diff options
Diffstat (limited to 'src/backend/storage')
| -rw-r--r-- | src/backend/storage/smgr/md.c | 5 | ||||
| -rw-r--r-- | src/backend/storage/smgr/smgr.c | 9 |
2 files changed, 11 insertions, 3 deletions
diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c index 1c0cb7e240b..fa7913aff74 100644 --- a/src/backend/storage/smgr/md.c +++ b/src/backend/storage/smgr/md.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.115 2005/05/29 04:23:05 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.116 2005/06/20 18:37:01 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -660,6 +660,9 @@ mdtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp) /* * mdimmedsync() -- Immediately sync a relation to stable storage. + * + * Note that only writes already issued are synced; this routine knows + * nothing of dirty buffers that may exist inside the buffer manager. */ bool mdimmedsync(SMgrRelation reln) diff --git a/src/backend/storage/smgr/smgr.c b/src/backend/storage/smgr/smgr.c index 2c8cf07eec8..f286b20ee25 100644 --- a/src/backend/storage/smgr/smgr.c +++ b/src/backend/storage/smgr/smgr.c @@ -11,7 +11,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.90 2005/06/17 22:32:46 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.91 2005/06/20 18:37:01 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -650,7 +650,8 @@ smgrtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp) /* * smgrimmedsync() -- Force the specified relation to stable storage. * - * Synchronously force all of the specified relation down to disk. + * Synchronously force all previous writes to the specified relation + * down to disk. * * This is useful for building completely new relations (eg, new * indexes). Instead of incrementally WAL-logging the index build @@ -664,6 +665,10 @@ smgrtruncate(SMgrRelation reln, BlockNumber nblocks, bool isTemp) * * The preceding writes should specify isTemp = true to avoid * duplicative fsyncs. + * + * Note that you need to do FlushRelationBuffers() first if there is + * any possibility that there are dirty buffers for the relation; + * otherwise the sync is not very meaningful. */ void smgrimmedsync(SMgrRelation reln) |