Re: strange performance regression between 7.4 and 8.1

On 02.03.2007, at 14:20, Alex Deucher wrote:

> Ah OK.  I see what you are saying;  thank you for clarifying.  Yes,
> the SAN is configured for maximum capacity; it has large RAID 5
> groups.  As I said earlier, we never intended to run a DB on the SAN,
> it just happened to come up, hence the configuration.

So why not dumping the stuff ones, importing into a PG configured to  
use local discs (Or even ONE local disc, you might have the 16GB you  
gave as a size for the db on the local machine, right?) and testing  
whether the problem is with PG connecting to the SAN. So you have one  
factor less to consider after all your changes.

Maybe it's just that something in the chain from PG to the actual HD  
spindles kills your random access performance for getting the actual  
rows.

cug