Changeset: 75799399a5bf for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=75799399a5bf
Modified Files:
gdk/gdk_join.c
Branch: default
Log Message:
Reduce number of tests; add comments.
diffs (47 lines):
diff --git a/gdk/gdk_join.c b/gdk/gdk_join.c
--- a/gdk/gdk_join.c
+++ b/gdk/gdk_join.c
@@ -358,17 +358,40 @@ mergejoin(BAT *r1, BAT *r2, BAT *l, BAT
}
/* maintain properties */
- if (nl > 1)
+ if (nl > 1) {
+ /* value occurs multiple times in l, so entry
+ * in r will be repeated multiple times: hence
+ * r2 is not key */
r2->tkey = 0;
- if (nl > 1 || BATcount(r1) > 0)
+ /* multiple different values will be inserted
+ * in r1 (always in order), so not reverse
+ * ordered anymore */
r1->trevsorted = 0;
+ }
if (nr > 1) {
+ /* value occurs multiple times in r, so entry
+ * in l will be repeated multiple times: hence
+ * r1 is not key */
r1->tkey = 0;
+ /* multiple different values will be inserted
+ * in r2 (in order), so not reverse ordered
+ * anymore */
r2->trevsorted = 0;
- if (nl > 1)
+ if (nl > 1) {
+ /* multiple values in l match multiple
+ * values in r, so an ordered sequence
+ * will be inserted multiple times in
+ * r2, so r2 is not ordered anymore */
r2->tsorted = 0;
+ }
}
if (BATcount(r1) > 0) {
+ /* a new, higher value will be inserted into
+ * r1, so r1 is not reverse ordered anymore */
+ r1->trevsorted = 0;
+ /* depending on whether l and r are ordered
+ * the same or not, a new higher or lower
+ * value will be added to r2 */
if (equal_order)
r2->trevsorted = 0;
else
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