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path: root/src/backend/optimizer/path/allpaths.c
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* Fix qual_is_pushdown_safe to not try to push down quals involving a whole-rowTom Lane2006-02-13
| | | | | | Var referencing the subselect output. While this case could possibly be made to work, it seems not worth expending effort on. Per report from Magnus Naeslund(f).
* 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 ...
* Clean up handling of inherited-table update queries, per bug reportTom Lane2004-10-02
| | | | | | | from Sebastian Böck. The fix involves being more consistent about when rangetable entries are copied or modified. Someday we really need to fix this stuff to not scribble on its input data structures in the first place...
* 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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* Repair some issues with column aliases and RowExpr construction in theTom Lane2004-08-19
| | | | | | | | | | | | presence of dropped columns. Document the already-presumed fact that eref aliases in relation RTEs are supposed to have entries for dropped columns; cause the user alias structs to have such entries too, so that there's always a one-to-one mapping to the underlying physical attnums. Adjust expandRTE() and related code to handle the case where a column that is part of a JOIN has been dropped. Generalize expandRTE()'s API so that it can be used in a couple of places that formerly rolled their own implementation of the same logic. Fix ruleutils.c to suppress display of aliases for columns that were dropped since the rule was made.
* Make the world very nearly safe for composite-type columns in tables.Tom Lane2004-06-05
| | | | | | | | | | | | | | | | | | | 1. Solve the problem of not having TOAST references hiding inside composite values by establishing the rule that toasting only goes one level deep: a tuple can contain toasted fields, but a composite-type datum that is to be inserted into a tuple cannot. Enforcing this in heap_formtuple is relatively cheap and it avoids a large increase in the cost of running the tuptoaster during final storage of a row. 2. Fix some interesting problems in expansion of inherited queries that reference whole-row variables. We never really did this correctly before, but it's now relatively painless to solve by expanding the parent's whole-row Var into a RowExpr() selecting the proper columns from the child. If you dike out the preventive check in CheckAttributeType(), composite-type columns now seem to actually work. However, we surely cannot ship them like this --- without I/O for composite types, you can't get pg_dump to dump tables containing them. So a little more work still to do.
* 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.
* Promote row expressions to full-fledged citizens of the expression syntax,Tom Lane2004-05-10
| | | | | | | | | | rather than allowing them only in a few special cases as before. In particular you can now pass a ROW() construct to a function that accepts a rowtype parameter. Internal generation of RowExprs fixes a number of corner cases that used to not work very well, such as referencing the whole-row result of a JOIN or subquery. This represents a further step in the work I started a month or so back to make rowtype values into first-class citizens.
* 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.
* Fix permission-checking bug reported by Tim Burgess 10-Feb-03 (this timeTom Lane2004-01-14
| | | | | | | | | for sure...). Rather than relying on the query context of a rangetable entry to identify what permissions it wants checked, store a full AclMode mask in each RTE, and check exactly those bits. This allows an RTE specifying, say, INSERT privilege on a view to be copied into a derived UPDATE query without changing meaning. Per recent discussion thread. initdb forced due to change of stored rule representation.
* 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.
* Repair planner failure when there are multiple IN clauses, each withTom Lane2003-12-17
| | | | | | | a join in its subselect. In this situation we *must* build a bushy plan because there are no valid left-sided or right-sided join trees. Accordingly, hoary sanity check needs an update. Per report from Alessandro Depase.
* $Header: -> $PostgreSQL Changes ...PostgreSQL Daemon2003-11-29
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* Message editing: remove gratuitous variations in message wording, standardizePeter Eisentraut2003-09-25
| | | | | terms, add some clarifications, fix some untranslatable attempts at dynamic message building.
* Code cleanup inspired by recent resname bug report (doesn't fix the bugTom Lane2003-08-11
| | | | | | | | yet, though). Avoid using nth() to fetch tlist entries; provide a common routine get_tle_by_resno() to search a tlist for a particular resno. This replaces a couple uses of nth() and a dozen hand-coded search loops. Also, replace a few uses of nth(length-1, list) with llast().
* 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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* 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 subquery qual pushdown rules so that we can push down a qualTom Lane2003-04-24
| | | | | | into a UNION that has some type coercions applied to the component queries, so long as the qual itself does not reference any columns that have such coercions. Per example from Jonathan Bartlett 24-Apr-03.
* Department of second thoughts: probably shouldn't use nth() to get theTom Lane2003-03-22
| | | | | appropriate targetlist entry out of the subquery. Use an explicit search like we do everywhere else.
