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path: root/src/backend/executor/nodeIndexscan.c
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2006-12-26Repair bug #2839: the various ExecReScan functions need to resetTom Lane
ps_TupFromTlist in plan nodes that make use of it. This was being done correctly in join nodes and Result nodes but not in any relation-scan nodes. Bug would lead to bogus results if a set-returning function appeared in the targetlist of a subquery that could be rescanned after partial execution, for example a subquery within EXISTS(). Bug has been around forever :-( ... surprising it wasn't reported before.
2006-10-04pgindent run for 8.2.Bruce Momjian
2006-07-31Change the relation_open protocol so that we obtain lock on a relationTom Lane
(table or index) before trying to open its relcache entry. This fixes race conditions in which someone else commits a change to the relation's catalog entries while we are in process of doing relcache load. Problems of that ilk have been reported sporadically for years, but it was not really practical to fix until recently --- for instance, the recent addition of WAL-log support for in-place updates helped. Along the way, remove pg_am.amconcurrent: all AMs are now expected to support concurrent update.
2006-07-14Remove 576 references of include files that were not needed.Bruce Momjian
2006-06-16Fix problems with cached tuple descriptors disappearing while still in useTom Lane
by creating a reference-count mechanism, similar to what we did a long time ago for catcache entries. The back branches have an ugly solution involving lots of extra copies, but this way is more efficient. Reference counting is only applied to tupdescs that are actually in caches --- there seems no need to use it for tupdescs that are generated in the executor, since they'll go away during plan shutdown by virtue of being in the per-query memory context. Neil Conway and Tom Lane
2006-05-23Remove CXT_printf/CXT1_printf macros. If anyone had found them to be ofTom Lane
any use in the past many years, we'd have made some effort to include them in all executor node types; but in fact they were only in nodeAppend.c and nodeIndexscan.c, up until I copied nodeIndexscan.c's occurrence into the new bitmap node types. Remove some other unused macros in execdebug.h, too. Some day the whole header probably ought to go away in favor of better-designed facilities.
2006-03-05Update copyright for 2006. Update scripts.Bruce Momjian
2006-02-28Extend the ExecInitNode API so that plan nodes receive a set of flagTom Lane
bits indicating which optional capabilities can actually be exercised at runtime. This will allow Sort and Material nodes, and perhaps later other nodes, to avoid unnecessary overhead in common cases. This commit just adds the infrastructure and arranges to pass the correct flag values down to plan nodes; none of the actual optimizations are here yet. I'm committing this separately in case anyone wants to measure the added overhead. (It should be negligible.) Simon Riggs and Tom Lane
2006-01-25Allow row comparisons to be used as indexscan qualifications.Tom Lane
This completes the project to upgrade our handling of row comparisons.
2005-12-03Tweak indexscan machinery to avoid taking an AccessShareLock on an indexTom Lane
if we already have a stronger lock due to the index's table being the update target table of the query. Same optimization I applied earlier at the table level. There doesn't seem to be much interest in the more radical idea of not locking indexes at all, so do what we can ...
2005-12-02Adjust scan plan nodes to avoid getting an extra AccessShareLock on aTom Lane
relation if it's already been locked by execMain.c as either a result relation or a FOR UPDATE/SHARE relation. This avoids an extra trip to the shared lock manager state. Per my suggestion yesterday.
2005-11-25Teach planner and executor to handle ScalarArrayOpExpr as an indexableTom Lane
qualification when the underlying operator is indexable and useOr is true. That is, indexkey op ANY (ARRAY[...]) is effectively translated into an OR combination of one indexscan for each array element. This only works for bitmap index scans, of course, since regular indexscans no longer support OR'ing of scans. There are still some loose ends to clean up before changing 'x IN (list)' to translate as a ScalarArrayOpExpr; for instance predtest.c ought to be taught about it. But this gets the basic functionality in place.
