[development] Requiring node revisions

[Derek Wright]

On Jun 7, 2007, at 12:38 PM, David Metzler wrote:

> If that's true, then the overhead of a JOIN on an empty table would  
> be significantly different than the join on a table that has a  
> million rows in it, regardless of the filter criteria, yes?

no:

1) {node_revisions} *ALWAYS* has at least 1 record for any given  
node.  that's where title, body, etc are stored.  please read the  
schema if you have further questions.  therefore, the only site with  
an empty {node_revisions} table is the site with no nodes at all.

2) {node_revisions} has an index on nid, and we always JOIN on nid.   
by and large, the cost of this JOIN is constant, regardless of the #  
of rows in the table, since the JOINs basically always use the index.

cheers,
-derek (dww)