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path: root/src/backend/optimizer/util/pathnode.c
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* 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.
* First cut at planner support for bitmap index scans. Lots to do yet,Tom Lane2005-04-22
| | | | | | | | but the code is basically working. Along the way, rewrite the entire approach to processing OR index conditions, and make it work in join cases for the first time ever. orindxpath.c is now basically obsolete, but I left it in for the time being to allow easy comparison testing against the old implementation.
* Rethink original decision to use AND/OR Expr nodes to represent bitmapTom Lane2005-04-21
| | | | | | | logic operations during planning. Seems cleaner to create two new Path node types, instead --- this avoids duplication of cost-estimation code. Also, create an enable_bitmapscan GUC parameter to control use of bitmap plans.
* Install some slightly realistic cost estimation for bitmap index scans.Tom Lane2005-04-21
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* Create executor and planner-backend support for decoupled heap and indexTom Lane2005-04-19
| | | | | | | | | scans, using in-memory tuple ID bitmaps as the intermediary. The planner frontend (path creation and cost estimation) is not there yet, so none of this code can be executed. I have tested it using some hacked planner code that is far too ugly to see the light of day, however. Committing now so that the bulk of the infrastructure changes go in before the tree drifts under me.
* Merge Resdom nodes into TargetEntry nodes to simplify code and save aTom Lane2005-04-06
| | | | | | | | | few palloc's. I also chose to eliminate the restype and restypmod fields entirely, since they are redundant with information stored in the node's contained expression; re-examining the expression at need seems simpler and more reliable than trying to keep restype/restypmod up to date. initdb forced due to change in contents of stored rules.
* 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.
* Make the behavior of HAVING without GROUP BY conform to the SQL spec.Tom Lane2005-03-10
| | | | | | | | | Formerly, if such a clause contained no aggregate functions we mistakenly treated it as equivalent to WHERE. Per spec it must cause the query to be treated as a grouped query of a single group, the same as appearance of aggregate functions would do. Also, the HAVING filter must execute after aggregate function computation even if it itself contains no aggregate functions.
* 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 ...
* 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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* Label CVS tip as 8.0devel instead of 7.5devel. Adjust various commentsTom Lane2004-08-04
| | | | and documentation to reference 8.0 instead of 7.5.
* Desultory de-FastList-ification. RelOptInfo.reltargetlist is back toTom Lane2004-06-01
| | | | being a plain List.
* 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.
* Remove the last traces of Joe Hellerstein's "xfunc" optimization. PatchNeil Conway2004-04-25
| | | | | from Alvaro Herrera. Also, removed lispsort.c, since it is no longer used.
* Use fuzzy comparison of path costs in add_path(), so that paths with theTom Lane2004-03-29
| | | | | | same path keys and nearly equivalent costs will be considered redundant. The exact nature of the fuzziness may get adjusted later based on current discussions, but no one has shot a hole in the basic idea yet ...
* Teach is_distinct_query to recognize that GROUP BY forces a subquery'sTom Lane2004-03-02
| | | | | output to be distinct, if all the GROUP BY columns appear in the output. Per suggestion from Dennis Haney.
* Rename SortMem and VacuumMem to work_mem and maintenance_work_mem.Tom Lane2004-02-03
| | | | | | | 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.
* Recognize that IN subqueries return already-unique results if they useTom Lane2004-01-19
| | | | | UNION/INTERSECT/EXCEPT (without ALL). This adds on to the previous optimization for subqueries using DISTINCT.
* 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.
* Improve UniquePath logic to detect the case where the input is alreadyTom Lane2004-01-05
| | | | | known unique (eg, it is a SELECT DISTINCT ... subquery), and not do a redundant unique-ification step.
* 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.
* $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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* Error message editing in backend/optimizer, backend/rewrite.Tom Lane2003-07-25
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* Make cost estimates for SubqueryScan more realistic: charge cpu_tuple_costTom Lane2003-07-14
| | | | | for each row processed, and don't forget the evaluation cost of any restriction clauses attached to the node. Per discussion with Greg Stark.
* Restructure building of join relation targetlists so that a join planTom Lane2003-06-29
| | | | | | | | | | | | | | node emits only those vars that are actually needed above it in the plan tree. (There were comments in the code suggesting that this was done at some point in the dim past, but for a long time we have just made join nodes emit everything that either input emitted.) Aside from being marginally more efficient, this fixes the problem noted by Peter Eisentraut where a join above an IN-implemented-as-join might fail, because the subplan targetlist constructed in the latter case didn't meet the expectation of including everything. Along the way, fix some places that were O(N^2) in the targetlist length. This is not all the trouble spots for wide queries by any means, but it's a step forward.
* 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.
* Cause CHAR(n) to TEXT or VARCHAR conversion to automatically strip trailingTom Lane2003-05-26
| | | | | | | | | | | | | | | | | | blanks, in hopes of reducing the surprise factor for newbies. Remove redundant operators for VARCHAR (it depends wholly on TEXT operations now). Clean up resolution of ambiguous operators/functions to avoid surprising choices for domains: domains are treated as equivalent to their base types and binary-coercibility is no longer considered a preference item when choosing among multiple operators/functions. IsBinaryCoercible now correctly reflects the notion that you need *only* relabel the type to get from type A to type B: that is, a domain is binary-coercible to its base type, but not vice versa. Various marginal cleanup, including merging the essentially duplicate resolution code in parse_func.c and parse_oper.c. Improve opr_sanity regression test to understand about binary compatibility (using pg_cast), and fix a couple of small errors in the catalogs revealed thereby. Restructure "special operator" handling to fetch operators via index opclasses rather than hardwiring assumptions about names (cleans up the pattern_ops stuff a little).
