Quote:
| You could use just one. I would not use one with 30 but 2 or 3 would be fine. MySQL is not SQL and can not handle the same amount of data. Plus you are just asking for trouble with that many because a MySQL database is limited to 2GB of storage. 2GB is the limit but I would say try to avoid going over 1.5GB |
The limitation is due to the operating system (linux) or the partitioning of the hard drive - SQL has the exact same problem. Also, the limits are per table not database (each table has it's own file)
As for the original question: Yes, you append the table prefix
Visit the following link and scroll down to single database
http://codex.wordpress.org/Installing_Multiple_Blogs
as always, just my two cents