How To View and Change the Current Transaction Isolation Level

Q

How To View and Change the Current Transaction Isolation Level? - MySQL FAQs - Transaction Management: Commit or Rollback

✍: FYIcenter.com

A

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 levelName; -- Changing the current transaction isolation level.

The tutorial exercise below shows you how to view and change transaction isolation level:

>\mysql\bin\mysql -u dev -piyf fyi

mysql> SELECT @@TX_ISOLATION FROM DUAL;
+-----------------+
| @@TX_ISOLATION  |
+-----------------+
| REPEATABLE-READ |
+-----------------+
1 row in set (0.46 sec)

mysql> SET TRANSACTION ISOLATION LEVEL READ COMMITTED;
Query OK, 0 rows affected (0.10 sec)

mysql> SELECT @@TX_ISOLATION FROM DUAL;
+----------------+
| @@TX_ISOLATION |
+----------------+
| READ-COMMITTED |
+----------------+
1 row in set (0.02 sec)

2007-05-11, 5539👍, 0💬

What Happens to the Current Transaction If a DDL Statement Is Executed
What Happens to the Current Transaction If a DDL Statement Is Executed? - MySQL FAQs - Transaction Management: Commit or Rollback If a DDL statement is executed, the current transaction will be committed and ended. All the database changes made in the current transaction will become permanent. This ... 2007-05-11, 6288👍, 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, 6204👍, 0💬

How Does MySQL Handle Read Consistency
How Does MySQL Handle Read Consistency? - MySQL FAQs - Transaction Management: Commit or Rollback Read consistency is a concept that describes how consistent the output will be on two subsequent read operations. A read operation is usually a stand alone SELECT statement or a SELECT subquery in a par... 2007-05-11, 5798👍, 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, 5753👍, 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, 5584👍, 0💬

How To View and Change the Current Transaction Isolation Level
How To View and Change the Current Transaction Isolation Level? - MySQL FAQs - Transaction Management: Commit or Rollback 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 iso... 2007-05-11, 5540👍, 0💬

What Happens to the Current Transaction If the Session Is Killed
What Happens to the Current Transaction If the Session Is Killed? - MySQL FAQs - Transaction Management: Commit or Rollback If a session is killed by the DBA, the current transaction in that session will be rolled back and ended. All the database changes made in the current transaction will be remov... 2007-05-11, 5433👍, 0💬

What Are Transaction Isolation Levels
What Are Transaction Isolation Levels? - MySQL FAQs - Transaction Management: Commit or Rollback There are 4 transaction isolation levels defined by SQL-1992 standard: READ UNCOMMITTED - The SELECT statements in one transaction will read uncommitted data changes from transactions of all connected se... 2007-05-09, 5260👍, 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, 5161👍, 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.