Hello Thomas,
again thanks a lot for your help! Best regards and a nice weekend. Olaf > If I select some fields from mytable with ,where field = XX' or ,where field >> XX', the indexed fields were read indexed (displayed from IBExpert). But > If I select some fileds from mytable with 'where field is distinct from XX', > the read is not indexed. > > > > It is already okay? It's an inequality operator, thus, it won't use an index. The same goes for <> or NOT. Performance wise, try to use an equality operator (or smaller/greater) whenever you can. -- With regards, Thomas Steinmaurer Upscene Productions http://www.upscene.com http://blog.upscene.com/thomas/ Download LogManager Series, FB TraceManager today! Continuous Database Monitoring Solutions supporting Firebird, InterBase, Advantage Database, MS SQL Server and NexusDB! [Non-text portions of this message have been removed]
