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path: root/src/backend/optimizer/prep/prepunion.c
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* Rewriter and planner should use only resno, not resname, to identifyTom Lane2003-08-11
| | | | | | | target columns in INSERT and UPDATE targetlists. Don't rely on resname to be accurate in ruleutils, either. This fixes bug reported by Donald Fraser, in which renaming a column referenced in a rule did not work very well.
* Update copyrights to 2003.Bruce Momjian2003-08-04
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* pgindent run.Bruce Momjian2003-08-04
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* A visit from the message-style police ...Tom Lane2003-07-28
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* Error message editing in backend/optimizer, backend/rewrite.Tom Lane2003-07-25
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* Another round of error message editing, covering backend/commands/.Tom Lane2003-07-20
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* Add defenses against trying to attach qual conditions to a setOperationTom Lane2003-07-16
| | | | | | query node, since that won't work unless the planner is upgraded. Someday we should try to support at least some cases of this, but for now just plug the hole in the dike. Per discussion with Dmitry Tkach.
* 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.
* Allow GROUP BY, ORDER BY, DISTINCT targets to be unknown literals,Tom Lane2003-06-16
| | | | | | | | | silently resolving them to type TEXT. This is comparable to what we do when faced with UNKNOWN in CASE, UNION, and other contexts. It gets rid of this and related annoyances: select distinct f1, '' from int4_tbl; ERROR: Unable to identify an ordering operator '<' for type unknown This was discussed many moons ago, but no one got round to fixing it.
* Implement feature of new FE/BE protocol whereby RowDescription identifiesTom Lane2003-05-06
| | | | | | | | | the column by table OID and column number, if it's a simple column reference. Along the way, get rid of reskey/reskeyop fields in Resdoms. Turns out that representation was not convenient for either the planner or the executor; we can make the planner deliver exactly what the executor wants with no more effort. initdb forced due to change in stored rule representation.
* Infrastructure for deducing Param types from context, in the same wayTom Lane2003-04-29
| | | | | | | | | | | that the types of untyped string-literal constants are deduced (ie, when coerce_type is applied to 'em, that's what the type must be). Remove the ancient hack of storing the input Param-types array as a global variable, and put the info into ParseState instead. This touches a lot of files because of adjustment of routine parameter lists, but it's really not a large patch. Note: PREPARE statement still insists on exact specification of parameter types, but that could easily be relaxed now, if we wanted to do so.
* 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.
* 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'.
* Create a distinction between Lists of integers and Lists of OIDs, to getTom Lane2003-02-09
| | | | | | 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.
* 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.
* 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.
* Adjust API of expression_tree_mutator and query_tree_mutator toTom Lane2003-01-17
| | | | | | simplify callers. It turns out the common case is that the caller does want to recurse into sub-queries, so push support for that into these subroutines.
* Allow merge and hash joins to occur on arbitrary expressions (anything notTom Lane2003-01-15
| | | | | | | | | | | | | | | | containing a volatile function), rather than only on 'Var = Var' clauses as before. This makes it practical to do flatten_join_alias_vars at the start of planning, which in turn eliminates a bunch of klugery inside the planner to deal with alias vars. As a free side effect, we now detect implied equality of non-Var expressions; for example in SELECT ... WHERE a.x = b.y and b.y = 42 we will deduce a.x = 42 and use that as a restriction qual on a. Also, we can remove the restriction introduced 12/5/02 to prevent pullup of subqueries whose targetlists contain sublinks. Still TODO: make statistical estimation routines in selfuncs.c and costsize.c smarter about expressions that are more complex than plain Vars. The need for this is considerably greater now that we have to be able to estimate the suitability of merge and hash join techniques on such expressions.
* Revise cost_qual_eval() to compute both startup (one-time) and per-tupleTom Lane2003-01-12
| | | | | | costs for expression evaluation, not only per-tuple cost as before. This extension is needed in order to deal realistically with hashed or materialized sub-selects.
