Changeset: 24ed0517e8a8 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=24ed0517e8a8
Modified Files:
sql/server/rel_unnest.c
Branch: default
Log Message:
Packing unnest re-writers
diffs (136 lines):
diff --git a/sql/server/rel_unnest.c b/sql/server/rel_unnest.c
--- a/sql/server/rel_unnest.c
+++ b/sql/server/rel_unnest.c
@@ -1645,7 +1645,7 @@ rewrite_exp_rel(visitor *v, sql_rel *rel
}
/* add an dummy true projection column */
-static sql_rel *
+static inline sql_rel *
rewrite_empty_project(visitor *v, sql_rel *rel)
{
if (is_simple_project(rel->op) && list_empty(rel->exps)) {
@@ -2000,7 +2000,7 @@ aggrs_complex(list *exps)
/* simplify aggregates, ie push functions under the groupby relation */
/* rel visitor */
-static sql_rel *
+static inline sql_rel *
rewrite_aggregates(visitor *v, sql_rel *rel)
{
if (is_groupby(rel->op) && (exps_complex(rel->r) ||
aggrs_complex(rel->exps))) {
@@ -2070,7 +2070,7 @@ rewrite_or_exp(visitor *v, sql_rel *rel)
return rel;
}
-static sql_rel *
+static inline sql_rel *
rewrite_split_select_exps(visitor *v, sql_rel *rel)
{
if (is_select(rel->op) && !list_empty(rel->exps)) {
@@ -3194,7 +3194,7 @@ rewrite_remove_xp_project(visitor *v, sq
return rel;
}
-static sql_rel *
+static inline sql_rel *
rewrite_remove_xp(visitor *v, sql_rel *rel)
{
if (rel->op == op_join && list_empty(rel->exps)) {
@@ -3262,7 +3262,7 @@ rewrite_fix_count(visitor *v, sql_rel *r
return rel;
}
-static sql_rel *
+static inline sql_rel *
rewrite_groupings(visitor *v, sql_rel *rel)
{
prop *found;
@@ -3338,8 +3338,12 @@ rewrite_groupings(visitor *v, sql_rel *r
}
append(pexps, ne);
}
+ if (list_empty(exps))
+ append(exps, exp_atom_bool(v->sql->sa,
1)); /* protection against empty projections */
nrel->exps = exps;
set_processed(nrel);
+ if (list_empty(pexps))
+ append(pexps, exp_atom_bool(v->sql->sa,
1)); /* protection against empty projections */
nrel = rel_project(v->sql->sa, nrel, pexps);
set_processed(nrel);
@@ -3386,9 +3390,13 @@ rewrite_groupings(visitor *v, sql_rel *r
}
append(pexps, ne);
}
+ if (list_empty(exps))
+ append(exps, exp_atom_bool(v->sql->sa,
1)); /* protection against empty projections */
nrel->exps = exps;
set_processed(nrel);
v->changes++;
+ if (list_empty(pexps))
+ append(pexps, exp_atom_bool(v->sql->sa,
1)); /* protection against empty projections */
nrel = rel_project(v->sql->sa, nrel, pexps);
set_processed(nrel);
return nrel;
@@ -3566,6 +3574,28 @@ rewrite_values(visitor *v, sql_rel *rel)
return rel;
}
+static sql_rel *
+rel_unnest_simplify(visitor *v, sql_rel *rel)
+{
+ /* at rel_select.c explicit cross-products generate empty selects, if
these are not used, they can be removed at rewrite_simplify */
+ rel = rewrite_empty_project(v, rel); /* remove empty project/groupby */
+ rel = rewrite_simplify(v, rel);
+ rel = rewrite_or_exp(v, rel);
+ rel = rewrite_split_select_exps(v, rel); /* has to run before
rewrite_complex */
+ rel = rewrite_aggregates(v, rel);
+ return rel;
+}
+
+static sql_rel *
+rel_unnest_projects(visitor *v, sql_rel *rel)
+{
+ /* both rewrite_values and rewrite_fix_count use 'used' property from
sql_rel, reset it, so make sure rewrite_reset_used is called first */
+ rel = rewrite_reset_used(v, rel);
+ rel = rewrite_remove_xp(v, rel); /* remove crossproducts with
project [ atom ] */
+ rel = rewrite_groupings(v, rel); /* transform group combinations
into union of group relations */
+ return rel;
+}
+
sql_rel *
rel_unnest(mvc *sql, sql_rel *rel)
{
@@ -3573,17 +3603,11 @@ rel_unnest(mvc *sql, sql_rel *rel)
visitor v = { .sql = sql, .data = &level }; /* make it compatible with
rel_optimizer, so set the level to 0 */
rel = rel_exp_visitor_bottomup(&v, rel, &rewrite_simplify_exp, false);
- /* at rel_select.c explicit cross-products generate empty selects, if
these are not used, they can be removed at rewrite_simplify */
- rel = rel_visitor_bottomup(&v, rel, &rewrite_simplify);
- rel = rel_visitor_bottomup(&v, rel, &rewrite_or_exp);
- rel = rel_visitor_bottomup(&v, rel, &rewrite_split_select_exps); /* has
to run before rewrite_complex */
-
- rel = rel_visitor_bottomup(&v, rel, &rewrite_aggregates);
+ rel = rel_visitor_bottomup(&v, rel, &rel_unnest_simplify);
rel = rel_exp_visitor_bottomup(&v, rel, &rewrite_rank, false);
rel = rel_visitor_bottomup(&v, rel, &rewrite_values);
rel = rel_visitor_bottomup(&v, rel, &rewrite_outer2inner_union);
- rel = rel_visitor_bottomup(&v, rel, &rewrite_empty_project); /* remove
empty project/groupby */
rel = rel_visitor_bottomup(&v, rel, ¬_anyequal_helper);
rel = rel_exp_visitor_bottomup(&v, rel, &rewrite_complex, true);
@@ -3595,11 +3619,7 @@ rel_unnest(mvc *sql, sql_rel *rel)
rel = rel_visitor_bottomup(&v, rel, &rewrite_simplify); /* as
expressions got merged before, lets try to simplify again */
rel = rel_visitor_bottomup(&v, rel, &_rel_unnest);
rel = rel_visitor_bottomup(&v, rel, &rewrite_fix_count); /* fix
count inside a left join (adds a project (if (cnt IS null) then (0) else (cnt))
*/
- /* both rewrite_values and rewrite_fix_count use 'used' property from
sql_rel, reset it */
- rel = rel_visitor_bottomup(&v, rel, &rewrite_reset_used);
- rel = rel_visitor_bottomup(&v, rel, &rewrite_remove_xp); /*
remove crossproducts with project [ atom ] */
- rel = rel_visitor_bottomup(&v, rel, &rewrite_groupings); /*
transform group combinations into union of group relations */
- rel = rel_visitor_bottomup(&v, rel, &rewrite_empty_project);
+ rel = rel_visitor_bottomup(&v, rel, &rel_unnest_projects);
rel = rel_exp_visitor_bottomup(&v, rel,
&exp_reset_card_and_freevar_set_physical_type, false);
return rel;
}
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