diff options
Diffstat (limited to 'src/backend/optimizer/path')
| -rw-r--r-- | src/backend/optimizer/path/costsize.c | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index 05686d01942..8577c7b1389 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -4436,21 +4436,50 @@ cost_qual_eval_walker(Node *node, cost_qual_eval_context *context) } else if (IsA(node, ScalarArrayOpExpr)) { - /* - * Estimate that the operator will be applied to about half of the - * array elements before the answer is determined. - */ ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) node; Node *arraynode = (Node *) lsecond(saop->args); QualCost sacosts; + QualCost hcosts; + int estarraylen = estimate_array_length(arraynode); set_sa_opfuncid(saop); sacosts.startup = sacosts.per_tuple = 0; add_function_cost(context->root, saop->opfuncid, NULL, &sacosts); - context->total.startup += sacosts.startup; - context->total.per_tuple += sacosts.per_tuple * - estimate_array_length(arraynode) * 0.5; + + if (OidIsValid(saop->hashfuncid)) + { + /* Handle costs for hashed ScalarArrayOpExpr */ + hcosts.startup = hcosts.per_tuple = 0; + + add_function_cost(context->root, saop->hashfuncid, NULL, &hcosts); + context->total.startup += sacosts.startup + hcosts.startup; + + /* Estimate the cost of building the hashtable. */ + context->total.startup += estarraylen * hcosts.per_tuple; + + /* + * XXX should we charge a little bit for sacosts.per_tuple when + * building the table, or is it ok to assume there will be zero + * hash collision? + */ + + /* + * Charge for hashtable lookups. Charge a single hash and a + * single comparison. + */ + context->total.per_tuple += hcosts.per_tuple + sacosts.per_tuple; + } + else + { + /* + * Estimate that the operator will be applied to about half of the + * array elements before the answer is determined. + */ + context->total.startup += sacosts.startup; + context->total.per_tuple += sacosts.per_tuple * + estimate_array_length(arraynode) * 0.5; + } } else if (IsA(node, Aggref) || IsA(node, WindowFunc)) |