Subject Re: [firebird-support] is distinct from - not indexed
Author Thomas Steinmaurer
> 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

Download LogManager Series, FB TraceManager today!
Continuous Database Monitoring Solutions supporting
Firebird, InterBase, Advantage Database, MS SQL Server
and NexusDB!