Limitations of mod_dbd - single server per vhost

[Mikhail T.]

From reading the module's documentation 
<http://httpd.apache.org/docs/2.4/mod/mod_dbd.html>, it seems, a single vhost 
can only use one DB-server (and only with one set of credentials): only a single 
DBDriver and DBDParams is possible, for example.

Also, the syntax of mod_rewrite's dbd/fastdbd maps 
<http://httpd.apache.org/docs/2.4/rewrite/rewritemap.html#dbd> doesn't even 
allow to specify the DB-server, implying, once again, there can only be one in a 
given context (entire server or virtual host). The missing capability could be 
useful to someone, who would want, for example, to check a local SQLite-database 
for data and, failing to find anything, attempt a query against a remote MySQL 
or Sybase server. Other enterprises may want to talk to multiple remote servers 
(potentially using different drivers).

I would've filed an enhancement-request, but, perhaps, this was already 
discussed here and there are some good reasons for the limitation? Thanks! Yours,

   -mi