40.1. Sources of Diagnostic Information

When debugging applications, a database administrator can use the same methods for interpreting diagnostic information that any developer has access to, such as the SHOW WARNINGS and SHOW ERRORS statements, and the perror utility.

However, an administrator also has access to information that may not be available to developers, such as the contents of the error log and the slow query log. These logs normally are located in the data directory, which for security reasons should have restricted access.

This chapter focuses on those sources of information that are available only to administrators. Chapter 21, "Debugging MySQL Applications," covers the use of SHOW WARNINGS, SHOW ERRORS, and perror.