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Deleted Records cannot be ignored?
Message
Information générale
Forum:
Visual FoxPro
Catégorie:
Autre
Divers
Thread ID:
00082386
Message ID:
00083544
Vues:
29
>I have an app that does queries on a 300 meg table. It's legacy 2.x coding, but it sets the order before every query to the left side of the WHERE clause and runs magically fast...But perhaps with no order set it will be even faster since the coded order may be redundant?
>
>I guess the question here is does SQL always ignore a coded order and do its own index search?

Without hard facts to back my opinion up.... My guess is that if your SQL is relatively simple, using only a single WHERE clause, then setting the file to the correct index in advance might speed it up and won't do any harm. However, if you have several WHERE clauses, each using a different index, then you're better off letting VFP handle it. The SQL engine seems to handle these orderings in its own fashion - NOT one that's documented or even logical.
Barbara Paltiel, Paltiel Inc.
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