Changeset: b8e32af217ac for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=b8e32af217ac
Modified Files:
gdk/gdk_join.c
Branch: default
Log Message:
Share string heap when we can in BATproject of a string BAT.
This reduces the time query 14 op TPC-H takes somewhat.
diffs (24 lines):
diff --git a/gdk/gdk_join.c b/gdk/gdk_join.c
--- a/gdk/gdk_join.c
+++ b/gdk/gdk_join.c
@@ -3279,10 +3279,17 @@ BATproject(BAT *l, BAT *r)
}
assert(l->ttype == TYPE_oid);
- if (ATOMstorage(tpe) == TYPE_str && l->T->nonil &&
- (rcount == 0 || lcount > (rcount >> 3))) {
+ if (ATOMstorage(tpe) == TYPE_str &&
+ l->T->nonil &&
+ (rcount == 0 ||
+ lcount > (rcount >> 3) ||
+ r->batRestricted == BAT_READ)) {
/* insert strings as ints, we need to copy the string
- * heap whole sale */
+ * heap whole sale; we can not do this if there are
+ * nils in the left column, and we will not do it if
+ * the left is much smaller than the right and the
+ * right is writable (meaning we have to actually copy
+ * the right string heap) */
tpe = r->T->width == 1 ? TYPE_bte : (r->T->width == 2 ?
TYPE_sht : (r->T->width == 4 ? TYPE_int : TYPE_lng));
/* int's nil representation is a valid offset, so
* don't check for nils */
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