Changeset: fcf36ca9522e for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/fcf36ca9522e
Modified Files:
sql/server/rel_statistics.c
Branch: properties
Log Message:
If the right side of an intersection is empty, the result is empty. Also
attempt to propagate counts at joins if one of the sides is unknown
diffs (86 lines):
diff --git a/sql/server/rel_statistics.c b/sql/server/rel_statistics.c
--- a/sql/server/rel_statistics.c
+++ b/sql/server/rel_statistics.c
@@ -709,8 +709,10 @@ rel_get_statistics_(visitor *v, sql_rel
set_count_prop(v->sql->sa, rel, 0);
} else if (can_be_pruned && lv == 0 &&
!rel_is_ref(rel)) { /* left side empty */
rel = set_setop_side(v, rel, r);
+ empty_cross = false; /* don't rewrite again */
} else if (can_be_pruned && rv == 0 &&
!rel_is_ref(rel)) { /* right side empty */
rel = set_setop_side(v, rel, l);
+ empty_cross = false; /* don't rewrite again */
} else if (lv != BUN_NONE && rv != BUN_NONE) {
set_count_prop(v->sql->sa, rel, (rv > (BUN_MAX
- lv)) ? BUN_MAX : (lv + rv)); /* overflow check */
}
@@ -723,8 +725,18 @@ rel_get_statistics_(visitor *v, sql_rel
empty_cross = true;
else
set_count_prop(v->sql->sa, rel, 0);
- } else if (can_be_pruned && !empty_cross && rv == 0 &&
!rel_is_ref(rel)) { /* right side empty */
- rel = set_setop_side(v, rel, l);
+ } else if (rv == 0) { /* right side empty */
+ if (is_inter(rel->op)) {
+ if (can_be_pruned)
+ empty_cross = true;
+ else
+ set_count_prop(v->sql->sa, rel,
0);
+ } else if (can_be_pruned && !rel_is_ref(rel)) {
+ rel = set_setop_side(v, rel, l);
+ empty_cross = false; /* don't rewrite
again */
+ } else {
+ set_count_prop(v->sql->sa, rel, lv);
+ }
} else {
set_count_prop(v->sql->sa, rel, lv);
}
@@ -741,7 +753,7 @@ rel_get_statistics_(visitor *v, sql_rel
}
list_hash_clear(rel->exps);
sql_rel *l = rel_project(v->sql->sa, NULL, rel->exps);
- set_count_prop(v->sql->sa, l, 0);
+ set_count_prop(v->sql->sa, l, 1);
l = rel_select(v->sql->sa, l, exp_atom_bool(v->sql->sa,
0));
set_count_prop(v->sql->sa, l, 0);
rel->op = op_project;
@@ -809,25 +821,23 @@ rel_get_statistics_(visitor *v, sql_rel
set_count_prop(v->sql->sa, rel,
join_idx_estimate);
} else if (uniques_estimate != BUN_MAX) {
set_count_prop(v->sql->sa, rel,
uniques_estimate);
+ } else if (list_length(rel->exps) == 1 &&
(exp_is_false(rel->exps->h->data) || exp_is_null(rel->exps->h->data))) {
+ /* corner cases for outer joins */
+ if (is_left(rel->op)) {
+ set_count_prop(v->sql->sa, rel, lv);
+ } else if (is_right(rel->op)) {
+ set_count_prop(v->sql->sa, rel, rv);
+ } else if (is_full(rel->op) && lv != BUN_NONE
&& rv != BUN_NONE) {
+ set_count_prop(v->sql->sa, rel, (rv >
(BUN_MAX - lv)) ? BUN_MAX : (lv + rv)); /* overflow check */
+ } else if (lv != BUN_NONE && rv != BUN_NONE) {
+ set_count_prop(v->sql->sa, rel, 0);
+ }
+ } else if (lv == 0) {
+ set_count_prop(v->sql->sa, rel,
(is_right(rel->op) || is_full(rel->op)) ? rv : 0);
+ } else if (rv == 0) {
+ set_count_prop(v->sql->sa, rel,
(is_left(rel->op) || is_full(rel->op)) ? lv : 0);
} else if (lv != BUN_NONE && rv != BUN_NONE) {
- if (list_length(rel->exps) == 1 &&
(exp_is_false(rel->exps->h->data) || exp_is_null(rel->exps->h->data))) {
- /* corner cases for outer joins */
- if (is_left(rel->op)) {
- set_count_prop(v->sql->sa, rel,
lv);
- } else if (is_right(rel->op)) {
- set_count_prop(v->sql->sa, rel,
rv);
- } else if (is_full(rel->op)) {
- set_count_prop(v->sql->sa, rel,
(rv > (BUN_MAX - lv)) ? BUN_MAX : (lv + rv)); /* overflow check */
- } else {
- set_count_prop(v->sql->sa, rel,
0);
- }
- } else if (lv == 0) {
- set_count_prop(v->sql->sa, rel,
(is_right(rel->op) || is_full(rel->op)) ? rv : 0);
- } else if (rv == 0) {
- set_count_prop(v->sql->sa, rel,
(is_left(rel->op) || is_full(rel->op)) ? lv : 0);
- } else {
- set_count_prop(v->sql->sa, rel, (rv >
(BUN_MAX / lv)) ? BUN_MAX : (lv * rv)); /* overflow check */
- }
+ set_count_prop(v->sql->sa, rel, (rv > (BUN_MAX
/ lv)) ? BUN_MAX : (lv * rv)); /* overflow check */
}
} break;
case op_anti: {
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