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Which statement is 'Better'
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Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Versions des environnements
Visual FoxPro:
VFP 6
Divers
Thread ID:
01048319
Message ID:
01335280
Vues:
52
Sergey,

Woohoo I may print and frame this one. *bg*

>>Sergey,
>>
>>>It doesn't apply to EXISTS subqueries because SQL Server doesn't retrieve any data for them.
>>
>>That is not our experience based on examining the I/Os that occur. I'll see if I can come up with some examples against northwind later tonight.
>
>Hi David,
>
>It turned out that I was wrong. See EXISTS Subqueries: SELECT 1 vs. SELECT *
>Quote: "The QP will take and expand all *'s early in the pipeline and bind them to objects (in this case, the list of columns). It will then remove unneeded columns due to the nature of the query."
>Recomendation: Use something like "SELECT 1 ..."
df (was a 10 time MVP)

df FoxPro website
FoxPro Wiki site online, editable knowledgebase
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