Walter Meester
HoogkarspelPays-Bas
Information générale
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Markus,
>the fact of the matter is that Rushmore only works if there are indexes on all the expressions involved in a query. If SET DELETED is ON, the expression "AND NOT DELETED()" is internally added to every query you run (simplistically spoken).
>This means that no matter how well you create your query, you will never be able to take advantage of Rushmore since it's simply turned off (even if there isn't a single deleted record involved in the entire operation).
With all do respect, i don't think you understand the working of rushmore. If only 1 part of your expression is optimizable (combined with AND) rushmore will optimize this. I strongly suggest reading 'Optimizing Rushmore Expressions' chapter 15 (in the developersguide of VFP 5.0)
Your misunderstanding of rushmore is exactly the reason i wrote this message. An expression does not have to fully optimizable which don't have to mean that it would be slower than a fully optimizable expression
OIW the deleted tag is NOT required to take advantage of Rushmore. In fact the deleted tag may be much of a burden in a lot of cases.
regargs,
Walter
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