10.15 Tracing the Optimizer

10.15.1 Typical Usage
10.15.2 System Variables Controlling Tracing
10.15.3 Traceable Statements
10.15.4 Tuning Trace Purging
10.15.5 Tracing Memory Usage
10.15.6 Privilege Checking
10.15.7 Interaction with the --debug Option
10.15.8 The optimizer_trace System Variable
10.15.9 The end_markers_in_json System Variable
10.15.10 Selecting Optimizer Features to Trace
10.15.11 Trace General Structure
10.15.12 Example
10.15.13 Displaying Traces in Other Applications
10.15.14 Preventing the Use of Optimizer Trace
10.15.15 Testing Optimizer Trace
10.15.16 Optimizer Trace Implementation

The MySQL optimizer includes the capability to perform tracing; the interface is provided by a set of optimizer_trace_xxx system variables and the INFORMATION_SCHEMA.OPTIMIZER_TRACE table.