What Is a Dead Lock in MySQL

Q

What Is a Dead Lock in MySQL?

✍: 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)

⇒ Experiment with Dead Locks in MySQL

⇐ Error: Lock Wait Timeout Exceeded in MySQL

⇑ Transaction Management: Commit or Rollback in MySQL

⇑⇑ MySQL Database Tutorials

2017-04-28, 2516🔥, 0💬

Error: Lock Wait Timeout Exceeded in MySQL
What Happens to Your Transactions When ERROR 1205 Occurred in MySQL? If your transaction receives the "Lock wait timeout exceeded" - ERROR 1205, MySQL server automatically terminates your transaction and rolls back your data changes of the entire transaction. This is why the error messages tells you... 2017-04-28, 5279🔥, 0💬

Locks, Timeouts, and Deadlocks in MySQL
What Are Impacts on Applications from Locks, Timeouts, and DeadLocks in MySQL? If you are using transactions with REPEATABLE READ isolation level and transaction safe storage engines in your applications, data locks, lock timeouts, and dead lock detections will impact your application in a concurren... 2017-07-21, 3687🔥, 0💬

Change Transaction Isolation Level in MySQL
How To View and Change the Current Transaction Isolation Level in MySQL? If you want to view or change the current transaction isolation level, you can use the following commands: SELECT @@TX_ISOLATION FROM DUAL; -- Viewing the current transaction isolation level. SET TRANSACTION ISOLATION LEVEL lev... 2017-08-08, 3683🔥, 0💬

What Is MySQL
What Is MySQL? MySQL is an open source database management system developed by MySQL AB, http://www.mysql.com. ⇒ What Is mSQL in MySQL ⇐ Database Basics and Terminologies in MySQL ⇑ Database Basics and Terminologies in MySQL ⇑⇑ MySQL Database Tutorials 2017-07-21, 2615🔥, 0💬

What Is a Data Lock in MySQL
What Is a Data Lock in MySQL? MySQL uses two types of data locks at two levels to provide you the transaction isolation level you need: Share Lock at Row Level (S) - A data row is locked by a transaction for reading. Exclusive Lock at Row Level (X) - A data row is locked by a transaction for updatin... 2017-04-28, 2589🔥, 0💬

What Is a Dead Lock in MySQL
What Is a Dead Lock in MySQL? 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 (blo... 2017-04-28, 2517🔥, 0💬

Transaction Waiting for a Data Lock in MySQL
How Long a Transaction Will Wait for a Data Lock in MySQL? If you issue a UPDATE or DELETE statement on a row that has an exclusive lock owned by another session, your statement will be blocked to wait for the other session to release the lock. But the wait will be timed out after the predefined inn... 2017-04-28, 2472🔥, 0💬

Database Basics and Terminologies in MySQL
Where to find answers to frequently asked questions on Database Basics and Terminologies in MySQL? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Database Basics and Terminologies in MySQL to help you review your knowledge. A short answer is prov... 2017-07-21, 2467🔥, 0💬

Experiment with Data Locks in MySQL
How To Experiment Data Locks in MySQL? If you want to have some experience with data locks, you can create two windows running two mysql transactions in two sessions. In session 1, you can run a UPDATE statement with REPEATABLE READ transaction isolation level to create an exclusive lock. Before com... 2017-04-28, 2454🔥, 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.