What Is a Data Lock in Oracle

Q

What Is a Data Lock in Oracle?

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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.

⇒Understanding SQL Transaction Management in Oracle

⇒⇒Oracle Database Tutorials

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