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Updated cost estimation code (same logic)

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Andrew Kane
2023-06-10 10:52:29 -07:00
parent a33e72d58e
commit 629fa6f0cd
1 changed files with 7 additions and 6 deletions
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13
src/ivfflat.c
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@@ -71,7 +71,6 @@ ivfflatcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
int lists; int lists;
double ratio; double ratio;
double spc_seq_page_cost; double spc_seq_page_cost;
double seqPageRatio = 0.5;
Relation indexRel; Relation indexRel;
#if PG_VERSION_NUM < 120000 #if PG_VERSION_NUM < 120000
List *qinfos; List *qinfos;
@@ -115,18 +114,20 @@ ivfflatcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
get_tablespace_page_costs(path->indexinfo->reltablespace, NULL, &spc_seq_page_cost); get_tablespace_page_costs(path->indexinfo->reltablespace, NULL, &spc_seq_page_cost);
/* Change some page cost from random to sequential */
costs.indexTotalCost -= seqPageRatio * costs.numIndexPages * (costs.spc_random_page_cost - spc_seq_page_cost);
/* Adjust cost if needed since TOAST not included in seq scan cost */ /* Adjust cost if needed since TOAST not included in seq scan cost */
if (costs.numIndexPages > path->indexinfo->rel->pages && ratio < 0.5) if (costs.numIndexPages > path->indexinfo->rel->pages && ratio < 0.5)
{ {
/* Change rest of page cost from random to sequential */ /* Change all page cost from random to sequential */
costs.indexTotalCost -= (1 - seqPageRatio) * costs.numIndexPages * (costs.spc_random_page_cost - spc_seq_page_cost); costs.indexTotalCost -= costs.numIndexPages * (costs.spc_random_page_cost - spc_seq_page_cost);
/* Remove cost of extra pages */ /* Remove cost of extra pages */
costs.indexTotalCost -= (costs.numIndexPages - path->indexinfo->rel->pages) * spc_seq_page_cost; costs.indexTotalCost -= (costs.numIndexPages - path->indexinfo->rel->pages) * spc_seq_page_cost;
} }
else
{
/* Change some page cost from random to sequential */
costs.indexTotalCost -= 0.5 * costs.numIndexPages * (costs.spc_random_page_cost - spc_seq_page_cost);
}
/* /*
* If the list selectivity is lower than what is returned from the generic * If the list selectivity is lower than what is returned from the generic