What Is a Dead Lock in Oracle

Q

What Is a Dead Lock in Oracle?

✍: FYIcenter.com

A

A dead lock is phenomenon happens between two transactions with each of them holding a lock that blocks the other transaction as shown in the following diagram:

(transaction 1)                (transaction 2)
update row X to create lock 1
                               update row Y to create lock 2
                               update row X
                               (blocked by lock 1)
update row Y
(blocked by lock 2)

(dead lock created)

⇒ How Oracle Handles Dead Locks in Oracle

⇐ Show Existing Locks on the Database in Oracle

⇑ Understanding SQL Transaction Management in Oracle

⇑⇑ Oracle Database Tutorials

2019-08-08, 2299🔥, 0💬

User Role: Group of Privileges in Oracle
What Is a User Role in Oracle? A user role is a group of privileges. Privileges are assigned to users through user roles. You create new roles, grant privileges to the roles, and then grant roles to users. ⇒ System Defined User Roles in Oracle ⇐ User Account and Schema: One-to-One Relation in Ora... 2019-07-30, 3176🔥, 0💬

User Account and Schema: One-to-One Relation in Oracle
What Is the Relation of a User Account and a Schema in Oracle? User accounts and schemas have a one-to-one relation. When you create a user, you are also implicitly creating a schema for that user. A schema is a logical container for the database objects (such as tables, views, triggers, and so on) ... 2019-07-30, 3153🔥, 0💬

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, 2613🔥, 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, 2550🔥, 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, 2454🔥, 0💬

Show Existing Locks on the Database in Oracle
How To View Existing Locks on the Database in Oracle? As can see from the pervious tutorial exercise, performance of the second session is greatly affected by the data lock created on the database. To maintain a good performance level for all sessions, you need to monitor the number of data locks on... 2019-08-08, 2430🔥, 0💬

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, 2393🔥, 0💬

What Is a Dead Lock in Oracle
What Is a Dead Lock in Oracle? A dead lock is phenomenon happens between two transactions with each of them holding a lock that blocks the other transaction as shown in the following diagram: (transaction 1) (transaction 2) update row X to create lock 1 update row Y to create lock 2 update row X (bl... 2019-08-08, 2300🔥, 0💬

User Account and Attributes in Oracle
What Is a User Account in Oracle? A user account is identified by a user name and defines user's attributes, including the following: Password for database authentication Privileges and roles Default tablespace for database objects Default temporary tablespace for query processing work space ⇒ Use... 2019-07-30, 2237🔥, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.