MonetDB: default - optimize out 'select true'

[Niels Nes]

Changeset: feef4e0f5995 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=feef4e0f5995
Modified Files:
        sql/server/rel_optimizer.c
Branch: default
Log Message:

optimize out 'select true'
fixed endless loop in optimizer when to expressions point back to
each other.


diffs (28 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
@@ -2105,7 +2105,8 @@ exp_shares_exps( sql_exp *e, list *share
                                *uses &= used;
                                return 0;
                        }
-                       if (ne && ne != e) /* maybe ne refers to a local 
complex exp */
+                       if (ne && ne != e && (list_position(shared, e) < 0 || 
list_position(shared, e) > list_position(shared, ne))) 
+                               /* maybe ne refers to a local complex exp */
                                return exp_shares_exps( ne, shared, uses);
                        return 0;
                }
@@ -5764,6 +5765,14 @@ rel_simplify_predicates(int *changes, mv
                for (n = rel->exps->h; n; n = n->next) {
                        sql_exp *e = n->data;
 
+                       if (is_atom(e) && e->l) { /* direct literal */
+                               atom *a = e->l;
+                               int flag = a->data.val.bval;
+
+                               /* remove simple select true expressions */
+                               if (flag)
+                                       break;
+                       }
                        if (e->type == e_cmp && get_cmp(e) == cmp_equal) {
                                sql_exp *l = e->l;
                                sql_exp *r = e->r;
_______________________________________________
checkin-list mailing list
checkin-list@monetdb.org
https://www.monetdb.org/mailman/listinfo/checkin-list