> From: Paul Schmidt
> If I have the following query:
>
> SELECT ORDER_ID FROM ORDERS WHERE ORDER_DATE > '2002-07-01'
> ORDER BY ORDER_ID DESC;
>
> How big a sort file should I guess to end up with, providing neither field is indexed.

Sort file will contain only records that satisfy WHERE criteria (i.e. 1000 records).
Each row will contain all fields (uncompressed) from SELECT clause (i.e. order_id).
(and possibly from ORDER BY clause, because IB/FB, unlike SQL standard,
allows sorting by fields not listed in SELECT clause).

Because sort file contains uncompressed data, you can easily end up with sort file
much larger that whole database (when using long VAR/CHAR fields).

Ivan
http://www.volny.cz/iprenosil/interbase