>> I seriously doubt Firebird is anything like ColdFusion in this area,
>
> My interpretation of the Celko book (plus the link) is that this was
> not specific to Coldfusion but applied to DB server software generally.
>
> I was interested to know if there was a pre-defined standard somewhere
> of the execution order for SQL engines (one would have thought so)
> and, if not, then whether there was variations between the
> implementations.

It is misinterpretation. SQL standard does not tell what the execution order
should be, but that the result should be as if the clauses were executed
in specific order. Each engine is totally free to implement whatever
order thinks is the best for it, as far as the returned result is as expected.

Ivan