[Koha] Database Structure and Full Features

Good day folks! We're currently evaluating KOHA as a solution for the Union Catalog project of the SciNET (Science Network) here in the Philippines. I'm interested with the database structure and the detailed features of KOHA. I tried searching koha's site but I can't find those information. I believe KOHA is an excellent system. I just hope anyone can help me find the data that I need. Regards, Domingo Genaro P. Tamayo STII-DOST