Обсуждение: Multi-processors

>>> "c k" <shreeseva.learning@gmail.com> wrote:

> Does PG uses multiple processors/cores if available by default on
various
> OSes?

A separate process is created to handle each connection.  You don't
get much benefit from multiple processors if only one connection at a
time is running a query, but in a normal mix it uses all processors.

> What are the limitations on using multiple processors/cores and main
> memory?

I'm not sure what you're getting at here, but PostgreSQL goes through
the file system, so OS caching (which is what usually happens to
otherwise unused system RAM) benefits PostgreSQL.  Does that help?

-Kevin

On Fri, Sep 19, 2008 at 5:55 AM, c k <shreeseva.learning@gmail.com> wrote:
> Hello PG Community,
> Does PG uses multiple processors/cores if available by default on various
> OSes?

Yes, see attached top extract from my primary db server at work

> What are the limitations on using multiple processors/cores and main
> memory?

Do you mean how many CPUs and how much memory?  no real limits on a 64
bit machine. Note that it's often better to let the os do the majority
of caching, depending on your work load.  This is especially true in
OLTP where the cost of pgsql maintaining a large buffer is higher than
the benefit it provides, but the kernel can cache much larger datasets
faster, in my experience.