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Oracle Enterprise Manager for MySQL Database User's Guide
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7.24 Optimizer Configuration Metrics

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

Table 7.24 Optimizer Configuration Metrics

NameDescription
End Markers In Json EnabledWhether optimizer JSON output adds end markers.
Eq Range Index Dive LimitIndicates the number of equality ranges in an equality comparison condition when the optimizer switches from using index dives to index statistics in estimating the number of qualifying rows.
Histogram Generation Max Mem SizeThe maximum amount of memory available for generating histogram statistics.
Max Length For Sort DataThe maximum size of parameter values that can be sent with the mysql_stmt_send_long_data() C API function.
Max Seeks For KeyLimit the assumed maximum number of seeks when looking up rows based on a key.
Max Sort LengthThe 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 EnabledControls the heuristics applied during query optimization to prune less-promising partial plans from the optimizer search space.
Range Alloc Block SizeThe size of blocks (in bytes) that are allocated when doing range optimization.
Search DepthThe maximum depth of search performed by the query optimizer.
Switch ValueThe optimizer_switch system variable enables control over optimizer behavior.
TraceControls how to enable optimizer tracing.
Trace FeaturesEnables or disables selected optimizer tracing features.
Trace LimitThe maximum cumulative size of stored optimizer traces.
Trace Max Mem SizeThe maximum cumulative size of stored optimizer traces.
Trace OffsetThe offset of optimizer traces to display.
Windowing Use High Precision EnabledWhether to compute window operations without loss of precision. Default is ON.