docbook xml into/out-of sql-tables

Greetings,

I'm looking for pointers to info on storeing / retreving docbook, or other
document type systems, in sql tables.

My searchs on docbook & sql etc turn up info on manuals etc for a system in
docbook, which is not at all what I'm looking for. (e.g. postgresql doc are
in docbook form...)

You could think of the issue as the guts portion of a content management
system, but not the server, web gen, etc.

Thanks in advance,

..Otto