What Is a Data Lock in Oracle

Q

What Is a Data Lock in Oracle?

✍: FYIcenter.com

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.

⇒ How Data Locks Are Respected in Oracle

⇐ Supported Transaction Isolation Levels in Oracle

⇑ Understanding SQL Transaction Management in Oracle

⇑⇑ Oracle Database Tutorials

2019-08-19, 3216🔥, 0💬

Set a READ ONLY Transaction in Oracle
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Restrictions in a READ ONLY Transaction in Oracle
What Are the Restrictions in a READ ONLY Transaction in Oracle? There are lots of restrictions in a READ ONLY transaction: You can not switch to READ WRITE mode. You can not run any INSERT, UPDATE, DELETE statements. You can run SELECT query statements. The tutorial exercise below shows you some of ... 2019-08-19, 3394🔥, 0💬

How Oracle Handles Dead Locks in Oracle
How Oracle Handles Dead Locks in Oracle? Oracle server automatically detects dead locks. When a dead lock is detected, Oracle server will select a victim transaction, and fail its statement that is blocked in the dead lock to break the dead lock. The tutorial exercise below shows you an example of s... 2019-08-08, 3298🔥, 0💬

General Rules on Data Consistency in Oracle
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What Is a Data Lock in Oracle
What Is a Data Lock in Oracle? 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 ... 2019-08-19, 3217🔥, 0💬

Show Existing Locks on the Database in Oracle
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Supported Transaction Isolation Levels in Oracle
What Are Transaction Isolation Levels Supported by Oracle in Oracle? Oracle supports two transaction isolation levels: READ COMMITTED (the default option). If the transaction contains DML that requires row locks held by another transaction, then the DML statement waits until the row locks are releas... 2019-08-19, 3154🔥, 0💬

Experiments of Data Locks in Oracle
How To Experiment a Data Lock in Oracle? If you want to have some experience with data locks, you can create two windows running two SQL*Plus sessions. In session 1, you can run a UPDATE statements to create a data lock. Before committing session 2, switch to session 2, and run a UPDATE statements o... 2019-08-08, 3113🔥, 0💬

What Is a Dead Lock in Oracle
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