On Tue, May 10, 2011 at 12:22 PM, Shaun Thomas <sthomas@peak6.com> wrote:
On 05/10/2011 10:06 AM, Maciek Sakrejda wrote:
I have 8-core server, I wanted to ask whether a query can be divided for multiple processors or cores, if it could be what to do in postgresql
No, at this time (and for the foreseeable future), a single query will run on a single core.
It can *kinda* be done. Take a look at GridSQL. It's really good for splitting up reporting-like queries that benefit from parallel access of large tables. It's not exactly Hadoop, but I ran a test on a single system with two separate instances of PostgreSQL, and a single query over those two nodes cut execution time in half.
It's meant for server parallelism, so I wouldn't necessarily recommend splitting your data up across nodes on the same server. But it seems to deliver as promised when used in the right circumstances.
Yes, GridSQL is useful even in multi-core scenarios on a single server for query parallelism. You can also use the same PostgreSQL instance (cluster), as the virtual node databases are named distinctly, which simplifies configuration.