CLUSTER

I have a table that II am constantly inserting into (around 10 times a 
second right now but hope to increase latter).  I hold these rows for a 
week then summarize and delete them.  During that week I need to access 
ranges of these rows based on a timestamp in each row set to now() when I 
insert them.  I have this column indexed but if I let the system run after 
a few weeks it can take a fairly long time to get information from this 
table (for instance the avg() of inserted values in the last 5 minuets 
could take over a minuet to calculate).  If I run CLUSTER on the index of 
the time stamps my time to do this drops down to under 5 seconds again.  I 
checked the plan being used by explain analyze and orginally it was always 
doing seqscans so I set enable_seqscan = FALSE just before I run this 
query, this forces it to use the index and speeds it up quite a bit.

Does anyone know a way I can reorder the database without doing a 
CLUSTER?  It stops all insertions into the table and takes several minuets 
during which time a large backlog builds up.  Or should I be using some 
other method of speeding up the table?

--- Adam Kavan
--- akavan@cox.net