2005-11-25Improve ExecStoreTuple to be smarter about replacing the contents ofTom Lane
a TupleTableSlot: instead of calling ExecClearTuple, inline the needed operations, so that we can avoid redundant steps. In particular, when the old and new tuples are both on the same disk page, avoid releasing and re-acquiring the buffer pin --- this saves work in both the bufmgr and ResourceOwner modules. To make this improvement actually useful, partially revert a change I made on 2004-04-21 that caused SeqNext et al to call ExecClearTuple before ExecStoreTuple. The motivation for that, to avoid grabbing the BufMgrLock separately for releasing the old buffer and grabbing the new one, no longer applies. My profiling says that this saves about 5% of the CPU time for an all-in-memory seqscan.
2005-11-22Re-run pgindent, fixing a problem where comment lines after a blankBruce Momjian
comment line where output as too long, and update typedefs for /lib directory. Also fix case where identifiers were used as variable names in the backend, but as typedefs in ecpg (favor the backend for indenting). Backpatch to 8.1.X.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-05-06For some reason access/tupmacs.h has been #including utils/memutils.h,Tom Lane
which is neither needed by nor related to that header. Remove the bogus inclusion and instead include the header in those C files that actually need it. Also fix unnecessary inclusions and bad inclusion order in tsearch2 files.
2005-04-25Remove support for OR'd indexscans internal to a single IndexScan planTom Lane
node, as this behavior is now better done as a bitmap OR indexscan. This allows considerable simplification in nodeIndexscan.c itself as well as several planner modules concerned with indexscan plan generation. Also we can improve the sharing of code between regular and bitmap indexscans, since they are now working with nigh-identical Plan nodes.
2005-04-23Remove explicit FreeExprContext calls during plan node shutdown. TheTom Lane
ExprContexts will be freed anyway when FreeExecutorState() is reached, and letting that routine do the work is more efficient because it will automatically free the ExprContexts in reverse creation order. The existing coding was effectively freeing them in exactly the worst possible order, resulting in O(N^2) behavior inside list_delete_ptr, which becomes highly visible in cases with a few thousand plan nodes. ExecFreeExprContext is now effectively a no-op and could be removed, but I left it in place in case we ever want to put it back to use.
2005-03-16Revise TupleTableSlot code to avoid unnecessary construction and disassemblyTom Lane
of tuples when passing data up through multiple plan nodes. A slot can now hold either a normal "physical" HeapTuple, or a "virtual" tuple consisting of Datum/isnull arrays. Upper plan levels can usually just copy the Datum arrays, avoiding heap_formtuple() and possible subsequent nocachegetattr() calls to extract the data again. This work extends Atsushi Ogawa's earlier patch, which provided the key idea of adding Datum arrays to TupleTableSlots. (I believe however that something like this was foreseen way back in Berkeley days --- see the old comment on ExecProject.) A test case involving many levels of join of fairly wide tables (about 80 columns altogether) showed about 3x overall speedup, though simple queries will probably not be helped very much. I have also duplicated some code in heaptuple.c in order to provide versions of heap_formtuple and friends that use "bool" arrays to indicate null attributes, instead of the old convention of "char" arrays containing either 'n' or ' '. This provides a better match to the convention used by ExecEvalExpr. While I have not made a concerted effort to get rid of uses of the old routines, I think they should be deprecated and eventually removed.
2004-12-31Tag appropriate files for rc3PostgreSQL Daemon
Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
2004-10-25Modify hash_create() to elog(ERROR) if an error occurs, rather thanNeil Conway
returning a NULL pointer (some callers remembered to check the return value, but some did not -- it is safer to just bail out). Also, cleanup pgstat.c to use elog(ERROR) rather than elog(LOG) followed by exit().
2004-08-29Pgindent run for 8.0.Bruce Momjian
2004-08-29Update copyright to 2004.Bruce Momjian
2004-05-30Use the new List API function names throughout the backend, and disable theNeil Conway
list compatibility API by default. While doing this, I decided to keep the llast() macro around and introduce llast_int() and llast_oid() variants.
