[wp-hackers] Meta tables: Take 5

[Mike Schinkel]

On Aug 5, 2009, at 6:31 PM, Joseph Scott wrote:
> I like the idea of being able to get a list of the current meta  
> types by querying a very small table.  I would be concerned about  
> the potential of the JOIN to kill performance in some cases:
>
> 	http://www.mysqlperformanceblog.com/2008/01/24/enum-fields-vs-varchar-vs-int-joined-table-what-is-faster/

 From everything I know about how indexes are created and used, his  
results seem completely counterintuitive.  His use of everything being  
in memory leads me to question real world validity.  But since I don't  
have time to build a valid benchmark and do my own research, I'll  
accept his results as stated.

> Having a good API could take care of this though, by keeping a  
> dictionary table that listed all of the current meta types (and  
> perhaps some data about them, like where they came from: WP, Plugin,  
> Theme, etc.) and still storing the meta type in the meta table  
> itself.  This would allow for meta queries without having to join  
> against the dictionary table.

True.

-Mike Schinkel
WordPress Custom Plugins
http://mikeschinkel.com/custom-wordpress-plugins/