Fastest way to get max tstamp

This is my table:
name | program | effective | tstamp | rate
------+---------+------------+----------------------------+------
jdoe | AAA | 2006-07-01 | 2006-07-16 23:42:13.809214 | 20
jdoe | BBB | 2006-07-01 | 2006-07-16 23:42:13.809214 | 20
jdoe | AAA | 2006-08-16 | 2006-08-25 11:56:50.380575 | 20
jdoe | BBB | 2006-08-16 | 2006-08-25 11:56:50.380575 | 20
jdoe | AAA | 2006-08-16 | 2006-08-25 11:57:17.394854 | 20
jdoe | BBB | 2006-08-16 | 2006-08-25 11:57:17.394854 | 20
jdoe | AAA | 2006-09-01 | 2006-08-28 12:38:42.486513 | 20
jdoe | BBB | 2006-09-01 | 2006-08-28 12:38:42.486513 | 20

I want to get:
name | program | effective | tstamp | rate
------+---------+------------+----------------------------+------
jdoe | AAA | 2006-07-01 | 2006-07-16 23:42:13.809214 | 20
jdoe | BBB | 2006-07-01 | 2006-07-16 23:42:13.809214 | 20
jdoe | AAA | 2006-08-16 | 2006-08-25 11:57:17.394854 | 20
jdoe | BBB | 2006-08-16 | 2006-08-25 11:57:17.394854 | 20
jdoe | AAA | 2006-09-01 | 2006-08-28 12:38:42.486513 | 20
jdoe | BBB | 2006-09-01 | 2006-08-28 12:38:42.486513 | 20

Basically, for effective='08-16-2006', it only gets the latest inserted
record (using tstamp) for that effective date, which is 2006-08-25 11:57:
17.394854.

So what is the quickest way to do this?
I can always do:
Select * from Table t where tstamp=(select max(tstamp) from Table t2 where
t2.name=t.name and t2.effective=t.effective)
but it takes so long since this is a huge table.

Any suggestions?