[wp-hackers] multiple databases vs different database prefixes

[Mike Schinkel]

Ken,

> I will not be using the multisite feature. These are 300+ separate WP installations.
> 
> Question: Is it better to create each site with it's own database, or should all 300+ sites be in one database but each site having different table prefixes? 
> 
> My concern is scaling.  I am concerned that running all 300+ sites in one database would slow down performance vs having separate databases. Although, having all tables be in one database is very convenient if I ever need to share information between sites.


After Paul's response I re-read the original email.

The fact is the multisite creates multiple databases with different table prefixes for each site.  And with the addition of HyperDB[1] you should be able to use multiple databases if and when you need to all with one WordPress multisite installation that will make managing all the sites much easier.  And if you find that having them all on one server is too much then you can create multiple instances of WordPress multisite installations, i.e. 3 servers with 100 sites each.

If you are really concerned about about this you might also want to talk to WP Engine[2] about hosting as they seem to be focused on hosting that requires performance and scalability.

-Mike
[1] http://codex.wordpress.org/HyperDB
[2] http://wpengine.com/