Subject Re: [firebird-support] SQL - performance
Author Martijn Tonies
> >The reason I wrote that, is that expression indices aren't needed
> >for this to be optimized.
> >
> >I'm not fully aware of what expression indices should be able
> >to do anyway. I picture usage as UPPER(column) = 'value'
> >and an Upper(Column) index...
> ..or a SUBSTRING(Column FROM m FOR n) index...?
> (Just getting back to the original question...whether one form of query
> faster than the other...not whether either offering was IN(best_choices).

Oh, there should be an index on that column... said that already ;-)

With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL
Upscene Productions