30.4.3.21 The metrics View

This view summarizes MySQL server metrics to show variable names, values, types, and whether they are enabled. By default, rows are sorted by variable type and name.

The metrics view includes this information:

• Global status variables from the Performance Schema global_status table

• InnoDB metrics from the INFORMATION_SCHEMA INNODB_METRICS table

• Current and total memory allocation, based on the Performance Schema memory instrumentation

• The current time (human readable and Unix timestamp formats)

There is some duplication of information between the global_status and INNODB_METRICS tables, which the metrics view eliminates.

The metrics view has these columns:

• Variable_name

  The metric name. The metric type determines the source from which the name is taken:

  • For global status variables: The VARIABLE_NAME column of the global_status table

  • For InnoDB metrics: The NAME column of the INNODB_METRICS table

  • For other metrics: A view-provided descriptive string

• Variable_value

  The metric value. The metric type determines the source from which the value is taken:

  • For global status variables: The VARIABLE_VALUE column of the global_status table

  • For InnoDB metrics: The COUNT column of the INNODB_METRICS table

  • For memory metrics: The relevant column from the Performance Schema memory_summary_global_by_event_name table

  • For the current time: The value of NOW(3) or UNIX_TIMESTAMP(NOW(3))

• Type

  The metric type:

  • For global status variables: Global Status

  • For InnoDB metrics: InnoDB Metrics - %, where % is replaced by the value of the SUBSYSTEM column of the INNODB_METRICS table

  • For memory metrics: Performance Schema

  • For the current time: System Time

• Enabled

  Whether the metric is enabled:

  • For global status variables: YES

  • For InnoDB metrics: YES if the STATUS column of the INNODB_METRICS table is enabled, NO otherwise

  • For memory metrics: NO, YES, or PARTIAL (currently, PARTIAL occurs only for memory metrics and indicates that not all memory/% instruments are enabled; Performance Schema memory instruments are always enabled)

  • For the current time: YES