5.21 Optimizer Configuration Metrics

Lists the Optimizer configuration metrics and provides a brief description of each.

Table 5.20 Optimizer Configuration Metrics

NameDescription
End Markers In Json Enabled (Total)Whether optimizer JSON output should add end markers.
Eq Range Index Dive Limit (Total)Indicates the number of equality ranges in an equality comparison condition when the optimizer should switch from using index dives to index statistics in estimating the number of qualifying rows.
Max Length For Sort Data (Total)The maximum size of parameter values that can be sent with the mysql_stmt_send_long_data() C API function.
Max Seeks For Key (Total)Limit the assumed maximum number of seeks when looking up rows based on a key.
Max Sort Length (Total)The number of bytes to use when sorting data values. Only the first max_sort_length bytes of each value are used; the rest are ignored.
Prune Level Enabled (Total)Controls the heuristics applied during query optimization to prune less-promising partial plans from the optimizer search space.
Range Alloc Block Size (Total)The size of blocks (in bytes) that are allocated when doing range optimization.
Search Depth (Total)The maximum depth of search performed by the query optimizer.
Switch Value (Total)The optimizer_switch system variable enables control over optimizer behavior.
Trace (Total)Controls how to enable optimizer tracing.
Trace Features (Total)Enables or disables selected optimizer tracing features.
Trace Limit (Total)The maximum cumulative size of stored optimizer traces.
Trace Max Mem Size (Total)The maximum cumulative size of stored optimizer traces.
Trace Offset (Total)The offset of optimizer traces to display.