[wp-hackers] Rebuttal (re: Meta tables: Take 5)

Jacob Santos wordpress at santosj.name
Fri Jul 24 15:38:30 UTC 2009


I understand your argument that having a single table for meta is an 
entirely bad idea based on the following assumptions.

1. Having hundreds of millions of rows is a performance problem for 
searching, insertion, etc.
2. Having multiple blogs using the same table is a bad idea because the 
size of the single table increases exponentially.
3. It quite frankly just plain sucks and is "bad design."

Let me refute these claims, and if you have any further ones, then let 
me know as I don't want to put up a straw man. These are just the ones 
that I've heard in the past as to why single table solutions are 
terrible. You might have others.

1. With proper indexes, performance problems shouldn't be an issue. 
Having millions of rows in majority of cases shouldn't hinder most of 
the use cases with the correct indexes to search on.
2. I would probably state that having multiple meta tables for each blog 
would be a good idea as it doesn't have to be tied to just all of the 
blogs for a single table but for a single blog for MU installations.
3. It is in my opinion that having multiple tables with the same 
structure and tiny amount of rows is even worse design than a single 
table. Alas, a compromise can probably be found between a single table 
and multiple tables.

I will contend that for the majority of non-MU and plain WordPress 
installations, having a single meta meta table will never even get close 
to reaching 100,000 rows, let alone the millions that would be required 
to degrade performance.

I was actually going to flame you based on my (now correct) assumption 
that it would be creating new tables. I think that it would be against 
my doing so, or at least not publicly (the flame email should be 
arriving to your email soon).

Jacob Santos

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