Funny... I just read the WIKI article on the subject of RTFM and they don't know what the origin is.  I don't either but the first time I heard it...

I just remembered that on every WordPress.com article that I posted a comment to, I had to subscribe to that article.  I hope we don't have to do that for...

You'd likely get help more quickly if you posted your data in a readily consumable format.  Lot's of people like to test their solutions before posting an answer.  See the...

APPLY works out to be the same as a correlated subquery that can return more than 1 row for each correlation.

I know this isn't the helpful answer that you're looking for but I'd start looking for a different tool to use.  The one you have is way too demanding.

Heh... write code that runs faster. 😉