繼續分析
/* * final_cost_hashjoin * Final estimate of the cost and result size of a hashjoin path. * * Note: the numbatches estimate is also saved into 'path' for use later * * 'path' is already filled in except for the rows and cost fields and * num_batches * 'workspace' is the result from initial_cost_hashjoin * 'sjinfo' is extra info about the join for selectivity estimation * 'semifactors' contains valid data if path->jointype is SEMI or ANTI */ void final_cost_hashjoin(PlannerInfo *root, HashPath *path, JoinCostWorkspace *workspace, SpecialJoinInfo *sjinfo, SemiAntiJoinFactors *semifactors) { Path *outer_path = path->jpath.outerjoinpath; Path *inner_path = path->jpath.innerjoinpath; double outer_path_rows = outer_path->rows; double inner_path_rows = inner_path->rows; List *hashclauses = path->path_hashclauses; Cost startup_cost = workspace->startup_cost; Cost run_cost = workspace->run_cost; int numbuckets = workspace->numbuckets; int numbatches = workspace->numbatches; Cost cpu_per_tuple; QualCost hash_qual_cost; QualCost qp_qual_cost; double hashjointuples; double virtualbuckets; Selectivity innerbucketsize; ListCell *hcl;
...
qp_qual_cost.startup -= hash_qual_cost.startup;
qp_qual_cost.per_tuple -= hash_qual_cost.per_tuple;
...
}