WordPress creating unacceptable server load

Hello, my host, one.com, recently decided to pull the plug on my blog, claiming that my MySQL queries created too much load on the server. They provided me with a fairly unspecific explanation suggesting that the problem arises from this query (which does not tell me much):

> Query SELECT comment_ID, comment_author,
> comment_author_email, comment_author_url,
> comment_date, comment_content, comment_

Furthermore, they are “99% sure that it is an ORDER BY that creates the problem”.

Admittedly, I am fairly – to put it mildy – inept when it comes to database questions, so I would appreciate any pedagogical suggestions as to how I might go about solving the problem and resuscitating my blog.

Thank you.