In one area of our application, we would like to be able to capture an
update to a master table, and select the target replication table based
on some key value in the update data, e.g. "if key_field == A, replicate
to table X on host A; if key_field == B, replicate to table X on host
B", etc.

I realize that slony doesn't do this currently, but I'm wondering if
anybody else would find a feature like this desirable. A new table could
be added, with an fk to sl_table, to capture the info about the
partitioning key/value->target table/host mapping, though supporting
multi-columm partition keys would make this more complicated. Then the
code in remote_worker would need to know about this information. Of
course, you'd have to be able to express these relationships in slonik,
as well, so I know the whole thing isn't that simple. 

Are there any obvious show-stoppers that make it impossible to implement
something like this?

-  DAP
====================================================== 
David Parker    Tazz Networks    (401) 709-5130