Changeset: f14ce2b0f47c for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=f14ce2b0f47c
Modified Files:
gdk/gdk_select.c
Branch: Oct2012
Log Message:
make sure we go for hash select in case of very high selectivity (ie sample
returns 0 selected)
diffs (13 lines):
diff --git a/gdk/gdk_select.c b/gdk/gdk_select.c
--- a/gdk/gdk_select.c
+++ b/gdk/gdk_select.c
@@ -932,6 +932,9 @@ BATsubselect(BAT *b, BAT *s, const void
/* linear extrapolation plus 10% margin */
estimate = (BUN) ((dbl) slct_cnt / (dbl)
smpl_cnt
* (dbl) BATcount(b) * 1.1);
+ } else if (smpl_cnt > 0 && slct_cnt == 0) {
+ /* estimate low enough to trigger hash select */
+ estimate = (BATcount(b)/100) -1;
}
}
hash = hash && estimate < BATcount(b) / 100;
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