Re: Raw size

> BUT after clustering triples according to an index on att1:
> 
> 
> 
> select relname, relpages from pg_class ;
>              relname             | relpages
> ---------------------------------+----------
>  triples                         |      142  (8KB/buffer)
> 
> 142 * 8 * 1024 = 1,163,264 Bytes
> 
> 
> Is there any compression or what?

Yes, there is:

http://www.postgresql.org/docs/8.0/interactive/storage-toast.html

Chris