Appendix B Error Messages and Common Problems Table of Contents Additional Resources B.1 Error Message Sources and Elements Error Message Sources B.1 Error Message Sources and Elements ..................................................................................... 5281 B.2 Error Information Interfaces ..................................................................................................... 5283 B.3 Problems and Common Errors ................................................................................................ 5285 B.3.1 How to Determine What Is Causing a Problem .............................................................. 5285 B.3.2 Common Errors When Using MySQL Programs ............................................................ 5287 B.3.3 Administration-Related Issues ....................................................................................... 5298 B.3.4 Query-Related Issues .................................................................................................. 5306 B.3.5 Optimizer-Related Issues ............................................................................................. 5313 B.3.6 Table Definition-Related Issues .................................................................................... 5314 B.3.7 Known Issues in MySQL .............................................................................................. 5315 This appendix describes the types of error information MySQL provides and how to obtain information about them. The final section is for troubleshooting. It describes common problems and errors that may occur and potential resolutions. Other error-related documentation includes: Error messages can originate on the server side or the client side: This section discusses how error messages originate within MySQL and the elements they contain. •Information about configuring where and how the server writes the error log: Section 5.4.2, “The Error Log” •Information about the character set used for error messages: Section 10.6, “Error Message Character Set” •Information about the language used for error messages: Section 10.12, “Setting the Error Message Language” •Information about errors related to  InnoDB : Section 15.21.4, “InnoDB Error Handling” •Descriptions of the error messages that the MySQL server and client programs generate: MySQL 8.0 Error Message Reference •Error Message Sources •Error Message Elements •Error Code Ranges •On the server side, error messages may occur during the startup and shutdown processes, as a result of issues that occur during SQL statement execution, and so forth. •The MySQL server writes some error messages to its error log. These indicate issues of interest to database administrators or that require DBA action. 5281