On Thu, May 7, 2009 at 10:52 PM, <david@xxxxxxx> wrote: >>> Hopefully, notions of partitioning won't be directly tied to chunking of >>> data for parallel query access. Most queries access recent data and >>> hence only a single partition (or stripe), so partitioning and >>> parallelism and frequently exactly orthogonal. >> >> Yes, I think those things are unrelated. > > I'm not so sure (warning, I am relativly inexperianced in this area) > > it sounds like you can take two basic approaches to partition a database > > 1. The Isolation Plan [...] > 2. The Load Balancing Plan Well, even if the table is not partitioned at all, I don't see that it should preclude parallel query access. If I've got a 1 GB table that needs to be sequentially scanned for rows meeting some restriction clause, and I have two CPUs and plenty of I/O bandwidth, ISTM it should be possible to have them each scan half of the table and combine the results. Now, this is not easy and there are probably substantial planner and executor changes required to make it work, but I don't know that it would be particularly easier if I had two 500 MB partitions instead of a single 1 GB table. IOW, I don't think you should need to partition if all you want is load balancing. Partitioning should be for isolation, and load balancing should happen when appropriate, whether there is partitioning involved or not. ...Robert -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
