diff options
Diffstat (limited to 'src/backend/access/hash/hash.c')
| -rw-r--r-- | src/backend/access/hash/hash.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c index 41607c54dc3..af4c4c058fd 100644 --- a/src/backend/access/hash/hash.c +++ b/src/backend/access/hash/hash.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/hash/hash.c,v 1.104 2008/06/19 00:46:03 alvherre Exp $ + * $PostgreSQL: pgsql/src/backend/access/hash/hash.c,v 1.105 2008/09/15 18:43:41 tgl Exp $ * * NOTES * This file contains only the public interface routines. @@ -79,12 +79,12 @@ hashbuild(PG_FUNCTION_ARGS) * then we'll thrash horribly. To prevent that scenario, we can sort the * tuples by (expected) bucket number. However, such a sort is useless * overhead when the index does fit in RAM. We choose to sort if the - * initial index size exceeds effective_cache_size. + * initial index size exceeds NBuffers. * * NOTE: this test will need adjustment if a bucket is ever different * from one page. */ - if (num_buckets >= (uint32) effective_cache_size) + if (num_buckets >= (uint32) NBuffers) buildstate.spool = _h_spoolinit(index, num_buckets); else buildstate.spool = NULL; @@ -129,7 +129,7 @@ hashbuildCallback(Relation index, IndexTuple itup; /* form an index tuple and point it at the heap tuple */ - itup = index_form_tuple(RelationGetDescr(index), values, isnull); + itup = _hash_form_tuple(index, values, isnull); itup->t_tid = htup->t_self; /* Hash indexes don't index nulls, see notes in hashinsert */ @@ -153,8 +153,8 @@ hashbuildCallback(Relation index, /* * hashinsert() -- insert an index tuple into a hash table. * - * Hash on the index tuple's key, find the appropriate location - * for the new tuple, and put it there. + * Hash on the heap tuple's key, form an index tuple with hash code. + * Find the appropriate location for the new tuple, and put it there. */ Datum hashinsert(PG_FUNCTION_ARGS) @@ -171,7 +171,7 @@ hashinsert(PG_FUNCTION_ARGS) IndexTuple itup; /* generate an index tuple */ - itup = index_form_tuple(RelationGetDescr(rel), values, isnull); + itup = _hash_form_tuple(rel, values, isnull); itup->t_tid = *ht_ctid; /* @@ -211,8 +211,8 @@ hashgettuple(PG_FUNCTION_ARGS) OffsetNumber offnum; bool res; - /* Hash indexes are never lossy (at the moment anyway) */ - scan->xs_recheck = false; + /* Hash indexes are always lossy since we store only the hash code */ + scan->xs_recheck = true; /* * We hold pin but not lock on current buffer while outside the hash AM. @@ -317,7 +317,8 @@ hashgetbitmap(PG_FUNCTION_ARGS) /* Save tuple ID, and continue scanning */ if (add_tuple) { - tbm_add_tuples(tbm, &scan->xs_ctup.t_self, 1, false); + /* Note we mark the tuple ID as requiring recheck */ + tbm_add_tuples(tbm, &scan->xs_ctup.t_self, 1, true); ntids++; } @@ -527,7 +528,7 @@ hashbulkdelete(PG_FUNCTION_ARGS) * each bucket. */ metabuf = _hash_getbuf(rel, HASH_METAPAGE, HASH_READ, LH_META_PAGE); - metap = (HashMetaPage) BufferGetPage(metabuf); + metap = HashPageGetMeta(BufferGetPage(metabuf)); orig_maxbucket = metap->hashm_maxbucket; orig_ntuples = metap->hashm_ntuples; memcpy(&local_metapage, metap, sizeof(local_metapage)); @@ -629,7 +630,7 @@ loop_top: /* Write-lock metapage and check for split since we started */ metabuf = _hash_getbuf(rel, HASH_METAPAGE, HASH_WRITE, LH_META_PAGE); - metap = (HashMetaPage) BufferGetPage(metabuf); + metap = HashPageGetMeta(BufferGetPage(metabuf)); if (cur_maxbucket != metap->hashm_maxbucket) { |