Processing Tables containing tree-like data

Hi,

I have a table which looks like this:

id    info    parentid
0    <God>    0
1    Adam    0
2    Cain    1
3    Abel    1
4    Seth    1
5    Enosh    4
....



I am looking for a fast and efficient way of finding ALL the descendents
of any particular node, to unlimited depth.

Is there a standard database trick for doing this efficiently ? Writing
a recursive function would be extremely inefficient for repeated
queries.

Thanks,


Netzach