeps the definitions for snapmgmt.c. tqual.h has been reduced to the bare minimum. This patch is just a first step towards managing live snapshots within a transaction; there is no functionality change. Per my proposal to pgsql-patches on 20080318191940.GB27458@alvh.no-ip.org and subsequent discussion.
* Simplify and standardize conversions between TEXT datums and ordinary CTom Lane2008-03-25
| | | | | | | | | | | | | | | | | | | | strings. This patch introduces four support functions cstring_to_text, cstring_to_text_with_len, text_to_cstring, and text_to_cstring_buffer, and two macros CStringGetTextDatum and TextDatumGetCString. A number of existing macros that provided variants on these themes were removed. Most of the places that need to make such conversions now require just one function or macro call, in place of the multiple notational layers that used to be needed. There are no longer any direct calls of textout or textin, and we got most of the places that were using handmade conversions via memcpy (there may be a few still lurking, though). This commit doesn't make any serious effort to eliminate transient memory leaks caused by detoasting toasted text objects before they reach text_to_cstring. We changed PG_GETARG_TEXT_P to PG_GETARG_TEXT_PP in a few places where it was easy, but much more could be done. Brendan Jurd and Tom Lane
* Add a new tuplestore API function, tuplestore_putvalues(). This isNeil Conway2008-03-25
| | | | | | | identical to tuplestore_puttuple(), except it operates on arrays of Datums + nulls rather than a fully-formed HeapTuple. In several places that use the tuplestore API, this means we can avoid creating a HeapTuple altogether, saving a copy.
* Avoid a useless tuple copy within nodeMaterial. Neil ConwayTom Lane2008-03-23
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* More README src cleanups.Bruce Momjian2008-03-21
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* Add a couple of missing FreeQueryDesc calls. Noticed while testing aAlvaro Herrera2008-03-20
| | | | framework to keep track of snapshots in use.
* Make source code READMEs more consistent. Add CVS tags to all README files.Bruce Momjian2008-03-20
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* Arrange to "inline" SQL functions that appear in a query's FROM clause,Tom Lane2008-03-18
| | | | | | | are declared to return set, and consist of just a single SELECT. We can replace the FROM-item with a sub-SELECT and then optimize much as if we were dealing with a view. Patch from Richard Rowell, cleaned up by me.
* Advance multiple array keys rightmost-first instead of leftmost-firstTom Lane2008-03-18
| | | | | | during a bitmap index scan. This cannot affect the query results (since we're just dumping the TIDs into a bitmap) but it might offer some advantage in locality of access to the index. Per Greg Stark.
* Throw an error for negative LIMIT or OFFSET values, instead of silentlyTom Lane2008-03-10
| | | | treating them as zero. Simon Riggs
* Fix several memory leaks when rescanning SRFs. Arrange for an SRF'sNeil Conway2008-02-29
| | | | | | | | | | | | | | | | | | "multi_call_ctx" to be a distinct sub-context of the EState's per-query context, and delete the multi_call_ctx as soon as the SRF finishes execution. This avoids leaking SRF memory until the end of the current query, which is particularly egregious when the SRF is scanned multiple times. This change also fixes a leak of the fields of the AttInMetadata struct in shutdown_MultiFuncCall(). Also fix a leak of the SRF result TupleDesc when rescanning a FunctionScan node. The TupleDesc is allocated in the per-query context for every call to ExecMakeTableFunctionResult(), so we should free it after calling that function. Since the SRF might choose to return a non-expendable TupleDesc, we only free the TupleDesc if it is not being reference-counted. Backpatch to 8.3 and 8.2 stable branches.
* Refactor backend makefiles to remove lots of duplicate codePeter Eisentraut2008-02-19
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* Fix SPI_cursor_open() and SPI_is_cursor_plan() to push the SPI stack beforeTom Lane2008-02-12
| | | | | | | | | | | | | | | | | | | | | doing anything interesting, such as calling RevalidateCachedPlan(). The necessity of this is demonstrated by an example from Willem Buitendyk: during a replan, the planner might try to evaluate SPI-using functions, and so we'd better be in a clean SPI context. A small downside of this fix is that these two functions will now fail outright if called when not inside a SPI-using procedure (ie, a SPI_connect/SPI_finish pair). The documentation never promised or suggested that that would work, though; and they are normally used in concert with other functions, mainly SPI_prepare, that always have failed in such a case. So the odds of breaking something seem pretty low. In passing, make SPI_is_cursor_plan's error handling convention clearer, and fix documentation's erroneous claim that SPI_cursor_open would return NULL on error. Before 8.3 these functions could not invoke replanning, so there is probably no need for back-patching.
* Fix CREATE TABLE ... LIKE ... INCLUDING INDEXES to not cause unwantedTom Lane2008-02-07
| | | | | | | | | | | tablespace permissions failures when copying an index that is in the database's default tablespace. A side-effect of the change is that explicitly specifying the default tablespace no longer triggers a permissions check; this is not how it was done in pre-8.3 releases but is argued to be more consistent. Per bug #3921 from Andrew Gilligan. (Note: I argued in the subsequent discussion that maybe LIKE shouldn't copy index tablespaces at all, but since no one indicated agreement with that idea, I've refrained from doing it.)
* The original implementation of polymorphic aggregates didn't really get theTom Lane2008-01-11
| | | | | | checking of argument compatibility right; although the problem is only exposed with multiple-input aggregates in which some arguments are polymorphic and some are not. Per bug #3852 from Sokolov Yura.
* Update copyrights in source tree to 2008.Bruce Momjian2008-01-01
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* Avoid incrementing the CommandCounter when CommandCounterIncrement is calledTom Lane2007-11-30
| | | | | | | | | | | | | | | | | | | | but no database changes have been made since the last CommandCounterIncrement. This should result in a significant improvement in the number of "commands" that can typically be performed within a transaction before hitting the 2^32 CommandId size limit. In particular this buys back (and more) the possible adverse consequences of my previous patch to fix plan caching behavior. The implementation requires tracking whether the current CommandCounter value has been "used" to mark any tuples. CommandCounter values stored into snapshots are presumed not to be used for this purpose. This requires some small executor changes, since the executor used to conflate the curcid of the snapshot it was using with the command ID to mark output tuples with. Separating these concepts allows some small simplifications in executor APIs. Something for the TODO list: look into having CommandCounterIncrement not do AcceptInvalidationMessages. It seems fairly bogus to be doing it there, but exactly where to do it instead isn't clear, and I'm disinclined to mess with asynchronous behavior during late beta.
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