What Is a Dead Lock

Q

What Is a Dead Lock? - MySQL FAQs - Transaction Management: Commit or Rollback

✍: 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)

2007-05-09, 5742👍, 0💬

How To Test Transaction Isolation Levels
How To Test Transaction Isolation Levels? - MySQL FAQs - Transaction Management: Commit or Rollback If you want to test transaction isolation levels, you need to make sure that: The tables are created with transaction-safe storage engines, like InnoDB. Multiple-statement transactions are started wit... 2007-05-09, 7181👍, 0💬

What Happens to Your Transactions When ERROR 1205 Occurred
What Happens to Your Transactions When ERROR 1205 Occurred? - MySQL FAQs - Transaction Management: Commit or Rollback 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 tran... 2007-05-11, 6329👍, 0💬

How Long a Transaction Will Wait for a Data Lock
How Long a Transaction Will Wait for a Data Lock? - MySQL FAQs - Transaction Management: Commit or Rollback 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 th... 2007-05-11, 5866👍, 0💬

What Is CSS (Cascading Style Sheets)
What Is CSS (Cascading Style Sheets)? - CSS Tutorials - Introduction To CSS Basics CSS (Cascading Style Sheets) is a technical specification that allows HTML document authors to attach formatting style sheets to HTML documents. When HTML documents are viewed as Web pages through Web browsers, the at... 2007-05-11, 5811👍, 0💬

What Is a Dead Lock
What Is a Dead Lock? - MySQL FAQs - Transaction Management: Commit or Rollback 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 ... 2007-05-09, 5743👍, 0💬

How To Experiment Data Locks
How To Experiment Data Locks? - MySQL FAQs - Transaction Management: Commit or Rollback 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 isolat... 2007-05-11, 5703👍, 0💬

How To Experiment Dead Locks
How To Experiment Dead Locks? - MySQL FAQs - Transaction Management: Commit or Rollback If you want to have some experience with dead locks, you can create two windows running two mysql transactions in two sessions at the REPEATABLE READ transaction isolation level. Then run some UPDATE statements a... 2007-05-09, 5388👍, 0💬

What Are the Impacts on Applications from Locks, Timeouts, and DeadLocks
What Are the Impacts on Applications from Locks, Timeouts, and DeadLocks? - MySQL FAQs - Transaction Management: Commit or Rollback 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 d... 2007-05-08, 5363👍, 0💬

What Is a Data Lock
What Is a Data Lock? - MySQL FAQs - Transaction Management: Commit or Rollback 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) - ... 2007-05-09, 5261👍, 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.