Re: Improving replay of XLOG_BTREE_VACUUM records - Mailing list pgsql-hackers

25 авг. 2015 г., в 16:03, Michael Paquier <michael.paquier@gmail.com> написал(а):

On Sun, Jul 26, 2015 at 9:46 PM, Andres Freund wrote:

On 2015-07-24 09:53:49 +0300, Heikki Linnakangas wrote:
To me it sounds like this shouldn't go through the full ReadBuffer()
rigamarole. That code is already complex enough, and here it's really
not needed. I think it'll be much easier to review - and actually faster
in many cases to simply have something like

bool
BufferInCache(Relation, ForkNumber, BlockNumber)
{
   /* XXX: setup tag, hash, partition */

   LWLockAcquire(newPartitionLock, LW_SHARED);
   buf_id = BufTableLookup(&newTag, newHash);
   LWLockRelease(newPartitionLock);
   return buf_id != -1;
}

and then fall back to the normal ReadBuffer() when it's in cache.

Patch marked as returned with feedback as input from the author has
been waited for some time now.

--
Michael