Very educational article. Lately I have to deal with performance issues created by similar queries as given in this article. I like to read more about subqueries and their alternatives. For instance, could row_number be used to search in a string-column of a table? I now have something like:

DECLARE @var1 AS String, @var2 AS String

SELECT c1, c2, c3 FROM Table

WHERE StringColumn LIKE '%' + @var1 + '%' AND StringColumn LIKE '%' + @var2 + '%'

I'm trying several aproaches and I'm sure I'll either figure it out or conclude it can't be made pretty.

Tnx again.