Changeset: c2cf29ceb889 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/c2cf29ceb889
Modified Files:
sql/server/rel_optimize_sel.c
sql/server/rel_unnest.c
sql/test/BugTracker-2015/Tests/crash.Bug-3736.test
Branch: unnest2
Log Message:
add some extra optimization for new unnesting
diffs (truncated from 389 to 300 lines):
diff --git a/sql/server/rel_optimize_sel.c b/sql/server/rel_optimize_sel.c
--- a/sql/server/rel_optimize_sel.c
+++ b/sql/server/rel_optimize_sel.c
@@ -120,10 +120,53 @@ bind_split_select(visitor *v, global_pro
* join (L, Distinct Project(join(L,P) [ p.key == l.lkey]) [p.key]) [ p.key ==
l.lkey]
* =>
* join(L, P) [p.key==l.lkey]
+ *
+ * join(project(Ref 1 distinc) [ x as xx ], groupby( join( project(Ref 1
distinct) [ x as yy ], ZZ ) ) [ yy ] [ yy , ...]) [ xx == yy ]
+ * =>
+ * project(groupby( join( project(Ref 1 distinct) [ x as yy ], ZZ ) ) [ yy ] [
yy, .. ] ) [ yy as xx, .. ]
*/
static sql_rel *
rel_remove_redundant_join_(visitor *v, sql_rel *rel)
{
+ if (rel->op == op_join && !list_empty(rel->exps)) {
+ sql_rel *l = rel->l, *gb = rel->r;
+ if (l->l && is_project(l->op) && is_groupby(gb->op)) {
+ sql_rel *inner = l->l;
+ sql_rel *gbj = gb->l;
+ if (rel_is_ref(inner) && is_project(inner->op) &&
(need_distinct(inner) || is_groupby(inner->op)) &&
+ gbj->op == op_join && list_length(inner->r) ==
list_length(rel->exps)) {
+ sql_rel *gbjl = gbj->l, *gbjr = gbj->r;
+ if ((gbjl->l && is_project(gbjl->op) && inner
== gbjl->l) ||
+ (gbjr->l && is_project(gbjr->op) &&
inner == gbjr->l)) {
+ sql_rel *nrel = rel_project(v->sql->sa,
rel_dup(gb), rel_projections(v->sql, gb, NULL, 0, 1));
+ /* sofar expect aligned gbe and je */
+ bool found = true;
+ for (node *n = nrel->exps->h, *m =
rel->exps->h; n && m && found; n = n->next, m = m->next) {
+ sql_exp *gbe = n->data;
+ sql_exp *je = m->data;
+ if (!is_compare(je->type) ||
!is_semantics(je) || je->flag != cmp_equal) {
+ found = false;
+ break;
+ }
+ sql_exp *lje = je->l, *rje =
je->r;
+ if (lje->nid ==
gbe->alias.label) {
+ gbe->alias = rje->alias;
+ } else if (rje->nid ==
gbe->alias.label) {
+ gbe->alias = lje->alias;
+ } else {
+ found = false;
+ }
+ }
+ if (found) {
+ rel_destroy(v->sql, rel);
+ return nrel;
+ } else {
+ rel_destroy(v->sql, nrel);
+ }
+ }
+ }
+ }
+ }
if ((is_join(rel->op) || is_semi(rel->op)) && !list_empty(rel->exps)) {
sql_rel *l = rel->l, *r = rel->r, *b, *p = NULL, *j;
@@ -176,7 +219,7 @@ run_optimizer
bind_remove_redundant_join(visitor *v, global_props *gp)
{
int flag = v->sql->sql_optimizer;
- return gp->opt_cycle == 0 && gp->opt_level == 1 && (gp->cnt[op_left] ||
gp->cnt[op_right]
+ return gp->opt_cycle <= 1 && gp->opt_level == 1 && (gp->cnt[op_left] ||
gp->cnt[op_right]
|| gp->cnt[op_full] || gp->cnt[op_join] || gp->cnt[op_semi]
|| gp->cnt[op_anti]) &&
(flag & remove_redundant_join) ? rel_remove_redundant_join :
NULL;
}
@@ -1327,8 +1370,174 @@ out2inner(visitor *v, sql_rel* sel, sql_
return sel;
}
-static inline sql_rel *
-rel_out2inner(visitor *v, sql_rel *rel) {
