Re: Sorting performance vs. MySQL

On Mon, Feb 22, 2010 at 12:53 PM, Yang Zhang <yanghatespam@gmail.com> wrote:
> On Mon, Feb 22, 2010 at 2:52 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
>> On Mon, Feb 22, 2010 at 11:10 AM, Yang Zhang <yanghatespam@gmail.com> wrote:
>>> I have the exact same table of data in both MySQL and Postgresql. In Postgresql:
>>
>> Just wondering, are these on the same exact machine?
>>
>
> Yes, on the same disk.

I'm wondering how much of this could be caching effects.  Is the MySQL
database "warmed up" before you started, and the pgsql database is
"cold" and no caching has taken place?

What do things like vmstat 10 say while the query is running on each
db?  First time, second time, things like that.

Also, just curios, what's shared_buffers set to on the pgsql instance?