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path: root/src/backend/optimizer/path/orindxpath.c
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* Re-run pgindent, fixing a problem where comment lines after a blankBruce Momjian2005-11-22
| | | | | | | | | 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.
* Restore the former RestrictInfo field valid_everywhere (but invert the flagTom Lane2005-11-14
| | | | | | | | | | sense and rename to "outerjoin_delayed" to more clearly reflect what it means). I had decided that it was redundant in 8.1, but the folly of this is exposed by a bug report from Sebastian Böck. The place where it's needed is to prevent orindxpath.c from cherry-picking arms of an outer-join OR clause to form a relation restriction that isn't actually legal to push down to the relation scan level. There may be some legal cases that this forbids optimizing, but we'd need much closer analysis to determine it.
* Standard pgindent run for 8.1.Bruce Momjian2005-10-15
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* Fix a bunch of bad interactions between partial indexes and the newTom Lane2005-07-28
| | | | | | | | planning logic for bitmap indexscans. Partial indexes create corner cases in which a scan might be done with no explicit index qual conditions, and the code wasn't handling those cases nicely. Also be a little tenser about eliminating redundant clauses in the generated plan. Per report from Dmitry Karasik.
* Teach planner about some cases where a restriction clause can beTom Lane2005-07-02
| | | | | | | | | | | | | | | propagated inside an outer join. In particular, given LEFT JOIN ON (A = B) WHERE A = constant, we cannot conclude that B = constant at the top level (B might be null instead), but we can nonetheless put a restriction B = constant into the quals for B's relation, since no inner-side rows not meeting that condition can contribute to the final result. Similarly, given FULL JOIN USING (J) WHERE J = constant, we can't directly conclude that either input J variable = constant, but it's OK to push such quals into each input rel. Per recent gripe from Kim Bisgaard. Along the way, remove 'valid_everywhere' flag from RestrictInfo, as on closer analysis it was not being used for anything, and was defined backwards anyway.
* Simplify the planner's join clause management by storing join clausesTom Lane2005-06-09
| | | | | | | | | | of a relation in a flat 'joininfo' list. The former arrangement grouped the join clauses according to the set of unjoined relids used in each; however, profiling on test cases involving lots of joins proves that that data structure is a net loss. It takes more time to group the join clauses together than is saved by avoiding duplicate tests later. It doesn't help any that there are usually not more than one or two clauses per group ...
* Remove planner's private fields from Query struct, and put them intoTom Lane2005-06-05
| | | | | | | | a new PlannerInfo struct, which is passed around instead of the bare Query in all the planning code. This commit is essentially just a code-beautification exercise, but it does open the door to making larger changes to the planner data structures without having to muck with the widely-known Query struct.
* Replace slightly klugy create_bitmap_restriction() function with aTom Lane2005-04-25
| | | | | more efficient routine in restrictinfo.c (which can make use of make_restrictinfo_internal).
* Remove support for OR'd indexscans internal to a single IndexScan planTom Lane2005-04-25
| | | | | | | | 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.
* Install some slightly realistic cost estimation for bitmap index scans.Tom Lane2005-04-21
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* Add a back-link from IndexOptInfo structs to their parent RelOptInfoTom Lane2005-03-27
| | | | | | structs. There are many places in the planner where we were passing both a rel and an index to subroutines, and now need only pass the index struct. Notationally simpler, and perhaps a tad faster.
* Expand the 'special index operator' machinery to handle special casesTom Lane2005-03-26
| | | | | | | | | | | | for boolean indexes. Previously we would only use such an index with WHERE clauses like 'indexkey = true' or 'indexkey = false'. The new code transforms the cases 'indexkey', 'NOT indexkey', 'indexkey IS TRUE', and 'indexkey IS FALSE' into one of these. While this is only marginally useful in itself, I intend soon to change constant-expression simplification so that 'foo = true' and 'foo = false' are reduced to just 'foo' and 'NOT foo' ... which would lose the ability to use boolean indexes for such queries at all, if the indexscan machinery couldn't make the reverse transformation.
