I am working with an application whose performance is limited by the write
activity (inserts, updates and deletes) on three specific tables. The
database is RAM resident so read performance is not limited by the disk
speeds.

We are using Postgres 8 and I am wondering about the best way to set up
tablespaces. We have 3 disk arrays. Would it make more sense to place each
of tables 1,2 and 3 and their associated indexes on their own dedicated
array or would it be better to split each table and it's indexes across the
arrays? The activity pattern for the three tables is as follows

Table 1: Lots of inserts, updates and deletes. A lot of indexes and
searches.

Tables 2 and 3: Lots of updates, searches and indexes. Not too many inserts
or deletes.

Any insight would be appreciated.

Emil