MonetDB: cmp-or-patterns - Replaces multi col hash key with simp...

[stefanos mavros via checkin-list]

Changeset: 5ee42fc29614 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/5ee42fc29614
Modified Files:
        sql/server/rel_optimize_sel.c
Branch: cmp-or-patterns
Log Message:

Replaces multi col hash key with simpler function


diffs (52 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
@@ -524,6 +524,17 @@ exp_cmp_eq_unique_id(sql_exp *e)
        return exp_unique_id(e->l);
 }
 
+static inline int
+exp_multi_col_key(list *l)
+{
+       int k = exp_unique_id(l->h->data);
+       for (node *n = l->h->next; n; n = n->next) {
+               k <<= 4;
+               k ^= exp_unique_id(n->data);
+       }
+       return k;
+}
+
 typedef struct exp_eq_col_values {
        /* we need ->first in order to remove it from the list of cmp_eq exps
         * in case that we find another occurrence (with a different value)
@@ -605,20 +616,10 @@ detect_multicol_cmp_eqs(mvc *sql, list *
                list_append_before(mce_ands, n, sl);
                list_remove_node(mce_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;
-                       if (col_exp->alias.rname)
-                               cs = strconcat(cs, 
strconcat(col_exp->alias.rname, col_exp->alias.name));
-                       else
-                               cs = strconcat(cs, col_exp->alias.name);
-               }
-
                /* find the eq exp in the hash and append the values */
                bool found = false;
 
-               int key = meqh->key(cs);
+               int key = meqh->key(sl);
                sql_hash_e *he = meqh->buckets[key&(meqh->size-1)];
 
                for (;he && !found; he = he->chain) {
@@ -794,7 +795,7 @@ merge_ors_NEW(mvc *sql, list *exps, int 
                        /* detect mutli-col cmp_eq exps with multiple (lists 
of) values */
                        bool multicol_multival = false;
                        if (list_length(mce_ands) > 1) {
-                               meqh = hash_new(sql->sa, 4 /* TODO: HOW MUCH? 
prob. 16*/, (fkeyvalue)&hash_key);
+                               meqh = hash_new(sql->sa, 4 /* TODO: HOW MUCH? 
prob. 16*/, (fkeyvalue)&exp_multi_col_key);
                                multicol_multival = 
detect_multicol_cmp_eqs(sql, mce_ands, meqh);
                        }
 
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