Changeset: ac8b887149da for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/ac8b887149da
Modified Files:
sql/server/rel_optimizer.c
Branch: Jul2021
Log Message:
Push down selections under exceptions and intersections as well.
Merged rel_push_select_down_union optimizer into rel_push_select_down, so a
selection can be pushed down further earlier.
I am committing this on Jul2021 branch because I consider this to be a bug.
diffs (128 lines):
diff --git a/sql/server/rel_optimizer.c b/sql/server/rel_optimizer.c
--- a/sql/server/rel_optimizer.c
+++ b/sql/server/rel_optimizer.c
@@ -4710,6 +4710,55 @@ rel_push_select_down(visitor *v, sql_rel
}
}
}
+
+ /* try push select under set relation */
+ if (is_select(rel->op) && r && !(rel_is_ref(r)) && !list_empty(exps)) {
+ sql_rel *u = r, *ou = u;
+ sql_rel *ul = u->l;
+ sql_rel *ur = u->r;
+
+ if (!rel_is_ref(u) && u->op == op_project)
+ u = u->l;
+
+ if (u && is_set(u->op) && !is_single(u) && !list_empty(u->exps)
&& !rel_is_ref(u)) {
+ ul = u->l;
+ ur = u->r;
+
+ ul = rel_dup(ul);
+ ur = rel_dup(ur);
+ if (!is_project(ul->op))
+ ul = rel_project(v->sql->sa, ul,
+ rel_projections(v->sql, ul, NULL, 1,
1));
+ if (!is_project(ur->op))
+ ur = rel_project(v->sql->sa, ur,
+ rel_projections(v->sql, ur, NULL, 1,
1));
+ rel_rename_exps(v->sql, u->exps, ul->exps);
+ rel_rename_exps(v->sql, u->exps, ur->exps);
+
+ if (u != ou) {
+ ul = rel_project(v->sql->sa, ul, NULL);
+ ul->exps = exps_copy(v->sql, ou->exps);
+ rel_rename_exps(v->sql, ou->exps, ul->exps);
+ set_processed(ul);
+ ur = rel_project(v->sql->sa, ur, NULL);
+ ur->exps = exps_copy(v->sql, ou->exps);
+ rel_rename_exps(v->sql, ou->exps, ur->exps);
+ set_processed(ur);
+ }
+
+ /* introduce selects under the set */
+ ul = rel_select(v->sql->sa, ul, NULL);
+ ul->exps = exps_copy(v->sql, exps);
+ ur = rel_select(v->sql->sa, ur, NULL);
+ ur->exps = exps_copy(v->sql, exps);
+
+ rel = rel_inplace_setop(v->sql, rel, ul, ur, u->op,
rel_projections(v->sql, rel, NULL, 1, 1));
+ if (need_distinct(u))
+ set_distinct(rel);
+ v->changes++;
+ }
+ }
+
return try_remove_empty_select(v, rel);
}
@@ -5475,60 +5524,6 @@ rel_join2semijoin(visitor *v, sql_rel *r
return rel;
}
-static sql_rel *
-rel_push_select_down_union(visitor *v, sql_rel *rel)
-{
- if (is_select(rel->op) && rel->l && rel->exps) {
- sql_rel *u = rel->l, *ou = u;
- sql_rel *ul = u->l;
- sql_rel *ur = u->r;
-
- if (u->op == op_project)
- u = u->l;
-
- if (!u || !is_union(u->op) || need_distinct(u) || is_single(u)
|| !u->exps || rel_is_ref(u))
- return rel;
-
- ul = u->l;
- ur = u->r;
-
- ul = rel_dup(ul);
- ur = rel_dup(ur);
- if (!is_project(ul->op))
- ul = rel_project(v->sql->sa, ul,
- rel_projections(v->sql, ul, NULL, 1, 1));
- if (!is_project(ur->op))
- ur = rel_project(v->sql->sa, ur,
- rel_projections(v->sql, ur, NULL, 1, 1));
- rel_rename_exps(v->sql, u->exps, ul->exps);
- rel_rename_exps(v->sql, u->exps, ur->exps);
-
- if (u != ou) {
- ul = rel_project(v->sql->sa, ul, NULL);
- ul->exps = exps_copy(v->sql, ou->exps);
- rel_rename_exps(v->sql, ou->exps, ul->exps);
- ur = rel_project(v->sql->sa, ur, NULL);
- ur->exps = exps_copy(v->sql, ou->exps);
- rel_rename_exps(v->sql, ou->exps, ur->exps);
- }
-
- /* introduce selects under the set (if needed) */
- set_processed(ul);
- set_processed(ur);
- if (rel_is_ref(rel) || !list_empty(rel->exps)) { /* don't
generate empty selects */
- ul = rel_select(v->sql->sa, ul, NULL);
- ul->exps = exps_copy(v->sql, rel->exps);
- ur = rel_select(v->sql->sa, ur, NULL);
- ur->exps = exps_copy(v->sql, rel->exps);
- }
-
- rel = rel_inplace_setop(v->sql, rel, ul, ur, op_union,
rel_projections(v->sql, rel, NULL, 1, 1));
- v->changes++;
- return rel;
- }
- return rel;
-}
-
static int
exp_is_rename(sql_exp *e)
{
@@ -9579,7 +9574,6 @@ rel_optimize_unions_bottomup(visitor *v,
static sql_rel *
rel_optimize_unions_topdown(visitor *v, sql_rel *rel)
{
- rel = rel_push_select_down_union(v, rel);
rel = rel_push_project_down_union(v, rel);
rel = rel_push_join_down_union(v, rel);
return rel;
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