Changeset: 8100aad4d63e for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/8100aad4d63e
Modified Files:
sql/server/rel_optimize_proj.c
Branch: Dec2023
Log Message:
only rewrite project if needed (in this case if some expressions point to the
same inner column)
diffs (51 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
@@ -456,22 +456,36 @@ rel_push_project_up_(visitor *v, sql_rel
* project () [ i.i L1, i.i L2 ] -> project() [ i.i L1, L1 L2 ]
*/
if (list_length(rel->exps) > 1) {
list *exps = rel->exps;
- rel->exps = sa_list(v->sql->sa);
node *n = exps->h;
- list_append(rel->exps, n->data);
- for(n = n->next; n; n = n->next) {
+ bool needed = false;
+ for(n = n->next; n && !needed; n = n->next) {
sql_exp *e = n->data;
if (e->type == e_column && !is_selfref(e)) {
- node *m = list_find(rel->exps, e,
(fcmp)&exp_match_exp_cmp);
- if (m) {
- sql_exp *ne = exp_ref(v->sql,
m->data);
- exp_setname(v->sql->sa, ne,
exp_relname(e), exp_name(e));
- exp_propagate(v->sql->sa, ne,
e);
- set_selfref(ne);
- e = ne;
+ for(node *m = exps->h; m && m != n &&
!needed; m = m->next) {
+ sql_exp *h = m->data;
+ if (exp_match_exp(h,e))
+ needed = true;
}
}
- list_append(rel->exps, e);
+ }
+ if (needed) {
+ rel->exps = sa_list(v->sql->sa);
+ node *n = exps->h;
+ list_append(rel->exps, n->data);
+ for(n = n->next; n; n = n->next) {
+ sql_exp *e = n->data;
+ if (e->type == e_column &&
!is_selfref(e)) {
+ node *m = list_find(rel->exps,
e, (fcmp)&exp_match_exp_cmp);
+ if (m) {
+ sql_exp *ne =
exp_ref(v->sql, m->data);
+ exp_setname(v->sql->sa,
ne, exp_relname(e), exp_name(e));
+
exp_propagate(v->sql->sa, ne, e);
+ set_selfref(ne);
+ e = ne;
+ }
+ }
+ list_append(rel->exps, e);
+ }
}
}
}
_______________________________________________
checkin-list mailing list -- [email protected]
To unsubscribe send an email to [email protected]
