Java needed to run LibreOffice Base Database? No with Firebird SQL
You can try to use the Firebird Database within LibreOffice which doesn’t need Java. This feature is still marked as experimental. Firebird Databases are available since LibreOffice 4.2. (see the release notes for further information
To turn the experimental features on, you have to go to the Settings –> LibreOffice –> Advanced –> “Enable experimental features” (see screenshot bellow)
Then you can uncheck the Java from the same Dialog.
Original question and source is on ask.libreoffice.org
To make Firebird Embedded default database in the new database dialog open Expert Configuration and change this key
org.openoffice.Office.DataAccess/EmbeddedDatabases/DefaultEmbeddedDatabase/Value to sdbc:embedded:firebird