[wp-hackers] Confusion About the **Meta Table

[Otto]

On Sat, Jan 15, 2011 at 10:33 AM, Alexander Hempton-Smith
<hempsworth at gmail.com> wrote:
> Why was it decided that there would be individual meta tables for each
> mother table? Why not one universal meta table for all of the others?
> With a reference on each record to what it's parent table is.
>
> I ask because I'm designing the db for an app I'm building and
> considered having one meta table to serve all the others (where
> necessary)

Speed in joining the meta tables to their parent tables. Joining the
tables is a lot faster when you don't need a WHERE clause to select
based on the type of meta data you're wanting to join.

-Otto