My aim is to write a collection of many webapplications, like google services (mail, calendar, docs, ...).
It will be written in PHP with Zend Framework (Version 2). I use MySQL to store data.
The service collection should always be extendable (new services) easy.
Is it useful to provide a own database for every service? They would have few tables only (more or less 3). That would mean that I have to use Zend's multiple database adapter.
The other solution is to use one big database for the hole collection. The advantages are that I can use foreign keys between the tables of different applications. I also could use the default database adapter.
All the applications are enmashed with each other close.
What makes more sense?