What Is a Data Lock

Q

What Is a Data Lock? - Oracle DBA FAQ - Understanding SQL Transaction Management

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A

A data lock is logical flag the Oracle server is placed on data objects to give an exclusive right to a transaction. Statements in other transactions needs to respect data locks based on certain rules. Rules on data locks are:

SELECT query statements do not create any data locks.
INSERT, UPDATE, and DELETE statements create data locks on the affected rows.
Data locks are released when the owner transaction ends.

2007-04-17, 5160👍, 0💬

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How Data Locks Are Respected
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