Changeset: bbd8d70e4268 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=bbd8d70e4268
Modified Files:
sql/server/rel_optimizer.c
Branch: Nov2019
Log Message:
Perform rel_push_semijoin_down and rel_push_join_down optimizers after
rel_join_order, so semijoins will be always pushed bellow regular joins
diffs (183 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
@@ -1374,7 +1374,7 @@ static sql_exp *
if (get_cmp(e) == cmp_or || get_cmp(e) == cmp_filter) {
list *l, *r;
- l = exps_push_down(sql, e->l, f, t);
+ l = exps_push_down(sql, e->l, f, t);
if (!l)
return NULL;
r = exps_push_down(sql, e->r, f, t);
@@ -1448,7 +1448,6 @@ exp_push_down(mvc *sql, sql_exp *e, sql_
return _exp_push_down(sql, e, f, t);
}
-
/* some projections results are order dependend (row_number etc) */
static int
project_unsafe(sql_rel *rel, int allow_identity)
@@ -1760,13 +1759,13 @@ rel_push_count_down(int *changes, mvc *s
if (!is_groupby(rel->op))
return rel;
- r = rel->l;
+ r = rel->l;
if (is_groupby(rel->op) && !rel_is_ref(rel) &&
- 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)) {
- sql_exp *nce, *oce;
+ 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)) {
+ sql_exp *nce, *oce;
sql_rel *gbl, *gbr; /* Group By */
sql_rel *cp; /* Cross Product */
sql_subfunc *mult;
@@ -1780,7 +1779,7 @@ rel_push_count_down(int *changes, mvc *s
rname = exp_relname(oce);
name = exp_name(oce);
- args = new_exp_list(sql->sa);
+ args = new_exp_list(sql->sa);
srel = r->l;
{
sql_subaggr *cf = sql_bind_aggr(sql->sa,
sql->session->schema, "count", NULL);
@@ -6069,7 +6068,7 @@ exps_remove_dictexps(mvc *sql, list *exp
static sql_rel *
rel_remove_join(int *changes, mvc *sql, sql_rel *rel)
{
- if (is_join(rel->op) && !is_outerjoin(rel->op) && /* DISABLES CODE */
(0)) {
+ if (is_join(rel->op) && !is_outerjoin(rel->op)) {
sql_rel *l = rel->l;
sql_rel *r = rel->r;
int lconst = 0, rconst = 0;
@@ -6100,7 +6099,7 @@ rel_remove_join(int *changes, mvc *sql,
list_merge(rel->exps, r->exps, (fdup)NULL);
}
}
- if (is_join(rel->op) && /* DISABLES CODE */ (0)) {
+ if (is_join(rel->op)) {
sql_rel *l = rel->l;
sql_rel *r = rel->r;
int ldict = 0, rdict = 0;
@@ -6137,7 +6136,7 @@ rel_remove_join(int *changes, mvc *sql,
* where non of the project_cols are from B and x=y is a foreign key
join (B is the unique side)
* and there are no filters on B
*/
- if (/* DISABLES CODE */ (0) && is_project(rel->op)) {
+ if (is_project(rel->op)) {
sql_rel *j = rel->l;
if (is_join(j->op)) {
@@ -8354,7 +8353,7 @@ add_nulls(mvc *sql, sql_rel *rel, sql_re
static sql_rel *
rel_split_outerjoin(int *changes, mvc *sql, sql_rel *rel)
{
- if (/* DISABLES CODE */ (0) && (rel->op == op_left || rel->op ==
op_right || rel->op == op_full) &&
+ if ((rel->op == op_left || rel->op == op_right || rel->op == op_full) &&
list_length(rel->exps) == 1 && exps_nr_of_or(rel->exps) ==
list_length(rel->exps)) {
sql_rel *l = rel->l, *nl, *nll, *nlr;
sql_rel *r = rel->r, *nr;
@@ -9153,13 +9152,13 @@ optimize_rel(mvc *sql, sql_rel *rel, int
* also joins between a relation and a DICT (which isn't used)
* could be removed.
