Changeset: 8d7615bb914b for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/8d7615bb914b
Modified Files:
sql/server/rel_optimize_sel.c
Branch: cmp-or-patterns
Log Message:
Adds multi multivalue cmp_eq exp optimizer WIP
diffs (143 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
@@ -518,11 +518,117 @@ exp_unique_id(sql_exp *e)
return e->nid ? e->nid : e->alias.label;
}
+static inline int
+exp_cmp_eq_unique_id(sql_exp *e)
+{
+ return exp_unique_id(e->l);
+}
+
typedef struct exp_eq_atoms {
sql_exp* e;
list *l;
} ea;
+typedef struct exp_eq_multi_cols_atoms {
+ char *cs; /* col(rname, name) concat str */
+ list *ces; /* list of col exps */
+ list *gvs; /* list of lists of atoms */
+} mca;
+
+static bool
+detect_multivalue_cmp_eqs(mvc *sql, list *ands, sql_hash *meqh)
+{
+ /* we get as input a list of AND associated expressions (hence the
entries are lists themselves)
+ * we need to detect cmp_eq-only AND-associated expressions with the
same columns so we can
+ * group together their values
+ * e.g. [[n = 1, m = 10], [m = 20, k = 100, l = 3000], [m = 20, n = 2]]
has
+ * - (m,k,l) group with a single value (20, 100, 3000)
+ * - (n,k) group with two values (1, 10) and (2, 20)
+ * at the end we return true only if we have at least a group of
columns with more than a single value
+ * e.g. in this example (n,k)
+ */
+ bool multi_multivalue_cmp_eq = false;
+ for (node *n = ands->h; n; n = n->next) {
+ bool eq_only = true;
+ list *l = n->data;
+
+ /* check if this list has only cmp_eq with a column lhs and an
atom rhs */
+ for (node *m = l->h; m && eq_only; m = m->next) {
+ sql_exp *se = m->data;
+ sql_exp *le = se->l, *re = se->r;
+ eq_only &= (se->type == e_cmp && se->flag == cmp_equal
&& le->card != CARD_ATOM && is_column(le->type) && re->card == CARD_ATOM &&
!is_semantics(se));
+ }
+
+ if (!eq_only)
+ continue;
+ else {
+ /* sort the list of the cmp_eq expressions based on the
col exp
+ * NOTE: from now on we only work with the sorted list,
sl */
+ list *sl = list_sort(l,
(fkeyvalue)&exp_cmp_eq_unique_id, NULL);
+ list_append_before(ands, n, sl);
+ list_remove_node(ands, NULL, n);
+
+ /* make a hash key out of the concat str of (rname1,
name1, rname2, name2..) */
+ char *cs = "";
+ for (node *m = sl->h; m; m = m->next) {
+ sql_exp *col_exp = ((sql_exp*)m->data)->l;
+ cs = strconcat(cs,
strconcat(col_exp->alias.rname, col_exp->alias.name));
+ }
+
+ /* find the eq exp in the hash and append the values */
+ bool found = false;
+
+ int key = meqh->key(cs);
+ sql_hash_e *he = meqh->buckets[key&(meqh->size-1)];
+
+ for (;he && !found; he = he->chain) {
+ /* compare the values of the hash_entry with
the cols under cmp_eq from the list */
+ bool same_cols = true;
+ mca *mcas = he->value;
+ for (node *m = sl->h, *k = mcas->ces->h; m && k
&& same_cols; m = m->next, k = k->next) {
+ sql_exp *col_exp =
((sql_exp*)m->data)->l;
+ if (exp_equal(col_exp, k->data))
+ same_cols = false;
+ }
+ if (same_cols) {
+ /* we found the same multi cmp_eq exp
in ands list multiple times! */
+ found = multi_multivalue_cmp_eq = true;
+ /* gather all the values of the list
and add them to the hash entry */
+ list *atms = sa_list(sql->sa);
+ for (node *m = sl->h; m; m = m->next) {
+ sql_exp *val_exp =
((sql_exp*)m->data)->r;
+ atms = append(atms,
(atom*)val_exp->l);
+ }
+ mcas->gvs = append(mcas->gvs, atms);
+ }
+ }
+
+ if (!found) {
+ mca *mcas = SA_NEW(sql->sa, mca);
+ mcas->cs = cs;
+ mcas->ces = sa_list(sql->sa);
+ for (node *m = sl->h; m; m = m->next) {
+ sql_exp *col_exp =
((sql_exp*)m->data)->l;
+ mcas->ces = append(mcas->ces, col_exp);
+ }
+ /* for (group values) gv create a list and
append it to the gvs list */
+ list *atms = sa_list(sql->sa);
+ for (node *m = sl->h; m; m = m->next) {
+ sql_exp *val_exp =
((sql_exp*)m->data)->r;
+ atms = append(atms, (atom*)val_exp->l);
+ }
+ mcas->gvs = sa_list(sql->sa);
+ mcas->gvs = append(mcas->gvs, atms);
+
+ hash_add(meqh, key, mcas);
+ }
+
+ /* TODO: manage the entries: remove the entry of the
ands list as we are going to reconstruct it later */
+ }
+ }
+ return multi_multivalue_cmp_eq;
+}
+
static bool
exp_or_chain_groups(mvc *sql, list *exps, list **ands, list **noneq, sql_hash
*eqh)
{
@@ -581,7 +687,7 @@ exp_or_chain_groups(mvc *sql, list *exps
static list *
merge_ors_NEW(mvc *sql, list *exps, int *changes)
{
- sql_hash *eqh = NULL;
+ sql_hash *eqh = NULL, *meqh = NULL;
list *neq, *ands, *ins;
for (node *n = exps->h; n; n = n->next) {
sql_exp *e = n->data;
@@ -625,6 +731,12 @@ merge_ors_NEW(mvc *sql, list *exps, int
}
}
+ /* detect AND-chained cmp_eq-only exps with multiple
values */
+ if (list_length(ands) > 1) {
+ meqh = hash_new(sql->sa, 4 /* TODO: HOW MUCH?
prob. 16*/, (fkeyvalue)&hash_key);
+ detect_multivalue_cmp_eqs(sql, ands, meqh);
+ }
+
/* create the new OR tree */
assert(list_length(ins));
sql_exp *new = ins->h->data;
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