* Adjust subquery qual pushdown rules to be more forgiving: if a qualTom Lane2003-03-22
| | | | | | | | | refers to a non-DISTINCT output column of a DISTINCT ON subquery, or if it refers to a function-returning-set, we cannot push it down. But the old implementation refused to push down *any* quals if the subquery had any such 'dangerous' outputs. Now we just look at the output columns actually referenced by each qual expression. More code than before, but probably no slower since we don't make unnecessary checks.
* Restructure parsetree representation of DECLARE CURSOR: now it's aTom Lane2003-03-10
| | | | | | | | | | | | utility statement (DeclareCursorStmt) with a SELECT query dangling from it, rather than a SELECT query with a few unusual fields in it. Add code to determine whether a planned query can safely be run backwards. If DECLARE CURSOR specifies SCROLL, ensure that the plan can be run backwards by adding a Materialize plan node if it can't. Without SCROLL, you get an error if you try to fetch backwards from a cursor that can't handle it. (There is still some discussion about what the exact behavior should be, but this is necessary infrastructure in any case.) Along the way, make EXPLAIN DECLARE CURSOR work.
* Turns out new IN implementation has got some problems in an UPDATE orTom Lane2003-03-05
| | | | | DELETE with inherited target table. Fix it; add a regression test. Also, correct ancient misspelling of 'inherited'.
* 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.
* Allow the planner to collapse explicit inner JOINs together, rather thanTom Lane2003-01-25
| | | | | | | | | necessarily following the JOIN syntax to develop the query plan. The old behavior is still available by setting GUC variable JOIN_COLLAPSE_LIMIT to 1. Also create a GUC variable FROM_COLLAPSE_LIMIT to control the similar decision about when to collapse sub-SELECT lists into their parent lists. (This behavior existed already, but the limit was always GEQO_THRESHOLD/2; now it's separately adjustable.)
* 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.
* Be more realistic about plans involving Materialize nodes: take theirTom Lane2002-11-30
| | | | cost into account while planning.
* Add new palloc0 call as merge of palloc and MemSet(0).Bruce Momjian2002-11-13
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* Back out use of palloc0 in place if palloc/MemSet. Seems constant lenBruce Momjian2002-11-11
| | | | to MemSet is a performance boost.
* Merge palloc()/MemSet(0) calls into a single palloc0() call.Bruce Momjian2002-11-10
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* 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.
* pgindent run.Bruce Momjian2002-09-04
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* Push down outer qualification clauses into UNION and INTERSECT subqueries.Tom Lane2002-08-29
| | | | Per pghackers discussion from back around 1-August.
* Update copyright to 2002.Bruce Momjian2002-06-20
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* Get rid of long-since-vestigial Iter node type, in favor of adding aTom Lane2002-05-12
| | | | | | | returns-set boolean field in Func and Oper nodes. This allows cleaner, more reliable tests for expressions returning sets in the planner and parser. For example, a WHERE clause returning a set is now detected and complained of in the parser, not only at runtime.
* 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 ...
* Suppress subquery pullup and pushdown when the subquery has anyTom Lane2001-12-10
| | | | | | set-returning functions in its target list. This ensures that we won't rewrite the query in a way that places set-returning functions into quals (WHERE clauses). Cf. bug reports from Joe Conway.
* New pgindent run with fixes suggested by Tom. Patch manually reviewed,Bruce Momjian2001-11-05
| | | | initdb/regression tests pass.
* 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.
* Extend code that deduces implied equality clauses to detect whether aTom Lane2001-10-18
| | | | | | | | clause being added to a particular restriction-clause list is redundant with those already in the list. This avoids useless work at runtime, and (perhaps more importantly) keeps the selectivity estimation routines from generating too-small estimates of numbers of output rows. Also some minor improvements in OPTIMIZER_DEBUG displays.
* Fix optimizer to not try to push WHERE clauses down into a sub-SELECT thatTom Lane2001-07-31
| | | | | | has a DISTINCT ON clause, per bug report from Anthony Wood. While at it, improve the DISTINCT-ON-clause recognizer routine to not be fooled by out- of-order DISTINCT lists.
* Do not push down quals into subqueries that have LIMIT/OFFSET clauses,Tom Lane2001-07-16
| | | | | since the added qual could change the set of rows that get past the LIMIT. Per discussion on pgsql-sql 7/15/01.
* 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 ...
* 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).
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