Changeset: a870466b5aa0 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/a870466b5aa0
Modified Files:
sql/server/rel_optimizer.c
Branch: Jul2021
Log Message:
Look for outer joins, mark joins and global aggregates while finding empty
relations
diffs (36 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
@@ -5272,11 +5272,12 @@ rel_push_join_down_outer(visitor *v, sql
static int
rel_is_empty( sql_rel *rel )
{
- if ((is_join(rel->op) || is_semi(rel->op)) && !list_empty(rel->exps)) {
+ if ((is_innerjoin(rel->op) || is_left(rel->op) || is_right(rel->op) ||
is_semi(rel->op)) && !list_empty(rel->exps)) {
sql_rel *l = rel->l, *r = rel->r;
sql_exp *je;
- if (rel_is_empty(l) || rel_is_empty(r))
+ if (((is_innerjoin(rel->op) || is_left(rel->op) ||
is_semi(rel->op)) && rel_is_empty(l)) ||
+ ((is_innerjoin(rel->op) || is_right(rel->op)) &&
rel_is_empty(r)))
return 1;
/* check */
if ((je = rel_is_join_on_pkey(rel, true))) {
@@ -5287,12 +5288,13 @@ rel_is_empty( sql_rel *rel )
}
return 0;
}
- if (is_simple_project(rel->op) || is_groupby(rel->op) ||
is_select(rel->op) ||
- is_topn(rel->op) || is_sample(rel->op)) {
+ /* global aggregates always return 1 row */
+ if (is_simple_project(rel->op) || (is_groupby(rel->op) &&
!list_empty(rel->r)) || is_select(rel->op) ||
+ is_topn(rel->op) || is_sample(rel->op) || is_inter(rel->op) ||
is_except(rel->op)) {
if (rel->l)
return rel_is_empty(rel->l);
- } else if (is_join(rel->op) || is_semi(rel->op) || is_inter(rel->op) ||
is_except(rel->op)) {
- return rel_is_empty(rel->l) && rel_is_empty(rel->r);
+ } else if (is_innerjoin(rel->op) && list_empty(rel->exps)) { /*
cartesian product */
+ return rel_is_empty(rel->l) || rel_is_empty(rel->r);
}
return 0;
}
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