Daniel,

I have only one simple answer (don't know about your other
questions). Create an DESCENDING index on your column and
MAX() will be significantly faster, whereas an ASCENDING
index speeds up MIN().


Regards,
Thomas Steinmaurer
IB LogManager 2.1 - The Logging/Auditing Tool for InterBase and Firebird
http://www.iblogmanager.com

> I have an indexed column where a simple "SELECT MAX(<column>) FROM
> <table>" generates a full table scan. I guess it has to do with the
> index compresion stuff I read somewhere. This particular table has
> over 1.5 million records (the database has plenty of super populated
> tables).
>
> Should I create an ascending AND a descending index to obtain decent
> perfomance? What about storage... will it duplicate?
>
> BTW, how does index compression affect negatively on geographic
> coordinates (lat/lon, UTM)? If there is a problem, is there any
> workaround (perhaps storing hours, minutes, seconds instead of
> decimal notation?).
>
> TIA.
>
> Greeting,
> Daniel Berstein
>
>
>
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