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Replace functional-index facility with expressional indexes. Any column

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of an index can now be a computed expression instead of a simple variable.
Restrictions on expressions are the same as for predicates (only immutable
functions, no sub-selects).  This fixes problems recently introduced with
inlining SQL functions, because the inlining transformation is applied to
both expression trees so the planner can still match them up.  Along the
way, improve efficiency of handling index predicates (both predicates and
index expressions are now cached by the relcache) and fix 7.3 oversight
that didn't record dependencies of predicate expressions.
This commit is contained in:
Tom Lane
2003-05-28 16:04:02 +00:00
parent e5f19598e0
commit fc8d970cbc
50 changed files with 1351 additions and 1283 deletions
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12
src/backend/utils/adt/selfuncs.c
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@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.138 2003/05/26 00:11:27 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.139 2003/05/28 16:03:59 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -3905,14 +3905,13 @@ btcostestimate(PG_FUNCTION_ARGS)
indexSelectivity, indexCorrelation);
/*
* If it's a functional index, leave the default zero-correlation
* estimate in place. If not, and if we can get an estimate for the
* first variable's ordering correlation C from pg_statistic, estimate
* If the first column is a simple variable, and we can get an estimate
* for its ordering correlation C from pg_statistic, estimate
* the index correlation as C / number-of-columns. (The idea here is
* that multiple columns dilute the importance of the first column's
* ordering, but don't negate it entirely.)
*/
if (index->indproc == InvalidOid)
if (index->indexkeys[0] != 0)
{
Oid relid;
HeapTuple tuple;
@ -3942,8 +3941,7 @@ btcostestimate(PG_FUNCTION_ARGS)
Assert(nnumbers == 1);
varCorrelation = numbers[0];
for (nKeys = 1; index->indexkeys[nKeys] != 0; nKeys++)
/* skip */ ;
nKeys = index->ncolumns;
*indexCorrelation = varCorrelation / nKeys;