Function build_child_join_rel

src/backend/optimizer/util/relnode.c:1222–1357

* build_child_join_rel * Builds RelOptInfo representing join between given two child relations. * * 'outer_rel' and 'inner_rel' are the RelOptInfos of child relations being * joined * 'parent_joinrel' is the RelOptInfo representing the join between parent * relations. Some of the members of new RelOptInfo are produced by * translating corresponding members of this RelOptInfo * 'sjinfo

 * 'jointype' is the join type (inner, left, full, etc)
 */
RelOptInfo *
build_child_join_rel(PlannerInfo *root, RelOptInfo *outer_rel,
					 RelOptInfo *inner_rel, RelOptInfo *parent_joinrel,
					 List *restrictlist, SpecialJoinInfo *sjinfo,
					 JoinType jointype)
{
	RelOptInfo *joinrel = makeNode(RelOptInfo);
	AppendRelInfo **appinfos;
	int			nappinfos;

	/* Only joins between "other" relations land here. */
	Assert(IS_OTHER_REL(outer_rel) && IS_OTHER_REL(inner_rel));

	/* The parent joinrel should have consider_partitionwise_join set. */
	Assert(parent_joinrel->consider_partitionwise_join);

	joinrel->reloptkind = RELOPT_OTHER_JOINREL;
	joinrel->relids = bms_union(outer_rel->relids, inner_rel->relids);
	joinrel->rows = 0;
	/* cheap startup cost is interesting iff not all tuples to be retrieved */
	joinrel->consider_startup = (root->tuple_fraction > 0);
	joinrel->consider_param_startup = false;
	joinrel->consider_parallel = false;
	joinrel->reltarget = create_empty_pathtarget();
	joinrel->pathlist = NIL;
	joinrel->ppilist = NIL;
	joinrel->partial_pathlist = NIL;
	joinrel->cheapest_startup_path = NULL;
	joinrel->cheapest_total_path = NULL;
	joinrel->cheapest_unique_path = NULL;
	joinrel->cheapest_parameterized_paths = NIL;
	joinrel->direct_lateral_relids = NULL;
	joinrel->lateral_relids = NULL;
	joinrel->relid = 0;			/* indicates not a baserel */
	joinrel->rtekind = RTE_JOIN;
	joinrel->min_attr = 0;
	joinrel->max_attr = 0;
	joinrel->attr_needed = NULL;
	joinrel->attr_widths = NULL;
	joinrel->lateral_vars = NIL;
	joinrel->lateral_referencers = NULL;
	joinrel->indexlist = NIL;
	joinrel->pages = 0;
	joinrel->tuples = 0;
	joinrel->allvisfrac = 0;
	joinrel->eclass_indexes = NULL;
	joinrel->subroot = NULL;
	joinrel->subplan_params = NIL;
	joinrel->amflags = 0;
	joinrel->serverid = InvalidOid;
	joinrel->segSeverids = NIL;
	joinrel->userid = InvalidOid;
	joinrel->useridiscurrent = false;
	joinrel->fdwroutine = NULL;
	joinrel->fdw_private = NULL;
	joinrel->baserestrictinfo = NIL;
	joinrel->baserestrictcost.startup = 0;
	joinrel->baserestrictcost.per_tuple = 0;