* Fix inherited UPDATE for cases where child column numbering doesn'tTom Lane2003-01-05
| | | | | | match parent table. This used to work, but was broken in 7.3 by rearrangement of code that handles targetlist sorting. Add a regression test to catch future breakage.
* Clean up plantree representation of SubPlan-s --- SubLink does not appearTom Lane2002-12-14
| | | | | | | | in the planned representation of a subplan at all any more, only SubPlan. This means subselect.c doesn't scribble on its input anymore, which seems like a good thing; and there are no longer three different possible interpretations of a SubLink. Simplify node naming and improve comments in primnodes.h. No change to stored rules, though.
* 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.
* Remove unused constisset and constiscast fields of Const nodes. CleanTom Lane2002-11-25
| | | | up code and documentation associated with Param nodes.
* Extend pg_cast castimplicit column to a three-way value; this allows usTom Lane2002-09-18
| | | | | | | | | | | | | | | | | | | | | | | | to be flexible about assignment casts without introducing ambiguity in operator/function resolution. Introduce a well-defined promotion hierarchy for numeric datatypes (int2->int4->int8->numeric->float4->float8). Change make_const to initially label numeric literals as int4, int8, or numeric (never float8 anymore). Explicitly mark Func and RelabelType nodes to indicate whether they came from a function call, explicit cast, or implicit cast; use this to do reverse-listing more accurately and without so many heuristics. Explicit casts to char, varchar, bit, varbit will truncate or pad without raising an error (the pre-7.2 behavior), while assigning to a column without any explicit cast will still raise an error for wrong-length data like 7.3. This more nearly follows the SQL spec than 7.2 behavior (we should be reporting a 'completion condition' in the explicit-cast cases, but we have no mechanism for that, so just do silent truncation). Fix some problems with enforcement of typmod for array elements; it didn't work at all in 'UPDATE ... SET array[n] = foo', for example. Provide a generalized array_length_coerce() function to replace the specialized per-array-type functions that used to be needed (and were missing for NUMERIC as well as all the datetime types). Add missing conversions int8<->float4, text<->numeric, oid<->int8. initdb forced.
* Tweak querytree-dependency-extraction code so that columns of tablesTom Lane2002-09-11
| | | | | | | | | that are explicitly JOINed are not considered dependencies unless they are actually used in the query: mere presence in the joinaliasvars list of a JOIN RTE doesn't count as being used. The patch touches a number of files because I needed to generalize the API of query_tree_walker to support an additional flag bit, but the changes are otherwise quite small.
* pgindent run.Bruce Momjian2002-09-04
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* Remove sys/types.h in files that include postgres.h, and hence c.h,Bruce Momjian2002-09-02
| | | | because c.h has sys/types.h.
* Push down outer qualification clauses into UNION and INTERSECT subqueries.Tom Lane2002-08-29
| | | | Per pghackers discussion from back around 1-August.
* ALTER TABLE DROP COLUMN works. Patch by Christopher Kings-Lynne,Tom Lane2002-08-02
| | | | | | | | | | code review by Tom Lane. Remaining issues: functions that take or return tuple types are likely to break if one drops (or adds!) a column in the table defining the type. Need to think about what to do here. Along the way: some code review for recent COPY changes; mark system columns attnotnull = true where appropriate, per discussion a month ago.
* Update copyright to 2002.Bruce Momjian2002-06-20
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* A little further progress on schemas: push down RangeVars intoTom Lane2002-03-22
| | | | | | | addRangeTableEntry calls. Remove relname field from RTEs, since it will no longer be a useful unique identifier of relations; we want to encourage people to rely on the relation OID instead. Further work on dumping qual expressions in EXPLAIN, too.
* Restructure representation of join alias variables. An explicit JOINTom Lane2002-03-12
| | | | | | | | | | | | | | | now has an RTE of its own, and references to its outputs now are Vars referencing the JOIN RTE, rather than CASE-expressions. This allows reverse-listing in ruleutils.c to use the correct alias easily, rather than painfully reverse-engineering the alias namespace as it used to do. Also, nested FULL JOINs work correctly, because the result of the inner joins are simple Vars that the planner can cope with. This fixes a bug reported a couple times now, notably by Tatsuo on 18-Nov-01. The alias Vars are expanded into COALESCE expressions where needed at the very end of planning, rather than during parsing. Also, beginnings of support for showing plan qualifier expressions in EXPLAIN. There are probably still cases that need work. initdb forced due to change of stored-rule representation.
