Re: partition query on multiple cores

On Tue, May 10, 2011 at 12:22 PM, Shaun Thomas <sthomas(at)peak6(dot)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.

Mason