Changeset: 3391fa2b099f for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/3391fa2b099f
Modified Files:
sql/server/rel_optimize_proj.c
Branch: balanced_union
Log Message:
Implements push_join_down_munion optimizer WIP 2
diffs (63 lines):
diff --git a/sql/server/rel_optimize_proj.c b/sql/server/rel_optimize_proj.c
--- a/sql/server/rel_optimize_proj.c
+++ b/sql/server/rel_optimize_proj.c
@@ -3726,10 +3726,14 @@ rel_push_join_down_munion(visitor *v, sq
!(je = rel_is_join_on_pkey(rel, aligned_pk_fk))))
return rel;
- // TODO: why? bailout for no semijoin without pkey joins
+ // TODO: why? bailout for union semijoin without pkey joins
expressions
if (is_semi(rel->op) && is_munion(l->op) && !je)
return rel;
+ /* if both sides are munions we assume that they will have the
same number of children */
+ if (is_munion(l->op) && is_munion(r->op) && list_length(l->l)
!= list_length(r->l))
+ return rel;
+
if (is_munion(l->op) && !need_distinct(l) && !is_single(l) &&
!is_munion(r->op)){
/* join(munion(a,b,c), d) -> munion(join(a,d),
join(b,d), join(c,d)) */
@@ -3756,8 +3760,41 @@ rel_push_join_down_munion(visitor *v, sq
} else if (is_munion(l->op) && !need_distinct(l) &&
!is_single(l) &&
is_munion(r->op) && !need_distinct(r) &&
!is_single(r) &&
je) {
- /* join(munion(a,b,c), union(d,e,f)) ->
munion(join(a,d), join(b,e), join(c,f)) */
- // TODO
+ /* join(munion(a,b,c), munion(d,e,f)) ->
munion(join(a,d), join(b,e), join(c,f)) */
+ list *cps = sa_list(v->sql->sa);
+ /* create pairwise joins between left and right parts.
assume eq num of parts (see earlier bailout) */
+ for (node *n = ((list*)l->l)->h, *m=((list*)r->l)->h; n
&& m; n = n->next, m = m->next) {
+ /* left part */
+ sql_rel *lp = rel_dup(n->data);
+ if (!is_project(lp->op))
+ lp = rel_project(v->sql->sa, lp,
rel_projections(v->sql, lp, NULL, 1, 1));
+ rel_rename_exps(v->sql, l->exps, lp->exps);
+ if (l != ol) {
+ lp = rel_project(v->sql->sa, lp, NULL);
+ lp->exps = exps_copy(v->sql, ol->exps);
+ set_processed(lp);
+ }
+ /* right part */
+ sql_rel *rp = rel_dup(m->data);
+ if (!is_project(rp->op))
+ rp = rel_project(v->sql->sa, rp,
rel_projections(v->sql, rp, NULL, 1, 1));
+ rel_rename_exps(v->sql, l->exps, rp->exps);
+ if (l != ol) {
+ rp = rel_project(v->sql->sa, rp, NULL);
+ rp->exps = exps_copy(v->sql, ol->exps);
+ set_processed(rp);
+ }
+ /* combine them */
+ sql_rel *cp = rel_crossproduct(v->sql->sa, lp,
rp, rel->op);
+ cp->exps = exps_copy(v->sql, exps);
+ cp->attr = exps_copy(v->sql, attr);
+ set_processed(cp);
+ cp = rel_project(v->sql->sa, cp,
rel_projections(v->sql, cp, NULL, 1, 1));
+ cps = append(cps, cp);
+ }
+ v->changes++;
+ return rel_inplace_setop_n_ary(v->sql, rel, cps,
op_munion,
+
rel_projections(v->sql, rel, NULL, 1, 1));
} else if (!is_munion(l->op) &&
is_munion(r->op) && !need_distinct(r) &&
!is_single(r) &&
!is_semi(rel->op)) {
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