Confusion

Hello list,

Can someone please fill me up on the state of affairs with ODBC support?
I tried to search docs and FAQs but it is confusing as hell.

I need to understand relation between unixODBC per say and
--with-unixODBC option. The latter seem to produce libpsqlodbc.so, how
it is different from libodbcpsql.so, produced when I build standalone
unixODBC? Which one should be used? Release notes in unixODBC package
suggest there have been bug fixes related to Postgres driver lately...

Also any hints about usage with PHP would be very appreciated. Both
postgres and unixODBC appear to have odbc.ini and odbcinst.ini files,
which ones should be used to set envars in the PHP scripts?

Thanks,
- igor