* */
- if (gp.cnt[op_join] && gp.cnt[op_project])
+ if (gp.cnt[op_join] && gp.cnt[op_project] && /* DISABLES CODE */ (0))
rel = rewrite(sql, rel, &rel_remove_join, &changes);
if (gp.cnt[op_join] ||
- gp.cnt[op_left] || gp.cnt[op_right] || gp.cnt[op_full] ||
- gp.cnt[op_semi] || gp.cnt[op_anti] ||
- gp.cnt[op_select]) {
+ gp.cnt[op_left] || gp.cnt[op_right] || gp.cnt[op_full] ||
+ gp.cnt[op_semi] || gp.cnt[op_anti] ||
+ gp.cnt[op_select]) {
rel = rewrite(sql, rel, &rel_find_range, &changes);
if (value_based_opt) {
rel = rel_project_reduce_casts(&changes, sql, rel);
@@ -9179,38 +9178,15 @@ optimize_rel(mvc *sql, sql_rel *rel, int
rel = rewrite(sql, rel, &rel_rewrite_types, &changes);
- if (gp.cnt[op_anti] || gp.cnt[op_semi]) {
- /* rewrite semijoin (A, join(A,B)) into semijoin (A,B) */
- rel = rewrite(sql, rel, &rel_rewrite_semijoin, &changes);
- /* push semijoin through join */
- rel = rewrite(sql, rel, &rel_push_semijoin_down, &changes);
- /* antijoin(a, union(b,c)) -> antijoin(antijoin(a,b), c) */
- rel = rewrite(sql, rel, &rel_rewrite_antijoin, &changes);
- if (level <= 0)
- rel = rewrite_topdown(sql, rel, &rel_semijoin_use_fk,
&changes);
- }
-
- if (gp.cnt[op_left] || gp.cnt[op_right] || gp.cnt[op_full])
+ if ((gp.cnt[op_left] || gp.cnt[op_right] || gp.cnt[op_full]) && /*
DISABLES CODE */ (0))
rel = rewrite_topdown(sql, rel, &rel_split_outerjoin, &changes);
if (gp.cnt[op_select] || gp.cnt[op_project])
if (level == 1) /* only once */
rel = rewrite(sql, rel, &rel_merge_rse, &changes);
- if (gp.cnt[op_select] && gp.cnt[op_join]) {
- if (/* DISABLES CODE */ (0)) rel = rewrite_topdown(sql, rel,
&rel_push_select_down_join, &changes);
- rel = rewrite(sql, rel, &rel_remove_empty_select, &e_changes);
- }
-
- if (gp.cnt[op_join] && gp.cnt[op_groupby]) {
- rel = rewrite_topdown(sql, rel, &rel_push_count_down, &changes);
- if (level <= 0)
- rel = rewrite_topdown(sql, rel, &rel_push_join_down,
&changes);
-
- /* push_join_down introduces semijoins */
- /* rewrite semijoin (A, join(A,B)) into semijoin (A,B) */
- rel = rewrite(sql, rel, &rel_rewrite_semijoin, &changes);
- }
+ if (gp.cnt[op_select] && gp.cnt[op_join] && /* DISABLES CODE */ (0))
+ rel = rewrite_topdown(sql, rel, &rel_push_select_down_join,
&changes);
if (gp.cnt[op_select])
rel = rewrite_topdown(sql, rel, &rel_push_select_down_union,
&changes);
@@ -9218,6 +9194,9 @@ optimize_rel(mvc *sql, sql_rel *rel, int
if (gp.cnt[op_union] && gp.cnt[op_select])
rel = rewrite(sql, rel, &rel_remove_union_partitions,
&changes);
+ if (gp.cnt[op_select])
+ rel = rewrite(sql, rel, &rel_remove_empty_select, &e_changes);
+
if (gp.cnt[op_groupby]) {
rel = rewrite_topdown(sql, rel, &rel_push_aggr_down, &changes);
rel = rewrite_topdown(sql, rel, &rel_push_groupby_down,
&changes);
@@ -9240,6 +9219,28 @@ optimize_rel(mvc *sql, sql_rel *rel, int
rel = rewrite(sql, rel, &rel_merge_identical_joins, &e_changes);
}
+ /* Important -> Re-write semijoins after rel_join_order */
+ if ((gp.cnt[op_join] || gp.cnt[op_semi] || gp.cnt[op_anti]) &&
gp.cnt[op_groupby]) {
+ rel = rewrite_topdown(sql, rel, &rel_push_count_down, &changes);
+ if (level <= 0)
+ rel = rewrite_topdown(sql, rel, &rel_push_join_down,
&changes);
+
+ /* push_join_down introduces semijoins */
+ /* rewrite semijoin (A, join(A,B)) into semijoin (A,B) */
+ rel = rewrite(sql, rel, &rel_rewrite_semijoin, &changes);
+ }
+
+ if (gp.cnt[op_anti] || gp.cnt[op_semi]) {
+ /* rewrite semijoin (A, join(A,B)) into semijoin (A,B) */
+ rel = rewrite(sql, rel, &rel_rewrite_semijoin, &changes);
+ /* push semijoin through join */
+ rel = rewrite(sql, rel, &rel_push_semijoin_down, &changes);
+ /* antijoin(a, union(b,c)) -> antijoin(antijoin(a,b), c) */
+ rel = rewrite(sql, rel, &rel_rewrite_antijoin, &changes);
+ if (level <= 0)
+ rel = rewrite_topdown(sql, rel, &rel_semijoin_use_fk,
&changes);
+ }
+
/* Important -> Make sure rel_push_select_down gets called after
rel_join_order,
because pushing down select expressions makes rel_join_order more
difficult */
if (gp.cnt[op_select] || gp.cnt[op_semi]) {
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