Re: two disks - best way to use them?

From: Ron <rjpeace(at)earthlink(dot)net>
To: "Rick Schumeyer" <rschumeyer(at)ieee(dot)org>, <pgsql-performance(at)postgresql(dot)org>
Subject: Re: two disks - best way to use them?
Date: 2005-12-02 20:05:30
Message-ID: 6.2.5.6.0.20051202145746.01dc7b68@earthlink.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

At 01:58 PM 12/2/2005, Rick Schumeyer wrote:
>I installed another drive in my linux pc in an attempt to improve performance
>on a large COPY to a table with a geometry index.
>
>Based on previous discussion, it seems there are three things
>competing for the hard drive:
>
>1) the input data file
>2) the pg table
>3) the WAL
>
>What is the best way to distribute these among two drives? From
>Tom's comments
>I would think that the pg table and the WAL should be
>separate. Does it matter where the input data is?

Best is to have 3 HD or HD sets, one for each of the above.

With only 2, and assuming the input file is too large to fit
completely into RAM at once, I'd test to see whether:
a= input on one + pg table & WAL on the other, or
b= WAL on one + pg table & input file on the other
is best.

If the input file can be made 100% RAM resident, then use
c= pg table on one + WAL and input file on the other.

The big goal here is to minimize HD head seeks.

Ron

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Stephen Frost 2005-12-02 20:18:47 Re: Database restore speed
Previous Message Rick Schumeyer 2005-12-02 18:58:13 two disks - best way to use them?