More tables in the existing DB vs. creating a new DB

[arikgub]

I'm running Apache server + mySQL database.

I am going to create a WordPress blog on my site. I can create it within the existing database (currently not related to the blog), in which case more tables will be added to the database, or I can create a new database dedicated to the blog.

What are pros & cons of adding more tables to the existing database versus creating a new one? Are there any server performance (speed) implications?

Thanks.

[physics]

IMO you should create a new database. The blog and the rest of your site are really different entities so they should have different databases. Also, there are security implications, i.e. if there is some sort of WordPress vulnerability it might affect the rest of your site's db if you combine them. Not sure about performance but I can't see how it would make things faster to combine them...