When I'm in Windows, I use the excellent MicroOLAP Database Designer for PostgreSQL, but its not open source or multiplataform.
Do you know or can recommend me an alternative to this software, that I can use in Linux?
EDIT: Just to clarify, I don't want to use wine to emulate MicroOlap for PostgreSQL, it doesn't work too well, I would prefer something native, or Java based.
pgDesigner is a database design application for PostgreSQL, for versions 7.x and 8.x.
pgDesigner provides the following features: