diff options
Diffstat (limited to 'src/backend/access/hash/hashpage.c')
| -rw-r--r-- | src/backend/access/hash/hashpage.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/src/backend/access/hash/hashpage.c b/src/backend/access/hash/hashpage.c index ec6f4b390f..d179af0121 100644 --- a/src/backend/access/hash/hashpage.c +++ b/src/backend/access/hash/hashpage.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/access/hash/hashpage.c,v 1.73 2008/03/15 20:46:31 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/access/hash/hashpage.c,v 1.74 2008/03/16 23:15:08 tgl Exp $ * * NOTES * Postgres hash pages look like ordinary relation pages. The opaque @@ -315,13 +315,14 @@ _hash_chgbufaccess(Relation rel, * the initial buckets, and the initial bitmap page. * * The initial number of buckets is dependent on num_tuples, an estimate - * of the number of tuples to be loaded into the index initially. + * of the number of tuples to be loaded into the index initially. The + * chosen number of buckets is returned. * * We are fairly cavalier about locking here, since we know that no one else * could be accessing this index. In particular the rule about not holding * multiple buffer locks is ignored. */ -void +uint32 _hash_metapinit(Relation rel, double num_tuples) { HashMetaPage metap; @@ -438,10 +439,21 @@ _hash_metapinit(Relation rel, double num_tuples) metap->hashm_firstfree = 0; /* + * Release buffer lock on the metapage while we initialize buckets. + * Otherwise, we'll be in interrupt holdoff and the CHECK_FOR_INTERRUPTS + * won't accomplish anything. It's a bad idea to hold buffer locks + * for long intervals in any case, since that can block the bgwriter. + */ + _hash_chgbufaccess(rel, metabuf, HASH_WRITE, HASH_NOLOCK); + + /* * Initialize the first N buckets */ for (i = 0; i < num_buckets; i++) { + /* Allow interrupts, in case N is huge */ + CHECK_FOR_INTERRUPTS(); + buf = _hash_getnewbuf(rel, BUCKET_TO_BLKNO(metap, i)); pg = BufferGetPage(buf); pageopaque = (HashPageOpaque) PageGetSpecialPointer(pg); @@ -453,6 +465,9 @@ _hash_metapinit(Relation rel, double num_tuples) _hash_wrtbuf(rel, buf); } + /* Now reacquire buffer lock on metapage */ + _hash_chgbufaccess(rel, metabuf, HASH_NOLOCK, HASH_WRITE); + /* * Initialize first bitmap page */ @@ -460,6 +475,8 @@ _hash_metapinit(Relation rel, double num_tuples) /* all done */ _hash_wrtbuf(rel, metabuf); + + return num_buckets; } /* |