Re: performance optimzations

On Wed, 2003-11-12 at 12:23, Rod Taylor wrote:
> On Wed, 2003-11-12 at 12:34, Suchandra Thapa wrote:
> > I'm moving a webmail service over to use a postgresql database for
> > storage and wanted to get any tips for optimizing performance.  The
> > machine will be a multiprocessor (either 2 or 4 cpu ) system with a raid
> > array.  What layout should be used?  I was thinking using about using a
> > raid 1+0 array to hold the database but since I can use different array
> > types, would it be better to use 1+0 for the wal logs and a raid 5 for
> > the database?
>
> How much in total storage?  If you have (or will have) > ~6 disks, go
> for RAID 5 otherwise 10 is probably appropriate.

I'm not sure but I believe there are about 6-8 10K scsi drives on the
system.   There is quite a bit of storage to spare currently so I think

> > The database gets fairly heavy activity (the system handles about 500MB
> > of incoming and about 750MB of outgoing emails daily).  I have a fairly
> > free rein in regards to the system's layout as well as how the
> > applications will interact with the database since I'm writing the
> > code.
>
> These are archived permanently -- ~450GB of annual data? Or is the data
> removed upon delivery?

No, it's more like hotmail.  Some users may keep mail for a longer term
but a lot of the mail probably gets deleted fairly quickly.  The
database load will be mixed with a insertions due to deliveries, queries
by the webmail system, and deletions from pop and webmail.

--
Suchandra Thapa <s-thapa-11@alumni.uchicago.edu>