+static bool
+exps_uses_any(list *exps, list *l)
+{
+ bool uses_any = false;
+
+ if (list_empty(exps) || list_empty(l))
+ return false;
+ for (node *n = l->h; n && !uses_any; n = n->next) {
+ sql_exp *e = n->data;
+ uses_any |= list_exps_uses_exp(exps, e) != NULL;
+ }
+ return uses_any;
+}
+
+static bool has_semantics(sql_exp *e);
+
+static bool
+exps_semantics(list *l)
+{
+ if (list_empty(l))
+ return false;
+ for(node *n = l->h; n; n = n->next) {
+ sql_exp *e = n->data;
+ if (has_semantics(e))
+ return true;
+ }
+ return false;
+}
+
+static bool
+all_semantics(list *l) /* or const */
+{
+ if (list_empty(l))
+ return false;
+ for(node *n = l->h; n; n = n->next) {
+ sql_exp *e = n->data;
+ if (!exp_is_atom(e) && !has_semantics(e))
+ return false;
+ }
+ return true;
+}
+
+static bool
+any_semantics(list *l) /* or const */
+{
+ if (list_empty(l))
+ return false;
+ for(node *n = l->h; n; n = n->next) {
+ sql_exp *e = n->data;
+ if (exp_is_atom(e) || has_semantics(e))
+ return true;
+ }
+ return false;
+}
+
+static bool
+has_semantics(sql_exp *e)
+{
+ if (is_semantics(e))
+ return true;
+ switch(e->type) {
+ case e_cmp:
+ if (e->flag == cmp_con) {
+ return all_semantics(e->l);
+ } else if (e->flag == cmp_dis) {
+ return any_semantics(e->l);
+ } else if (e->flag == cmp_in || e->flag == cmp_notin) {
+ return has_semantics(e->l) || any_semantics(e->r);
+ } else if (e->flag == cmp_filter) {
+ return any_semantics(e->l) || any_semantics(e->r);
+ } else {
+ bool semantics = has_semantics(e->l) ||
has_semantics(e->r);
+ if (e->f)
+ return true;
+ //semantics |= has_semantics(e->f);
+ return semantics;
+ }
+ case e_atom:
+ return false;
+ case e_column:
+ return false;
+ case e_aggr:
+ case e_func:
+ if (e->type == e_func) {
+ sql_subfunc *f = e->f;
+ if (f->func->semantics)
+ return true;
+ if (!f->func->s && (
+ strcmp(f->func->base.name,
"nullif") == 0 ||
+ strcmp(f->func->base.name,
"coalesce") == 0 ||
+ strcmp(f->func->base.name,
"casewhen") == 0 ||
+ strcmp(f->func->base.name,
"case") == 0 ||
+ strcmp(f->func->base.name,
"ifthenelse") == 0))
+ return true;
+ return exps_semantics(e->l);
+ }
+ return e->semantics;
+ case e_convert:
+ return has_semantics(e->l);
+ case e_psm:
+ return false;
+ }
+ return false;
+}
+
+static sql_rel *
+rel_outer2inner(visitor *v, list *exps, sql_rel *rel)
+{
+ if (!rel || rel_is_ref(rel))
+ return rel;
+ if (rel->op == op_join /*is_join(rel->op) later nested outers as well
*/ || is_select(rel->op)) {
+ rel->l = rel_outer2inner(v, exps, rel->l);
+ if (is_join(rel->op))
+ rel->r = rel_outer2inner(v, exps, rel->r);
+ } else if (is_simple_project(rel->op)) { /* handle projection
expressions */
+ /* merge/collect all exps which don't have 'is' semantics */
+ list *nexps = sa_list(v->sql->sa);
+ for(node *n = rel->exps->h; n; n = n->next) {
+ sql_exp *e = n->data;
+ if (!has_semantics(e) && list_exps_uses_exp(exps, e))
+ append(nexps, e);
+ }
+ rel->l = rel_outer2inner(v, nexps, rel->l);
