Re: General performance questions about postgres on Apple

On Sun, 22 Feb 2004, Sean Shanny wrote:

> Tom,
> 
> We have the following setting for random page cost:
> 
> random_page_cost = 1            # units are one sequential page fetch cost
> 
> Any suggestions on what to bump it up to?
> 
> We are waiting to hear back from Apple on the speed issues, so far we 
> are not impressed with the hardware in helping in the IO department.  
> Our DB is about 263GB with indexes now so there is not way it is going 
> to fit into memory. :-(  I have taken the step of breaking out the data 
> into month based groups just to keep the table sizes down.  Our current 
> months table has around 72 million rows in it as of today.  The joys of 
> building a data warehouse and trying to make it as fast as possible.

You may be able to achieve similar benefits with a clustered index.

see cluster:

\h cluster
Command:     CLUSTER
Description: cluster a table according to an index
Syntax:
CLUSTER indexname ON tablename
CLUSTER tablename
CLUSTER

I've found this can greatly increase speed, but on 263 gigs of data, I'd 
run it when you had a couple days free.  You might wanna test it on a 
smaller test set you can afford to chew up some I/O CPU time on over a 
weekend.