At the moment I have not tracked down what causes the different behaviour under VFP8, as the query I have seen the problem in uses complex sub functions and macro substitutions. The query is conducted on a cursor without an index. I will attempt to produce a replicable example.

In simple cases, my original post was wrong - the example given is identical under VFP6-7. All this does raise the question, though, why is the logic processing of an SQL Select command so much more inefficient than an IF command?