+ } else if (is_left(rel->op)) { /* first just left outers */
+ list *rexps = rel_projections(v->sql, rel->r, NULL, 0, 1);
+ /* exps from right hand */
+ if (exps_uses_any(exps, rexps)) {
+ rel->op = op_join;
+ v->changes++;
+ }
+ }
+ return rel;
+}
+
+static bool
+rel_has_leftouter(sql_rel *rel)
+{
+ if (!rel || rel_is_ref(rel))
+ return false;
+ if (rel->op == op_join)
+ return rel_has_leftouter(rel->l) || rel_has_leftouter(rel->r);
+ if (is_simple_project(rel->op) || is_select(rel->op))
+ return rel_has_leftouter(rel->l);
+ if (is_left(rel->op))
+ return true;
+ return false;
+}
+
+/*
+ * Rewrite outer joins into inner joins, when results of the outer join are
later used in
+ * predicates filtering the none matching rows of the outer join.
+ *
+ * select/join(.. project(.. outer_join () )[ use exps of none-matching-side]
) [ exp using (possibly indirect)
+ * attribute of none-matching sided
+ */
+static sql_rel *
+rel_out2inner(visitor *v, sql_rel *rel)
+{
+ if (rel && (is_select(rel->op) || rel->op == op_join) &&
!list_empty(rel->exps) && rel_has_leftouter(rel)) {
+ /* collect all exps which don't have 'is' semantics */
+ list *exps = sa_list(v->sql->sa);
+ for (node *n = rel->exps->h; n; n = n->next) {
+ sql_exp *e = n->data;
+ if (!has_semantics(e))
+ append(exps, e);
+ }
+ rel = rel_outer2inner(v, exps, rel);
+ }
if (!is_non_trivial_select_applied_to_outer_join(rel)) {
// Nothing to do here.
@@ -1370,20 +1579,6 @@ rel_out2inner(visitor *v, sql_rel *rel)
}
}
-static bool
-exps_uses_any(list *exps, list *l)
-{
- bool uses_any = false;
-
- if (list_empty(exps) || list_empty(l))
- return false;
- for (node *n = l->h; n && !uses_any; n = n->next) {
- sql_exp *e = n->data;
- uses_any |= list_exps_uses_exp(exps, e) != NULL;
- }
- return uses_any;
-}
-
/* TODO At the moment I have to disable the new join2semi because the join
order optimizer doesn't take semi-joins into account,
so plans get deteriorated if more joins are optimized into semi-joins. Later I
will review the join order with semi-joins and hopefully,
I will be able to re-enable the new join2semi. */
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
@@ -3977,6 +3977,29 @@ accessing_merge(list *acc, list *nacc)
return acc;
}
+static sql_rel *
+rel_smallest(sql_rel *r, list *outer_refs)
+{
+ if (r->op != op_join || !list_empty(r->exps))
+ return r;
+ sql_rel *rl = r->l;
+ sql_rel *rr = r->r;
+ int llen = list_length(outer_refs), rlen = llen;
+ for(node *n = outer_refs->h; n; n = n->next) {
+ sql_exp *e = n->data;
+ if (rel_find_exp(rl, e)) {
+ llen--;
+ } else {
+ rlen--;
+ }
+ }
+ if (llen && rlen)
+ return r;
+ if (llen)
+ return rel_smallest(rr, outer_refs);
+ return rel_smallest(rl, outer_refs);
+}
+
static bool
rel_djoin_elim(visitor *v, sql_rel *prel, sql_rel *rel, struct unnesting
*parent, list *parent_accessing, list *refs)
{
@@ -4007,7 +4030,8 @@ rel_djoin_elim(visitor *v, sql_rel *prel
assert(p);
struct access_info *ai = p?p->value.pval:NULL;
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