* Previous patch to mark UNION outputs with common typmod (if any) breaksTom Lane2002-03-05
| | | | | | three-or-more-way UNIONs, as per example from Josh Berkus. Cause is a fragile assumption that one tlist's entries will exactly match another. Restructure code to make that assumption a little less fragile.
* Second thoughts dept: arrange to cache mergejoin scan selectivityTom Lane2002-03-01
| | | | in RestrictInfo nodes, instead of recomputing on every use.
* If the inputs of a UNION/INTERSECT/EXCEPT construct all agree on theTom Lane2001-11-12
| | | | | | typmod of a particular column, mark the output with that same typmod, not -1 as formerly. -1 is still used if there is any disagreement. Part of response to bug#513.
* 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.
* Fix brokenness of nested EXCEPT/INTERSECT queries. prepunion was beingTom Lane2001-08-14
| | | | | | a tad sloppy about generating the targetlist for some nodes, by generating a tlist entry that claimed to be a constant when the value wasn't actually constant. This caused setrefs.c to do the wrong thing later on.
* 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.
* Quick hack to fix Oliver Elphick's problem with subselects in anTom Lane2001-03-27
| | | | | | | inheritance query: make duplicate copies of subplans in adjust_inherited_attrs. When we redesign querytrees we really gotta do something about this issue of whether querytrees are read-only and can share substructure or not.
* pgindent run. Make it all clean.Bruce Momjian2001-03-22
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* Change Copyright from PostgreSQL, Inc to PostgreSQL Global Development Group.Bruce Momjian2001-01-24
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* Change lcons(x, NIL) to makeList(x) where appropriate.Bruce Momjian2001-01-17
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* Planner speedup hacking. Avoid saving useless pathkeys, so that pathTom Lane2000-12-14
| | | | | | | | | | | | comparison does not consider paths different when they differ only in uninteresting aspects of sort order. (We had a special case of this consideration for indexscans already, but generalize it to apply to ordered join paths too.) Be stricter about what is a canonical pathkey to allow faster pathkey comparison. Cache canonical pathkeys and dispersion stats for left and right sides of a RestrictInfo's clause, to avoid repeated computation. Total speedup will depend on number of tables in a query, but I see about 4x speedup of planning phase for a sample seven-table query.
* Cache eval cost of qualification expressions in RestrictInfo nodes toTom Lane2000-12-12
| | | | | | | avoid repeated evaluations in cost_qual_eval(). This turns out to save a useful fraction of planning time. No change to external representation of RestrictInfo --- although that node type doesn't appear in stored rules anyway.
* Restructure handling of inheritance queries so that they work with outerTom Lane2000-11-12
| | | | | | | | | | | | | | | | | joins, and clean things up a good deal at the same time. Append plan node no longer hacks on rangetable at runtime --- instead, all child tables are given their own RT entries during planning. Concept of multiple target tables pushed up into execMain, replacing bug-prone implementation within nodeAppend. Planner now supports generating Append plans for inheritance sets either at the top of the plan (the old way) or at the bottom. Expanding at the bottom is appropriate for tables used as sources, since they may appear inside an outer join; but we must still expand at the top when the target of an UPDATE or DELETE is an inheritance set, because we actually need a different targetlist and junkfilter for each target table in that case. Fortunately a target table can't be inside an outer join... Bizarre mutual recursion between union_planner and prepunion.c is gone --- in fact, union_planner doesn't really have much to do with union queries anymore, so I renamed it grouping_planner.
* Repair some bugs in new union/intersect/except code.Tom Lane2000-11-09
| | | | Thanks to Kevin O'Gorman for finding these...