diff options
Diffstat (limited to 'src/backend/access/hash/hashsearch.c')
| -rw-r--r-- | src/backend/access/hash/hashsearch.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/src/backend/access/hash/hashsearch.c b/src/backend/access/hash/hashsearch.c index 5582c036417..52e867e3605 100644 --- a/src/backend/access/hash/hashsearch.c +++ b/src/backend/access/hash/hashsearch.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/hash/hashsearch.c,v 1.47 2007/01/20 18:43:35 neilc Exp $ + * $PostgreSQL: pgsql/src/backend/access/hash/hashsearch.c,v 1.48 2007/01/30 01:33:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -115,6 +115,7 @@ _hash_first(IndexScanDesc scan, ScanDirection dir) { Relation rel = scan->indexRelation; HashScanOpaque so = (HashScanOpaque) scan->opaque; + ScanKey cur; uint32 hashkey; Bucket bucket; BlockNumber blkno; @@ -143,18 +144,37 @@ _hash_first(IndexScanDesc scan, ScanDirection dir) (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("hash indexes do not support whole-index scans"))); + /* There may be more than one index qual, but we hash only the first */ + cur = &scan->keyData[0]; + + /* We support only single-column hash indexes */ + Assert(cur->sk_attno == 1); + /* And there's only one operator strategy, too */ + Assert(cur->sk_strategy == HTEqualStrategyNumber); + /* * If the constant in the index qual is NULL, assume it cannot match any * items in the index. */ - if (scan->keyData[0].sk_flags & SK_ISNULL) + if (cur->sk_flags & SK_ISNULL) return false; /* * Okay to compute the hash key. We want to do this before acquiring any * locks, in case a user-defined hash function happens to be slow. + * + * If scankey operator is not a cross-type comparison, we can use the + * cached hash function; otherwise gotta look it up in the catalogs. + * + * We support the convention that sk_subtype == InvalidOid means the + * opclass input type; this is a hack to simplify life for ScanKeyInit(). */ - hashkey = _hash_datum2hashkey(rel, scan->keyData[0].sk_argument); + if (cur->sk_subtype == rel->rd_opcintype[0] || + cur->sk_subtype == InvalidOid) + hashkey = _hash_datum2hashkey(rel, cur->sk_argument); + else + hashkey = _hash_datum2hashkey_type(rel, cur->sk_argument, + cur->sk_subtype); /* * Acquire shared split lock so we can compute the target bucket safely |