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Scan the buffer pool just once, not once per fork, during relation drop.

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This provides a speedup of about 4X when NBuffers is large enough.
There is also a useful reduction in sinval traffic, since we
only do CacheInvalidateSmgr() once not once per fork.

Simon Riggs, reviewed and somewhat revised by Tom Lane
This commit is contained in:
Tom Lane
2012-06-07 17:42:27 -04:00
parent 5baf6da717
commit ece01aae47
9 changed files with 150 additions and 23 deletions
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40
src/backend/storage/buffer/localbuf.c
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@ -330,6 +330,46 @@ DropRelFileNodeLocalBuffers(RelFileNode rnode, ForkNumber forkNum,
}
}
/*
* DropRelFileNodeAllLocalBuffers
* This function removes from the buffer pool all pages of all forks
* of the specified relation.
*
* See DropRelFileNodeAllBuffers in bufmgr.c for more notes.
*/
void
DropRelFileNodeAllLocalBuffers(RelFileNode rnode)
{
int i;
for (i = 0; i < NLocBuffer; i++)
{
BufferDesc *bufHdr = &LocalBufferDescriptors[i];
LocalBufferLookupEnt *hresult;
if ((bufHdr->flags & BM_TAG_VALID) &&
RelFileNodeEquals(bufHdr->tag.rnode, rnode))
{
if (LocalRefCount[i] != 0)
elog(ERROR, "block %u of %s is still referenced (local %u)",
bufHdr->tag.blockNum,
relpathbackend(bufHdr->tag.rnode, MyBackendId,
bufHdr->tag.forkNum),
LocalRefCount[i]);
/* Remove entry from hashtable */
hresult = (LocalBufferLookupEnt *)
hash_search(LocalBufHash, (void *) &bufHdr->tag,
HASH_REMOVE, NULL);
if (!hresult) /* shouldn't happen */
elog(ERROR, "local buffer hash table corrupted");
/* Mark buffer invalid */
CLEAR_BUFFERTAG(bufHdr->tag);
bufHdr->flags = 0;
bufHdr->usage_count = 0;
}
}
}
/*
* InitLocalBuffers -
* init the local buffer cache. Since most queries (esp. multi-user ones)