I don't know if it's a written rule but in my experiences, whenever I use a "length-changing" function it slows the queries down significantly. "Length-changing" being for instance the AllTrim() function where the actual length would vary from record to record. I've done stuff like PadL(Upper(Left(Last,At(" ",Last)))), 25," "), where PadL will convert the lengths to a unified size. I don't think it operates faster than say Upper(Last) but it will operate faster than Upper(Left(Last, At(" ",Last))).

Hope that helps a little.

Aloha,

James

>Hello!
>I have a FoxPro application, that handles large volume of data. The tables have simple indexes defined on its fields. In an attempt to speed up my queries, I modified my indexes to match my queries. I read about Rushmore optimization and altered the indexes so that they obey the Rushmore principles.
> - My indexes look exactly like the query.i.e if my query defines a criteria as 'Alltrim(Upper(fieldname))', I have an index defined as alltrim(upper(fieldname)). I did this because I read that the optimization will be turned off, if the indexes are altered.
>
> - I have avoided the use of $,At(),Empty() functions.
>
> - Most tables have 4-7 indexes defined.
>
>After making these changes, my quries take longer. I am trying to find out why this happens. Any help would be much appreciated.
>
>Thanks in advance.
>
>Ria