Data model for Postfix v2

Just asking in case anyone has this info...

Does anyone have a complete and working data model that allows Postfix
v2 to lookup domain/user lookups (including virtual domains and users).

I've got mostly working data model cobbled together over a period of
time, but I can't get my config/db model to allow mail forwarding for
local users to a remote mail address (aliasing).

I know that this is just a config issue, but I think the combination of
my data model and lookup table configs (in main.cf) and sql statements
is screwed.

If anyone has a decent model that they'd be willing to share with their
main.cf table lookup entries (that use the db) and the extra .cf files
that detail the sql statements used, could they let me know?

Thanks

John Sidney-Woollett