* Teach planner how to propagate pathkeys from sub-SELECTs in FROM up toTom Lane2003-02-15
| | | | | | | | | the outer query. (The implementation is a bit klugy, but it would take nontrivial restructuring to make it nicer, which this is probably not worth.) This avoids unnecessary sort steps in examples like SELECT foo,count(*) FROM (SELECT ... ORDER BY foo,bar) sub GROUP BY foo which means there is now a reasonable technique for controlling the order of inputs to custom aggregates, even in the grouping case.
* Replace planner's representation of relation sets, per pghackers discussion.Tom Lane2003-02-08
| | | | | Instead of Lists of integers, we now store variable-length bitmap sets. This should be faster as well as less error-prone.
* Upgrade cost estimation for joins, per discussion with Bradley Baetz.Tom Lane2003-01-27
| | | | | | | Try to model the effect of rescanning input tuples in mergejoins; account for JOIN_IN short-circuiting where appropriate. Also, recognize that mergejoin and hashjoin clauses may now be more than single operator calls, so we have to charge appropriate execution costs.
* Implement choice between hash-based and sort-based grouping for doingTom Lane2003-01-22
| | | | DISTINCT processing on the output of an IN sub-select.
* IN clauses appearing at top level of WHERE can now be handled as joins.Tom Lane2003-01-20
| | | | | | | | | | There are two implementation techniques: the executor understands a new JOIN_IN jointype, which emits at most one matching row per left-hand row, or the result of the IN's sub-select can be fed through a DISTINCT filter and then joined as an ordinary relation. Along the way, some minor code cleanup in the optimizer; notably, break out most of the jointree-rearrangement preprocessing in planner.c and put it in a new file prep/prepjointree.c.
* Phase 1 of read-only-plans project: cause executor state nodes to pointTom Lane2002-12-05
| | | | | | | | | | 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.
* Be more realistic about plans involving Materialize nodes: take theirTom Lane2002-11-30
| | | | cost into account while planning.
* Upgrade planner and executor to allow multiple hash keys for a hash join,Tom Lane2002-11-30
| | | | | | instead of only one. This should speed up planning (only one hash path to consider for a given pair of relations) as well as allow more effective hashing, when there are multiple hashable joinclauses.
* 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.
* First phase of implementing hash-based grouping/aggregation. An AGG planTom Lane2002-11-06
| | | | | | | | | | | | | node now does its own grouping of the input rows, and has no need for a preceding GROUP node in the plan pipeline. This allows elimination of the misnamed tuplePerGroup option for GROUP, and actually saves more code in nodeGroup.c than it costs in nodeAgg.c, as well as being presumably faster. Restructure the API of query_planner so that we do not commit to using a sorted or unsorted plan in query_planner; instead grouping_planner makes the decision. (Right now it isn't any smarter than query_planner was, but that will change as soon as it has the option to select a hash- based aggregation step.) Despite all the hackery, no initdb needed since only in-memory node types changed.
* Update copyright to 2002.Bruce Momjian2002-06-20
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* First pass at set-returning-functions in FROM, by Joe Conway withTom Lane2002-05-12
| | | | | | some kibitzing from Tom Lane. Not everything works yet, and there's no documentation or regression test, but let's commit this so Joe doesn't need to cope with tracking changes in so many files ...
* pgindent run on all C files. Java run to follow. initdb/regressionBruce Momjian2001-10-25
| | | | tests pass.
* Partial indexes work again, courtesy of Martijn van Oosterhout.Tom Lane2001-07-16
| | | | | | Note: I didn't force an initdb, figuring that one today was enough. However, there is a new function in pg_proc.h, and pg_dump won't be able to dump partial indexes until you add that function.
* Further work on making use of new statistics in planner. Adjust APIsTom Lane2001-06-05
| | | | | | | | | of costsize.c routines to pass Query root, so that costsize can figure more things out by itself and not be so dependent on its callers to tell it everything it needs to know. Use selectivity of hash or merge clause to estimate number of tuples processed internally in these joins (this is more useful than it would've been before, since eqjoinsel is somewhat more accurate than before).
* 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!
* Rewrite of planner statistics-gathering code. ANALYZE is now available asTom Lane2001-05-07
| | | | | | | | | | | | | | | | | a separate statement (though it can still be invoked as part of VACUUM, too). pg_statistic redesigned to be more flexible about what statistics are stored. ANALYZE now collects a list of several of the most common values, not just one, plus a histogram (not just the min and max values). Random sampling is used to make the process reasonably fast even on very large tables. The number of values and histogram bins collected is now user-settable via an ALTER TABLE command. There is more still to do; the new stats are not being used everywhere they could be in the planner. But the remaining changes for this project should be localized, and the behavior is already better than before. A not-very-related change is that sorting now makes use of btree comparison routines if it can find one, rather than invoking '<' twice.
* pgindent run. Make it all clean.Bruce Momjian2001-03-22
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