Subject | AW: [firebird-support] is distinct from - not indexed |
---|---|
Author | Olaf Kluge |
Post date | 2011-08-12T17:58:19Z |
Hello Thomas,
again thanks a lot for your help!
Best regards and a nice weekend.
Olaf
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]
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 ,wherefield
>> XX', the indexed fields were read indexed (displayed from IBExpert). ButXX',
> If I select some fileds from mytable with 'where field is distinct from
> the read is not indexed.It's an inequality operator, thus, it won't use an index. The same goes
>
>
>
> It is already okay?
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]