when is the time to make a new database on a php site?

[wheeler]

I'm used to the concept of working with functions and php files, where there is a need to organise things into logical files/functions... rather than a 10,000 line index.php file.

But I have a situation where it seems like I should start a new database, because even though the applications will talk to each other down the development track, they are also stand-alone entities. I know its possible to work with different databases at the same time in php, but it is a bit of a pain to do... with connection handlers, extra db users etc.

What is the general consensus? To have a very large database with dozens of tables, or to split it off.

[TheAnarchist]

It really comes down to whether it would work more logically one way or the other.

If each application is a standalone entity, I would suggest that seperate databases be used for each. What will you do in the event that you need to seperate one of these applications? Take a copy of the entire database with it?

[wheeler]

I guess that is a point that it makes it more difficult to backup/seperate with only 1 database

[cranial-bore]

You don't necessarily need to make 2 connections. As long as the DB user has access to both you can talk to both with a single connection.
You can use mysql_select_db or just specify the DB name in query. JOINS across databases are also possible.

cPanel allows a given user to access multiple database, though I think Plesk does not.

Just decide what's logical. It may be confusing to have a lot of unrelated tables sharing a DB, particularly when viewing an alphabetical list. I have no qualms about dividing my data.

[wheeler]

You don't necessarily need to make 2 connections. As long as the DB user has access to both you can talk to both with a single connection.
You can use mysql_select_db or just specify the DB name in query. JOINS across databases are also possible.

cPanel allows a given user to access multiple database, though I think Plesk does not.

good point, plesk I think is pretty hopeless in managing databases, from memory you can't even select permissions for the db user, they must have complete permission.