diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2003-01-12 22:35:29 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2003-01-12 22:35:29 +0000 |
| commit | d4ce5a4f4c3516e88fa34c53bcc7313db90a3c08 (patch) | |
| tree | 4c6b53e1c1e0989a9f45fe42ab6f29ffac019c03 /doc/src | |
| parent | d51260aa9d36653f4d63e6df133ddff8380f61b2 (diff) | |
Revise cost_qual_eval() to compute both startup (one-time) and per-tuple
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.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/indexcost.sgml | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/doc/src/sgml/indexcost.sgml b/doc/src/sgml/indexcost.sgml index 63cf8daf22d..2e62280a8be 100644 --- a/doc/src/sgml/indexcost.sgml +++ b/doc/src/sgml/indexcost.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/Attic/indexcost.sgml,v 2.12 2002/08/22 00:01:40 tgl Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/Attic/indexcost.sgml,v 2.13 2003/01/12 22:35:29 tgl Exp $ --> <chapter id="indexcost"> @@ -237,9 +237,10 @@ amcostestimate (Query *root, * Also, we charge for evaluation of the indexquals at each index tuple. * All the costs are assumed to be paid incrementally during the scan. */ - *indexStartupCost = 0; + cost_qual_eval(&index_qual_cost, indexQuals); + *indexStartupCost = index_qual_cost.startup; *indexTotalCost = numIndexPages + - (cpu_index_tuple_cost + cost_qual_eval(indexQuals)) * numIndexTuples; + (cpu_index_tuple_cost + index_qual_cost.per_tuple) * numIndexTuples; </programlisting> </para> </step> |