Changeset: 81c2f901aee4 for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=81c2f901aee4
Modified Files:
gdk/gdk_join.c
Branch: linear-hashing
Log Message:
Make more use of candidate iterators.
diffs (130 lines):
diff --git a/gdk/gdk_join.c b/gdk/gdk_join.c
--- a/gdk/gdk_join.c
+++ b/gdk/gdk_join.c
@@ -2407,7 +2407,7 @@ mergejoin(BAT **r1p, BAT **r2p, BAT *l,
/* no match */ \
if (not_in) \
continue; \
- } else if (sr) { \
+ } else if (hash_cand) { \
for (rb = HASHget(hsh, hash_##TYPE(hsh, &v)); \
rb != HASHnil(hsh); \
rb = HASHgetlink(hsh, rb)) { \
@@ -2498,6 +2498,7 @@ hashjoin(BAT **r1p, BAT **r2p, BAT *l, B
const char *v = (const char *) &lval;
bool lskipped = false; /* whether we skipped values in l */
Hash *restrict hsh;
+ bool hash_cand = false;
assert(!BATtvoid(r));
assert(ATOMtype(l->ttype) == ATOMtype(r->ttype));
@@ -2547,42 +2548,53 @@ hashjoin(BAT **r1p, BAT **r2p, BAT *l, B
r = b;
}
- if (sr) {
- if (BATtdense(sr) &&
- BATcheckhash(r) &&
+ hsh = NULL;
+ if (rci->tpe == cand_dense) {
+ if (BATcheckhash(r) &&
BATcount(r) / r->thash->nheads * lci->ncand < lci->ncand +
rci->ncand) {
+ /* there is a hash already and the collision
+ * chains aren't too long, use it */
ALGODEBUG fprintf(stderr, "#%s: %s(%s): using "
"existing hash with candidate list\n",
MT_thread_getname(), __func__,
BATgetId(r));
hsh = r->thash;
- sr = NULL;
- } else {
- char ext[32];
- assert(!phash);
- ALGODEBUG fprintf(stderr, "#%s: %s(%s): creating "
- "hash for candidate list\n",
- MT_thread_getname(), __func__,
- BATgetId(r));
- if (snprintf(ext, sizeof(ext), "thshjn%x",
sr->batCacheid) >= (int) sizeof(ext))
- goto bailout;
- if ((hsh = BAThash_impl(r, sr, ext)) == NULL) {
+ } else if (rci->ncand == BATcount(r) ||
+ (!r->batTransient &&
+ rci->ncand > BATcount(r) * 4 / 5)) {
+ /* if there is (effectively) no candidate
+ * list, or if b is persistent and we're
+ * joining with the majority of b, create a
+ * hash on b */
+ if (BAThash(r) != GDK_SUCCEED) {
+ hsh = NULL;
goto bailout;
}
+ hsh = r->thash;
}
- } else {
- if (BAThash(r) != GDK_SUCCEED) {
- hsh = NULL;
+ }
+ if (hsh == NULL) {
+ /* create a hash for the part of b that is candidate */
+ char ext[32];
+ assert(!phash);
+ assert(sr != NULL);
+ ALGODEBUG fprintf(stderr, "#%s: %s(%s): creating "
+ "hash for candidate list\n",
+ MT_thread_getname(), __func__,
+ BATgetId(r));
+ if (snprintf(ext, sizeof(ext), "thshjn%x", sr->batCacheid) >=
(int) sizeof(ext))
+ goto bailout;
+ if ((hsh = BAThash_impl(r, sr, ext)) == NULL) {
goto bailout;
}
- hsh = r->thash;
+ hash_cand = true;
}
ri = bat_iterator(r);
if (not_in && !r->tnonil) {
/* check whether there is a nil on the right, since if
* so, we should return an empty result */
- if (sr) {
+ if (hash_cand) {
for (rb = HASHget(hsh, HASHprobe(hsh, nil));
rb != HASHnil(hsh);
rb = HASHgetlink(hsh, rb)) {
@@ -2639,7 +2651,7 @@ hashjoin(BAT **r1p, BAT **r2p, BAT *l, B
/* no match */
if (not_in)
continue;
- } else if (sr) {
+ } else if (hash_cand) {
for (rb = HASHget(hsh, HASHprobe(hsh, v));
rb != HASHnil(hsh);
rb = HASHgetlink(hsh, rb)) {
@@ -2706,7 +2718,7 @@ hashjoin(BAT **r1p, BAT **r2p, BAT *l, B
}
break;
}
- if (sr) {
+ if (hash_cand) {
HEAPfree(&hsh->heaplink, true);
HEAPfree(&hsh->heapbckt, true);
GDKfree(hsh);
@@ -2757,7 +2769,7 @@ hashjoin(BAT **r1p, BAT **r2p, BAT *l, B
return GDK_SUCCEED;
bailout:
- if (sr && hsh) {
+ if (hash_cand && hsh) {
HEAPfree(&hsh->heaplink, true);
HEAPfree(&hsh->heapbckt, true);
GDKfree(hsh);
@@ -3478,7 +3490,8 @@ leftjoin(BAT **r1p, BAT **r2p, BAT *l, B
nil_matches, nil_on_miss, semi, only_misses,
not_in, estimate, t0, false, func);
}
- phash = sr == NULL &&
+ phash = rci.tpe == cand_dense &&
+ rci.ncand == BATcount(r) &&
VIEWtparent(r) != 0 &&
BATcount(BBP_cache(VIEWtparent(r))) == BATcount(r);
return hashjoin(r1p, r2p, l, r, sl, sr, &lci, &rci,
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