when to use dbprefix

[eluser]WanWizard[/eluser]
The idea behind a prefix is that you can have multiple application (not only CI applications) use the same database. So all tables of App1 will be prefixed with "app1_", and all tables of App2 with "app2_".

That is completely different then two CI installation using the same table. In that case, assuming that the prefix for that table is different then the default prefix for the application, define a second database group in your database.php setup for the same database but with the other prefix, and use that to access the shared table. Check "Connecting to multiple databases" on http://ellislab.com/codeigniter/user-gui...cting.html.