On Mon, Nov 26, 2012 at 3:29 PM, Jeff Davis <[email protected]> wrote: > Your intuition here is better than mine, but I am still missing > something here. If we keep the buffer pinned, then there will be very > few pin/unpin cycles here, so I don't see where the contention would > come from (any more than there is contention pinning the root of an > index).
Based on previous measurements, I think there *is* contention pinning the root of an index. Currently, I believe it's largely overwhelmed by contention from other sources, such as the buffer manager lwlocks and the very-evil ProcArrayLock. However, I believe that as we fix those problems, this will start to percolate up towards the top of the heap. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
