Transaction Isolation Levels

This section describes 4 transaction isolation levels: Read Uncommitted, Read Committed, Repeatable Read, Serializable.

As we can see from previous sections, the impact of a transaction in the current session is simple. However, concurrent transactions in multiple sessions may impact each other in many ways. Three phenomena have been observed in concurrent transactions:

To be able to control and avoid those phenomena, 4 transaction isolation levels have been defined by SQL standards:

MySQL support of transaction Isolation levels:

Last update: 2015.

Table of Contents

 About This Book

 Introduction of SQL

 MySQL Introduction and Installation

 Introduction of MySQL Programs

 Perl Programs and MySQL Servers

 PHP Programs and MySQL Servers

 Java Programs and MySQL Servers

 Datatypes and Data Literals

 Operations and Expressions

 Character Strings and Bit Strings

 Commonly Used Functions

 Table Column Types for Different Types of Values

 Using DDL to Create Tables and Indexes

 Using DML to Insert, Update and Delete Records

 Using SELECT to Query Database

Transaction Management and Isolation Levels

 What Is a Transaction?

 Transaction Management in MySQL

Transaction Isolation Levels

 "Read Uncommitted" Isolation Level

 "Read Committed" Isolation Level

 "Repeatable Read" Isolation Level

 Locks Used in MySQL

 Defining and Calling Stored Procedures

 Variables, Loops and Cursors Used in Stored Procedures

 Outdated Tutorials


 PDF Printing Version