Changeset: 228baed29b7e for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=228baed29b7e
Modified Files:
sql/backends/monet5/rel_bin.c
Branch: default
Log Message:
During primary key check perform subgroupby only to groups with > 1 members.
Make sure that we are not doing extra work by performing subgroupby on groups
that have onlyone member. In practice this should mean only one subgroup on the
hash values of a combined key, and a subgroup on the few collisions (if any).
This emulates a candidate list from groupby. If we ever support directly
candidate lists in the groupby operator, this code can be simplified by
avoiding the leftfetch joins.
diffs (42 lines):
diff --git a/sql/backends/monet5/rel_bin.c b/sql/backends/monet5/rel_bin.c
--- a/sql/backends/monet5/rel_bin.c
+++ b/sql/backends/monet5/rel_bin.c
@@ -3163,6 +3163,7 @@ update_check_ukey(mvc *sql, stmt **updat
sql_subaggr *sum;
stmt *count_sum = NULL, *ssum;
stmt *g = NULL, *grp = NULL, *ext = NULL, *Cnt = NULL;
+ stmt *cand = NULL;
stmt *ss;
sql_subfunc *or = sql_bind_func_result(sql->sa,
sql->session->schema, "or", bt, bt, bt);
@@ -3173,7 +3174,20 @@ update_check_ukey(mvc *sql, stmt **updat
grp = stmt_result(sql->sa, g, 0);
ext = stmt_result(sql->sa, g, 1);
Cnt = stmt_result(sql->sa, g, 2);
+
+ /* choose only groups with cnt > 1 */
+ cand = stmt_uselect(sql->sa, Cnt,
stmt_atom_wrd(sql->sa, 1), cmp_gt, NULL);
+ /* project cand on ext and Cnt */
+ Cnt = stmt_project(sql->sa, cand, Cnt);
+ ext = stmt_project(sql->sa, cand, ext);
+
+ /* join ext with group to retrieve all oid's of
the original
+ * bat that belong to a group with Cnt >1 */
+ g = stmt_join(sql->sa, ext, grp, cmp_equal);
+ cand = stmt_result(sql->sa, g, 1);
+ grp = stmt_project(sql->sa, cand, grp);
}
+
for (m = k->columns->h; m; m = m->next) {
sql_kc *c = m->data;
stmt *upd;
@@ -3194,6 +3208,9 @@ update_check_ukey(mvc *sql, stmt **updat
grp =
stmt_reorder_project(sql->sa, nn, grp);
}
+ /* apply cand list first */
+ upd = stmt_project(sql->sa, cand, upd);
+ /* apply group by on groups with Cnt > 1 */
g = stmt_group(sql->sa, upd, grp, ext, Cnt);
grp = stmt_result(sql->sa, g, 0);
ext = stmt_result(sql->sa, g, 1);
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