2004-05-26Reimplement the linked list data structure used throughout the backend.Neil Conway
In the past, we used a 'Lispy' linked list implementation: a "list" was merely a pointer to the head node of the list. The problem with that design is that it makes lappend() and length() linear time. This patch fixes that problem (and others) by maintaining a count of the list length and a pointer to the tail node along with each head node pointer. A "list" is now a pointer to a structure containing some meta-data about the list; the head and tail pointers in that structure refer to ListCell structures that maintain the actual linked list of nodes. The function names of the list API have also been changed to, I hope, be more logically consistent. By default, the old function names are still available; they will be disabled-by-default once the rest of the tree has been updated to use the new API names.
2004-04-21Tweak indexscan and seqscan code to arrange that steps from one page toTom Lane
the next are handled by ReleaseAndReadBuffer rather than separate ReleaseBuffer and ReadBuffer calls. This cuts the number of acquisitions of the BufMgrLock by a factor of 2 (possibly more, if an indexscan happens to pull successive rows from the same heap page). Unfortunately this doesn't seem enough to get us out of the recently discussed context-switch storm problem, but it's surely worth doing anyway.
2004-02-28Remove unneeded indxqual field in IndexScanState, and the useless workTom Lane
spent initializing it during indexscan startup.
2004-02-03Rename SortMem and VacuumMem to work_mem and maintenance_work_mem.Tom Lane
Make btree index creation and initial validation of foreign-key constraints use maintenance_work_mem rather than work_mem as their memory limit. Add some code to guc.c to allow these variables to be referenced by their old names in SHOW and SET commands, for backwards compatibility.
2004-01-07More janitorial work: remove the explicit casting of NULL literals to aNeil Conway
pointer type when it is not necessary to do so. For future reference, casting NULL to a pointer type is only necessary when (a) invoking a function AND either (b) the function has no prototype OR (c) the function is a varargs function.
2004-01-06Instead of rechecking lossy index operators by putting them into theTom Lane
regular qpqual ('filter condition'), add special-purpose code to nodeIndexscan.c to recheck them. This ends being almost no net addition of code, because the removal of planner code balances out the extra executor code, but it is significantly more efficient when a lossy operator is involved in an OR indexscan. The old implementation had to recheck the entire indexqual in such cases.
2003-12-30Avoid running out of memory during hash_create, by not passing aTom Lane
number-of-buckets that exceeds the size we actually plan to allow the hash table to grow to. Per trouble report from Sean Shanny.
2003-11-29$Header: -> $PostgreSQL Changes ...PostgreSQL Daemon
2003-11-12Cross-data-type comparisons are now indexable by btrees, pursuant to myTom Lane
pghackers proposal of 8-Nov. All the existing cross-type comparison operators (int2/int4/int8 and float4/float8) have appropriate support. The original proposal of storing the right-hand-side datatype as part of the primary key for pg_amop and pg_amproc got modified a bit in the event; it is easier to store zero as the 'default' case and only store a nonzero when the operator is actually cross-type. Along the way, remove the long-since-defunct bigbox_ops operator class.
2003-11-09Add operator strategy and comparison-value datatype fields to ScanKey.Tom Lane
Remove the 'strategy map' code, which was a large amount of mechanism that no longer had any use except reverse-mapping from procedure OID to strategy number. Passing the strategy number to the index AM in the first place is simpler and faster. This is a preliminary step in planned support for cross-datatype index operations. I'm committing it now since the ScanKeyEntryInitialize() API change touches quite a lot of files, and I want to commit those changes before the tree drifts under me.