* Adjust OR indexscan logic to not generate redundant condition-free ORTom Lane2005-03-01
| | | | | | indexscans involving partial indexes. These would always be dominated by a simple indexscan on such an index, so there's no point in considering them. Fixes overoptimism in a patch I applied last October.
* Tag appropriate files for rc3PostgreSQL Daemon2004-12-31
| | | | | | | | 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 ...
* Fix OR-index-scan planner to recognize that a partial index is usableTom Lane2004-10-11
| | | | | | | | | | | | | | | | | | | | | for scanning one term of an OR clause if the index's predicate is implied by that same OR clause term (possibly in conjunction with top-level WHERE clauses). Per recent example from Dawid Kuroczko, http://archives.postgresql.org/pgsql-performance/2004-10/msg00095.php Also, fix a very long-standing bug in index predicate testing, namely the bizarre ordering of decomposition of predicate and restriction clauses. AFAICS the correct way is to break down the predicate all the way, and then for each component term see if you can prove it from the entire restriction set. The original coding had a purely-implementation-artifact distinction between ANDing at the top level and ANDing below that, and proceeded to get the decomposition order wrong everywhere below the top level, with the result that even slightly complicated AND/OR predicates could not be proven. For instance, given create index foop on foo(f2) where f1=42 or f1=1 or (f1 = 11 and f2 = 55); the old code would fail to match this index to the query select * from foo where f1 = 11 and f2 = 55; when it obviously ought to match.
* Pgindent run for 8.0.Bruce Momjian2004-08-29
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* Update copyright to 2004.Bruce Momjian2004-08-29
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* Just about there on de-FastList-ification.Tom Lane2004-06-01
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* Use the new List API function names throughout the backend, and disable theNeil Conway2004-05-30
| | | | | list compatibility API by default. While doing this, I decided to keep the llast() macro around and introduce llast_int() and llast_oid() variants.
* Reimplement the linked list data structure used throughout the backend.Neil Conway2004-05-26
| | | | | | | | | | | | | | | | 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.
* Adjust indexscan planning logic to keep RestrictInfo nodes associatedTom Lane2004-01-05
| | | | | | | | | | | with index qual clauses in the Path representation. This saves a little work during createplan and (probably more importantly) allows reuse of cached selectivity estimates during indexscan planning. Also fix latent bug: wrong plan would have been generated for a 'special operator' used in a nestloop-inner-indexscan join qual, because the special operator would not have gotten into the list of quals to recheck. This bug is only latent because at present the special-operator code could never trigger on a join qual, but sooner or later someone will want to do it.
* Add the ability to extract OR indexscan conditions from OR-of-ANDTom Lane2004-01-05
| | | | | | | join conditions in which each OR subclause includes a constraint on the same relation. This implements the other useful side-effect of conversion to CNF format, without its unpleasant side-effects. As per pghackers discussion of a few weeks ago.
* Rewrite OR indexscan processing to be more flexible. We can now for theTom Lane2004-01-04
| | | | | | | | | first time generate an OR indexscan for a two-column index when the WHERE condition is like 'col1 = foo AND (col2 = bar OR col2 = baz)' --- before, the OR had to be on the first column of the index or we'd not notice the possibility of using it. Some progress towards extracting OR indexscans from subclauses of an OR that references multiple relations, too, although this code is #ifdef'd out because it needs more work.
* $Header: -> $PostgreSQL Changes ...PostgreSQL Daemon2003-11-29
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* Update copyrights to 2003.Bruce Momjian2003-08-04
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* pgindent run.Bruce Momjian2003-08-04
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* Adjust nestloop-with-inner-indexscan plan generation so that we catchTom Lane2003-06-15
| | | | | | | some cases of redundant clauses that were formerly not caught. We have to special-case this because the clauses involved never get attached to the same join restrictlist and so the existing logic does not notice that they are redundant.
