PostgreSQLはどこでsqlクエリの61を処理します

Joinの原価計算の呼び出しパス:
make_one_rel
  ->make_rel_from_joinlist
       ->standard_join_search
             -> join_search_one_level
                   -> make_join_rel
                         -> add_paths_to_joinrel
                               ->hash_inner_and_outer
                                     ->try_hashjoin_path
                                         ->initial_cost_hashjoin
make_join_rel関数には、次のコードがあります.

RelOptInfo *

make_join_rel(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)

{

    ...



        /*

     * Consider paths using each rel as both outer and inner.  Depending on

     * the join type, a provably empty outer or inner rel might mean the join

     * is provably empty too; in which case throw away any previously computed

     * paths and mark the join as dummy.  (We do it this way since it's

     * conceivable that dummy-ness of a multi-element join might only be

     * noticeable for certain construction paths.)

     *

     * Also, a provably constant-false join restriction typically means that

     * we can skip evaluating one or both sides of the join.  We do this by

     * marking the appropriate rel as dummy.  For outer joins, a

     * constant-false restriction that is pushed down still means the whole

     * join is dummy, while a non-pushed-down one means that no inner rows

     * will join so we can treat the inner rel as dummy.

     *

     * We need only consider the jointypes that appear in join_info_list, plus

     * JOIN_INNER.

     */

    switch (sjinfo->jointype)

    {

        case JOIN_INNER:



            fprintf(stderr,"JOIN_INNER 
");



            if (is_dummy_rel(rel1) || is_dummy_rel(rel2) ||

                restriction_is_constant_false(restrictlist, false))

            {

                mark_dummy_rel(joinrel);

                break;

            }

            add_paths_to_joinrel(root, joinrel, rel1, rel2,

                                 JOIN_INNER, sjinfo,

                                 restrictlist);

            add_paths_to_joinrel(root, joinrel, rel2, rel1,

                                 JOIN_INNER, sjinfo,

                                 restrictlist);

            break;

        case  JOIN_LEFT:

            ...

            break;

        case  JOIN_FULL:

            ...

            break;

        case  JOIN_SEMI:

            ...

            break;

        case  JOIN_ANTI:

            ...

            break;

         ...

     }

     ...

}