2003-09-24Repair some REINDEX problems per recent discussions. The relcache isTom Lane
now able to cope with assigning new relfilenode values to nailed-in-cache indexes, so they can be reindexed using the fully crash-safe method. This leaves only shared system indexes as special cases. Remove the 'index deactivation' code, since it provides no useful protection in the shared- index case. Require reindexing of shared indexes to be done in standalone mode, but remove other restrictions on REINDEX. -P (IgnoreSystemIndexes) now prevents using indexes for lookups, but does not disable index updates. It is therefore safe to allow from PGOPTIONS. Upshot: reindexing system catalogs can be done without a standalone backend for all cases except shared catalogs.
2003-08-22Tweak processing of multiple-index-scan plans to reduce overhead whenTom Lane
handling many-way scans: instead of re-evaluating all prior indexscan quals to see if a tuple has been fetched more than once, use a hash table indexed by tuple CTID. But fall back to the old way if the hash table grows to exceed SortMem.
2003-08-04Update copyrights to 2003.Bruce Momjian
2003-08-04pgindent run.Bruce Momjian
2003-07-21Error message editing in backend/executor.Tom Lane
2003-02-09Create a distinction between Lists of integers and Lists of OIDs, to getTom Lane
rid of the assumption that sizeof(Oid)==sizeof(int). This is one small step towards someday supporting 8-byte OIDs. For the moment, it doesn't do much except get rid of a lot of unsightly casts.
2003-02-03Tweak planner and executor to avoid doing ExecProject() in table scanTom Lane
nodes where it's not really necessary. In many cases where the scan node is not the topmost plan node (eg, joins, aggregation), it's possible to just return the table tuple directly instead of generating an intermediate projection tuple. In preliminary testing, this reduced the CPU time needed for 'SELECT COUNT(*) FROM foo' by about 10%.
2003-01-12Fix wrong/misleading comments, be more consistent about where to callTom Lane
ExecAssignResultTypeFromTL().
2002-12-18Prevent core dump when ExecMarkPos is called before any tuples have beenTom Lane
retrieved. This cannot happen in ordinary execution, but it can happen under EvalPlanQual().
2002-12-15Revise executor APIs so that all per-query state structure is built inTom Lane
a per-query memory context created by CreateExecutorState --- and destroyed by FreeExecutorState. This provides a final solution to the longstanding problem of memory leaked by various ExecEndNode calls.
2002-12-13Phase 3 of read-only-plans project: ExecInitExpr now builds expressionTom Lane
execution state trees, and ExecEvalExpr takes an expression state tree not an expression plan tree. The plan tree is now read-only as far as the executor is concerned. Next step is to begin actually exploiting this property.
2002-12-12Phase 2 of read-only-plans project: restructure expression-tree nodesTom Lane
so that all executable expression nodes inherit from a common supertype Expr. This is somewhat of an exercise in code purity rather than any real functional advance, but getting rid of the extra Oper or Func node formerly used in each operator or function call should provide at least a little space and speed improvement. initdb forced by changes in stored-rules representation.
2002-12-05Phase 1 of read-only-plans project: cause executor state nodes to pointTom Lane
to plan nodes, not vice-versa. All executor state nodes now inherit from struct PlanState. Copying of plan trees has been simplified by not storing a list of SubPlans in Plan nodes (eliminating duplicate links). The executor still needs such a list, but it can build it during ExecutorStart since it has to scan the plan tree anyway. No initdb forced since no stored-on-disk structures changed, but you will need a full recompile because of node-numbering changes.
2002-09-04pgindent run.Bruce Momjian
2002-06-23It seems that ExecInit/EndIndexScan is leaking some memory...Bruce Momjian
For example, if I run a query, that uses an index scan, and call MemoryContextSt ats (CurrentMemoryContext) before ExecutorStart() and after ExecutorEnd() in ProcessQuery(), I am consistently see ing that the 'after' call shows 256 bytes more used, then 'before'... The problem seems to be in ExecEndIndexScan - it does not release scanstate, ind exstate, indexstate->iss_RelationDescs and indexstate -> iss_ScanDescs... Dmitry Tkach
2002-06-20Update copyright to 2002.Bruce Momjian