MonetDB: default - rel_push_count_down optimizer can join the ot...

[Pedro Ferreira]

Changeset: c990d96ff45b for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=c990d96ff45b
Modified Files:
        sql/server/rel_optimizer.c
Branch: default
Log Message:

rel_push_count_down optimizer can join the other group by optimizers


diffs (61 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
@@ -1593,17 +1593,13 @@ rel_push_func_down(visitor *v, sql_rel *
  *                                                   ) [ sql_mul(.., .. NOT 
NULL) ]
  *                                              )
  */
-static sql_rel *
+static inline sql_rel *
 rel_push_count_down(visitor *v, sql_rel *rel)
 {
-       sql_rel *r;
-
-       if (!is_groupby(rel->op))
-               return rel;
-
-       r = rel->l;
-
-       if (is_groupby(rel->op) && !rel_is_ref(rel) && list_empty(rel->r) &&
+       sql_rel *r = rel->l;
+
+       assert(is_groupby(rel->op));
+       if (!rel_is_ref(rel) && list_empty(rel->r) &&
                r && !r->exps && r->op == op_join && !(rel_is_ref(r)) &&
                /* currently only single count aggregation is handled, no other 
projects or aggregation */
                list_length(rel->exps) == 1 && 
exp_aggr_is_count(rel->exps->h->data)) {
@@ -6183,6 +6179,7 @@ rel_optimize_group_by(visitor *v, sql_re
        rel = rel_groupby_order(v, rel);
        rel = rel_reduce_groupby_exps(v, rel);
        rel = rel_groupby_distinct(v, rel);
+       rel = rel_push_count_down(v, rel);
        return rel;
 }
 
@@ -9754,21 +9751,12 @@ optimize_rel(mvc *sql, sql_rel *rel, int
                        rel = rel_visitor_bottomup(&v, rel, 
&rel_join_push_exps_down);
        }
 
+       /* push_join_down introduces semijoins */
+       /* rewrite semijoin (A, join(A,B)) into semijoin (A,B) */
+       if (level <= 0 && gp.cnt[op_groupby] && (gp.cnt[op_join] || 
gp.cnt[op_semi] || gp.cnt[op_anti] || gp.cnt[op_left]))
+               rel = rel_visitor_topdown(&v, rel, &rel_push_join_down);
+
        /* Important -> Re-write semijoins after rel_join_order */
-       if ((gp.cnt[op_join] || gp.cnt[op_semi] || gp.cnt[op_anti] || 
gp.cnt[op_left] || gp.cnt[op_right]) && gp.cnt[op_groupby]) {
-               if (gp.cnt[op_join])
-                       rel = rel_visitor_topdown(&v, rel, 
&rel_push_count_down);
-               if (level <= 0) {
-                       if (gp.cnt[op_select])
-                               rel = rel_visitor_topdown(&v, rel, 
&rel_push_select_down);
-                       if (gp.cnt[op_join] || gp.cnt[op_semi] || 
gp.cnt[op_anti] || gp.cnt[op_left]) {
-                               /* push_join_down introduces semijoins */
-                               /* rewrite semijoin (A, join(A,B)) into 
semijoin (A,B) */
-                               rel = rel_visitor_topdown(&v, rel, 
&rel_push_join_down); /* rel_rewrite_semijoin will run in the next iteration */
-                       }
-               }
-       }
-
        if (gp.cnt[op_anti] || gp.cnt[op_semi]) {
                rel = rel_visitor_bottomup(&v, rel, 
&rel_optimize_semi_and_anti);
                if (level <= 0)
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