* Fix some planner performance problems with large WHERE clauses, byTom Lane2003-05-28
| | | | | | | introducing new 'FastList' list-construction subroutines to use in hot spots. This avoids the O(N^2) behavior of repeated lappend's by keeping a tail pointer, while not changing behavior by reversing list order as the lcons() method would do.
* Phase 2 of read-only-plans project: restructure expression-tree nodesTom Lane2002-12-12
| | | | | | | | | 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.
* Restructure planning of nestloop inner indexscans so that the set of usableTom Lane2002-11-24
| | | | | | | | | | | joinclauses is determined accurately for each join. Formerly, the code only considered joinclauses that used all of the rels from the outer side of the join; thus for example FROM (a CROSS JOIN b) JOIN c ON (c.f1 = a.x AND c.f2 = b.y) could not exploit a two-column index on c(f1,f2), since neither of the qual clauses would be in the joininfo list it looked in. The new code does this correctly, and also is able to eliminate redundant clauses, thus fixing the problem noted 24-Oct-02 by Hans-Jürgen Schönig.
* Update copyright to 2002.Bruce Momjian2002-06-20
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* Another pgindent run. Fixes enum indenting, and improves #endifBruce Momjian2001-10-28
| | | | spacing. Also adds space for one-line comments.
* pgindent run on all C files. Java run to follow. initdb/regressionBruce Momjian2001-10-25
| | | | tests pass.
* Improve planning of OR indexscan plans: for quals likeTom Lane2001-06-05
| | | | | | | | WHERE (a = 1 or a = 2) and b = 42 and an index on (a,b), include the clause b = 42 in the indexquals generated for each arm of the OR clause. Essentially this is an index- driven conversion from CNF to DNF. Implementation is a bit klugy, but better than not exploiting the extra quals at all ...
* Modify optimizer data structures so that IndexOptInfo lists built forTom Lane2001-05-20
| | | | | | | | create_index_paths are not immediately discarded, but are available for subsequent planner work. This allows avoiding redundant syscache lookups in several places. Change interface to operator selectivity estimation procedures to allow faster and more flexible estimation. Initdb forced due to change of pg_proc entries for selectivity functions!
* Change Copyright from PostgreSQL, Inc to PostgreSQL Global Development Group.Bruce Momjian2001-01-24
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* First cut at full support for OUTER JOINs. There are still a few looseTom Lane2000-09-12
| | | | | ends to clean up (see my message of same date to pghackers), but mostly it works. INITDB REQUIRED!
* Remove unused include files. Do not touch /port or includes used by defines.Bruce Momjian2000-05-30
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* Ye-old pgindent run. Same 4-space tabs.Bruce Momjian2000-04-12
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* Repair logic flaw in cost estimator: cost_nestloop() was estimating CPUTom Lane2000-03-22
| | | | | | | | | | | | | costs using the inner path's parent->rows count as the number of tuples processed per inner scan iteration. This is wrong when we are using an inner indexscan with indexquals based on join clauses, because the rows count in a Relation node reflects the selectivity of the restriction clauses for that rel only. Upshot was that if join clause was very selective, we'd drastically overestimate the true cost of the join. Fix is to calculate correct output-rows estimate for an inner indexscan when the IndexPath node is created and save it in the path node. Change of path node doesn't require initdb, since path nodes don't appear in saved rules.
* New cost model for planning, incorporating a penalty for random pageTom Lane2000-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | accesses versus sequential accesses, a (very crude) estimate of the effects of caching on random page accesses, and cost to evaluate WHERE- clause expressions. Export critical parameters for this model as SET variables. Also, create SET variables for the planner's enable flags (enable_seqscan, enable_indexscan, etc) so that these can be controlled more conveniently than via PGOPTIONS. Planner now estimates both startup cost (cost before retrieving first tuple) and total cost of each path, so it can optimize queries with LIMIT on a reasonable basis by interpolating between these costs. Same facility is a win for EXISTS(...) subqueries and some other cases. Redesign pathkey representation to achieve a major speedup in planning (I saw as much as 5X on a 10-way join); also minor changes in planner to reduce memory consumption by recycling discarded Path nodes and not constructing unnecessary lists. Minor cleanups to display more-plausible costs in some cases in EXPLAIN output. Initdb forced by change in interface to index cost estimation functions.
