Walter Meester
HoogkarspelPays-Bas
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Codage, syntaxe et commandes
Hi Walter,
>Actually it is 9 (maximum of 9 EXIST clauses in VFP8).
You have other two table for the join, and 7 max EXISTS/NOT EXISTS.
>I think in these extreme cases you have to look really well about performance penalties becauses you're talking about a >lot of potential records and hardly can avoid full table scans. Note that your solution is also limited (to 24 items) >unless you choose to join it with a custom cursor.
Yes, but i have not indicated the solution as the better solution for the general case.
>There is no need to be picky, I'm just trying to be constructive.
Sorry, but the impression has ahother.
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If you remove the hypothesis that table on exists() have a index for the join field,
then VFP must build 1,2,...7 temporary index, and for large table this can to be very time consuming.
If you not put constraint hypothesis, the discussion it can go ahead to the infinite.
Best general solution, without hypothesis, not exist.
Fabio
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