Re: Help with SQL statement

Birgitta Hauser wrote on 06/12/2006 12:58:36 AM:

When concatenating several fields no indexes can be used, because a 

"new" 

field is created and indexes only can be used for existing fields.
But using GROUP BY may cause ALL rows being. Using DISTINCT may be the 
better solution, because it can work as SETGT/READ in RPG. And if there 

is 

an index that consists only of the selected fields an IOA (index only 

access 

= the fastest way to access data, because all necessary information is 

in 

the key and no additional access to the rest of the row is necessary) 

can be 

performed.

Thanks Birgitta, that is the kind of thing I'm interested in learning 
about.  From now on I'll definitely be trying to think "could I use 
DISTINCT instead?" when I'm doing a GROUP BY.

Thanks again,
Adam

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