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Databases,Tables, Views, Indexing and SQL syntax
>>A former programmer at my company had applied an alltrim to an indexed field. When I removed the alltrim the report that uses the field ran several times faster. This alltrim seemingly nullified the index on the field. Is there any explaination to this?
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>>Thanks for all replies.
>>
>>Mike
>
>Yea, I think so...
>
>The program itself was most probably *NOT* using the ALLTRIM(IndexedFieldName) expression in its FOR or WHERE clause(s).
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>You'll want to make sure that there are not other parts of the application that slowdown because of your change, and if they do then I suggest that you change them to remove the ALLTRIM() in their expressions also .
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>It is general concensus that ALLTRIM() is NOT useful/sensible in a TAG expression anyway, so your first step was a good one (though no doubt lucky too).
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>good luck,
>
>JimN
Michael,
To go a little further with what JimN says, unless you've got spaces at the beginning of your field, the ALLTRIM() is useless. As Craig pointed out, VFP uses fixed-length indexes, so the key value will be padded back out to the maximum field size.
You can, however, seek on a value that is less than the total length of the field, but whether FOUND() is .T. will depend on your settings.
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