Changeset: 08fb275e6415 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=08fb275e6415
Modified Files:
gdk/gdk_bat.c
Branch: default
Log Message:
Skip nil/nonil property derivation in BATderive(Head)Props.
diffs (127 lines):
diff --git a/gdk/gdk_bat.c b/gdk/gdk_bat.c
--- a/gdk/gdk_bat.c
+++ b/gdk/gdk_bat.c
@@ -3053,8 +3053,12 @@ BATassertProps(BAT *b)
}
/* derive properties that can be derived with a simple scan: sorted,
- * revsorted, nil, nonil, dense; if expensive is set, we also check
- * the key property */
+ * revsorted, dense; if expensive is set, we also check the key
+ * property
+ * note that we don't check nil/nonil: we usually know pretty quickly
+ * that a column is not sorted, but we usually need a full scan for
+ * nonil.
+ */
void
BATderiveHeadProps(BAT *b, int expensive)
{
@@ -3063,7 +3067,7 @@ BATderiveHeadProps(BAT *b, int expensive
int (*cmpf)(const void *, const void *);
int cmp;
const void *prev = NULL, *valp, *nilp;
- int sorted, revsorted, key, dense, nonil;
+ int sorted, revsorted, key, dense;
const char *nme = NULL;
char *ext = NULL;
size_t nmelen;
@@ -3096,7 +3100,7 @@ BATderiveHeadProps(BAT *b, int expensive
return;
}
/* tentatively set until proven otherwise */
- key = nonil = 1;
+ key = 1;
sorted = revsorted = (BATatoms[b->htype].linear != 0);
dense = (b->htype == TYPE_oid);
BATaccessBegin(b, USE_HEAD, MMAP_SEQUENTIAL);
@@ -3180,44 +3184,51 @@ BATderiveHeadProps(BAT *b, int expensive
revsorted = 0;
if (b->H->norevsorted == 0)
b->H->norevsorted = p;
- } else if (cmp > 0) {
- sorted = 0;
- if (b->H->nosorted == 0)
- b->H->nosorted = p;
+ if (dense &&
+ * (oid *) prev + 1 != * (oid *) valp) {
+ dense = 0;
+ if (b->H->nodense == 0)
+ b->H->nodense = p;
+ }
} else {
- key = 0;
- if (b->H->nokey[0] == 0 &&
- b->H->nokey[1] == 0) {
- b->H->nokey[0] = p - 1;
- b->H->nokey[1] = p;
+ if (cmp > 0) {
+ sorted = 0;
+ if (b->H->nosorted == 0)
+ b->H->nosorted = p;
+ } else {
+ key = 0;
+ if (b->H->nokey[0] == 0 &&
+ b->H->nokey[1] == 0) {
+ b->H->nokey[0] = p - 1;
+ b->H->nokey[1] = p;
+ }
}
- }
- if (dense && * (oid *) prev + 1 != * (oid *) valp) {
- dense = 0;
- if (b->H->nodense == 0)
- b->H->nodense = p;
+ if (dense) {
+ dense = 0;
+ if (b->H->nodense == 0)
+ b->H->nodense = p;
+ }
}
} else if (dense && (sqbs = * (oid *) valp) == oid_nil) {
dense = 0;
b->H->nodense = p;
}
prev = valp;
- if (nonil && cmpf(valp, nilp) == 0)
- nonil = 0;
if (key && hs) {
prb = HASHprobe(hs, valp);
for (hb = hs->hash[prb];
hb != BUN_NONE;
- hb = hs->link[hb])
+ hb = hs->link[hb]) {
if (cmpf(valp, BUNhead(bi, hb)) == 0) {
key = 0;
b->H->nokey[0] = hb;
b->H->nokey[1] = p;
}
+ }
hs->link[p] = hs->hash[prb];
hs->hash[prb] = p;
}
- if (!sorted && !revsorted && !nonil && !(key && hs))
+ if (!sorted && !revsorted && !(key && hs))
break;
}
BATaccessEnd(b, USE_HEAD, MMAP_SEQUENTIAL);
@@ -3242,8 +3253,18 @@ BATderiveHeadProps(BAT *b, int expensive
* column is sorted */
b->hkey = key & (sorted | revsorted);
}
- b->H->nonil = nonil;
- b->H->nil = !nonil;
+ if (sorted || revsorted) {
+ /* if sorted, we only need to check the extremes to
+ * know whether there are any nils */
+ if (cmpf(BUNhead(bi, BUNfirst(b)), nilp) != 0 &&
+ cmpf(BUNhead(bi, BUNlast(b) - 1), nilp) != 0) {
+ b->H->nonil = 1;
+ b->H->nil = 0;
+ } else {
+ b->H->nonil = 0;
+ b->H->nil = 1;
+ }
+ }
#ifndef NDEBUG
BATassertHeadProps(b);
#endif
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