* Further cleanup for OR-of-AND WHERE-clauses. orindxpath can now handleTom Lane2000-02-05
| | | | | | extracting from an AND subclause just those opclauses that are relevant for a particular index. For example, we can now consider using an index on x to process WHERE (x = 1 AND y = 2) OR (x = 2 AND y = 4) OR ...
* Add:Bruce Momjian2000-01-26
| | | | | | * Portions Copyright (c) 1996-2000, PostgreSQL, Inc to all files copyright Regents of Berkeley. Man, that's a lot of files.
* Revise handling of index-type-specific indexscan cost estimation, perTom Lane2000-01-22
| | | | | | pghackers discussion of 5-Jan-2000. The amopselect and amopnpages estimators are gone, and in their place is a per-AM amcostestimate procedure (linked to from pg_am, not pg_amop).
* Another round of planner/optimizer work. This is just restructuring andTom Lane2000-01-09
| | | | | code cleanup; no major improvements yet. However, EXPLAIN does produce more intuitive outputs for nested loops with indexscans now...
* Major planner/optimizer revision: get rid of PathOrder node type,Tom Lane1999-08-16
| | | | | | | | | store all ordering information in pathkeys lists (which are now lists of lists of PathKeyItem nodes, not just lists of lists of vars). This was a big win --- the code is smaller and IMHO more understandable than it was, even though it handles more cases. I believe the node changes will not force an initdb for anyone; planner nodes don't show up in stored rules.
* First cut at doing LIKE/regex indexing optimization inTom Lane1999-07-27
| | | | | | | | | | | | | | | | | | optimizer rather than parser. This has many advantages, such as not getting fooled by chance uses of operator names ~ and ~~ (the operators are identified by OID now), and not creating useless comparison operations in contexts where the comparisons will not actually be used as indexquals. The new code also recognizes exact-match LIKE and regex patterns, and produces an = indexqual instead of >= and <=. This change does NOT fix the problem with non-ASCII locales: the code still doesn't know how to generate an upper bound indexqual for non-ASCII collation order. But it's no worse than before, just the same deficiency in a different place... Also, dike out loc_restrictinfo fields in Plan nodes. These were doing nothing useful in the absence of 'expensive functions' optimization, and they took a considerable amount of processing to fill in.
* Further work on planning of indexscans. Cleaned up interfacesTom Lane1999-07-25
| | | | | to index_selectivity so that it can be handed an indexqual clause list rather than a bunch of assorted derivative data.
* Clean up messy clause-selectivity code in clausesel.c; repair bugTom Lane1999-07-24
| | | | | | | | | | | | | | | | | | | | identified by Hiroshi (incorrect cost attributed to OR clauses after multiple passes through set_rest_selec()). I think the code was trying to allow selectivities of OR subclauses to be passed in from outside, but noplace was actually passing any useful data, and set_rest_selec() was passing wrong data. Restructure representation of "indexqual" in IndexPath nodes so that it is the same as for indxqual in completed IndexScan nodes: namely, a toplevel list with an entry for each pass of the index scan, having sublists that are implicitly-ANDed index qual conditions for that pass. You don't want to know what the old representation was :-( Improve documentation of OR-clause indexscan functions. Remove useless 'notclause' field from RestrictInfo nodes. (This might force an initdb for anyone who has stored rules containing RestrictInfos, but I do not think that RestrictInfo ever appears in completed plans.)
* Final cleanup.Bruce Momjian1999-07-16
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