If you are going to work with the GNOME-DB sources, you'll first find a bit lost, as there are plenty of directories. Here is a small guide:
Documentation. This directory contains one subdirectory for each locale.
IDL files. You may use them to generate a custom client (or server).
Client library. A wrapper library around the CORBA stuff. It implements most of the housekeeping, buffering and cursor control. Note that in a later version cursor control may also be implemented in the server.
Widget Client Library. This is a library containing GTK+/GNOME widgets that let you easily integrate the GNOME-DB API into GNOME applications.
Scripts and programs for helping in the development of GDA-related applications.
CORBA server which implements LDAP access. Currently empty.
General setup and configuration tools. It will contain an ODBC manager and stuff like this. Currently empty.
CORBA server for the MySQL database. Currently a very small part is implemented. More to come.
CORBA server for the ODBC databases. Currently the most developed server. It allows you to access Solid and Postgres databases. If an ODBC driver is available for your database you might try this server to access it.
CORBA server for the PostgreSQL databases. It makes use of the PostgreSQL native API to provide a CORBA-based access to the database.
CORBA server for the Sybase databases. Currently empty.
CORBA server for the Oracle databases.
ODBC manager client library. Parses the ~/.odbc.ini file and links the correct shared ODBC library to the server. It works, but I'd like to rework it to use standard GNOME configuration files.
ODBC glue library for Postgres. There could be a native interface, but this was available already so i used this.
SQL Front-End application. This is an application making use of all the power provided by the GDA client and GDA UI libraries. It provides an easy way for querying and managing your databases.
Test programs for various pieces of the system. Check them to get a breeze of what can be done with the GDA libraries.