Hi,
Have many tables in a data warehouse that just have a snapshot time to differentiate between each set of records for a particular item. I am trying to work out the best way to select only the latest record for each item (the latest snapshot).

Here is a simple example table

TYPE,SNAPSHOT_TIME,DESCRIPTION
B,14/04/2003 23:01:42,Room
C,14/04/2003 23:01:42,Club
B,17/11/2003 23:57:46,Meeting Room
A,17/11/2003 23:57:46,Temporary
N,17/11/2003 23:57:46,National Office

Select would retrieve four records with record type of B having the description of Meeting Room.

Many Thanks

select TYPE,SNAPSHOT_TIME,DESCRIPTION
from example as foo
where SNAPSHOT_TIME =
( select max(SNAPSHOT_TIME) from example where TYPE = foo.TYPE )