What Are the General Rules on Data Consistency

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What Are the General Rules on Data Consistency? - Oracle DBA FAQ - Understanding SQL Transaction Management

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A

All SQL statements always work with a snapshot of the database to provide data consistency.
For READ WRITE transactions, the snapshot is taken when each statement starts.
For READ ONLY transactions, the snapshot is taken when the transaction starts.
The snapshot never include uncommitted changes from other transactions.
The snapshot always include uncommitted changes from its own transaction.

2007-04-17, 5318👍, 0💬

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