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West Wind Web Connection
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>>I don't know. I've read that having an index on DELETED() can be a mistake, as you suggested in your FAQ. Maybe if I have a small number of non empty D40CkNo instead of all empty this would change the results.
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>If I understand correctly, you still have your index on DELETED().
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>What may be happening is something like this:
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>A) If you test on an optimizable query (Field = " ", or something), VFP gets values from the index for both expressions: 1) NOT DELETED(), 2) Field = " ".
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>B) If the expression is not optimizable (Empty(Field)), VFP gets values from the index only for the second expression (Empty(Field)).
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>In both cases, VFP gets the index keys for almost all records (??? this depends on the data in your tables).
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>It would seem that in case (A), VFP has more work to do. Once more, full optimization is slower. The situation might change radically if you killed the index on DELETED().
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>I suggest you re-run the tests without this offensive (for me) index (if you haven't done so already). I also suggest that you do the test under real-world conditions, i.e., presummably, over the network.
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>Hilmar.
Actually, I don't have an index on DELETED() but yesterday when I was running tests all the counts were coming 13.5 seconds, 15.9 seconds. I couldn't figure out what was going on. Of course I had DELETED ON. As soon as I turned it off, it was normal.
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