Controlling Table/Index Location

I am aware of the initlocation command that allows me to set up a new
directory location for a database

CREATE DATABASE xxx WITH LOCATION = 'xxx';

I am interested a finer level of control for performance reasons.
Specifying that this table belongs on this disk pack whiles it corresponding
index belongs on this disk pack may be useful for performance tuning.

CREATE TABLE xxx ....
WITH LOCATION =

CREATE INDEX xxx ...
WITH LOCATION =

I though maybe I could do it using the File System Links but the data
directories seem to be grouped in the numbers that do not correspond to the
oid from the pg_types table...

Any Idease on this one are appreciated.

Jeff Young