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Modifying stored procedures
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À
05/06/2002 11:23:33
Hilmar Zonneveld
Independent Consultant
Cochabamba, Bolivie
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00664934
Message ID:
00665303
Vues:
24
Hi, Hilmar!

>>
Can you briefly explain what is a "dirty read"?
<<

"Dirty read" is the possibilitiy of all xBase databases to be able to read a record which is locked by another!
This works due to a technical trick:
- Locks are setted on a specific area of the DBF file.
- But not the real location of the locked record in the DBF file is locked, but a virtual region outside of EOF.
- If anybody other try to make the same virtual lock, it denied.
- But if anybody want's to read the locked record - it works!

BTW: This is the history, I'm not sure about behind the scenes of the current VFP versions. And I don't know how backend databases like SQL2000 work!

So far!
SeBaFlu
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