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•Information from other relevant sys  schema views, such as the one that detemines queries in the 95th percentile 

•Information from the ndbinfo  schema, if the MySQL server is part of NDB Cluster 

•Replication status (both source and replica) 

Some of the sys schema views are calculated as initial (optional), overall, and delta values: 

•The initial view is the content of the view at the start of the diagnostics()  procedure. This output is the same as the start values used for the delta view. The initial view is included if the diagnostics.include_raw  configuration option is ON . 

•The overall view is the content of the view at the end of the diagnostics()  procedure. This output is the same as the end values used for the delta view. The overall view is always included. 

•The delta view is the difference from the beginning to the end of procedure execution. The minimum and maximum values are the minimum and maximum values from the end view, respectively. They do not necessarily reflect the minimum and maximum values in the monitored period. Except for the metrics view, the delta is calculated only between the first and last outputs. 

## Parameters 

• in_max_runtime INT UNSIGNED : The maximum data collection time in seconds. Use NULL  to collect data for the default of 60 seconds. Otherwise, use a value greater than 0. 

• in_interval INT UNSIGNED : The sleep time between data collections in seconds. Use NULL  to sleep for the default of 30 seconds. Otherwise, use a value greater than 0. 

• in_auto_config ENUM(’current’, ’medium’, ’full’) : The Performance Schema configuration to use. Permitted values are: 

• current : Use the current instrument and consumer settings. 

• medium : Enable some instruments and consumers. 

• full : Enable all instruments and consumers. 

<img src='content_image/855238.jpg'>

Use of the medium  or full  setting requires the SUPER  privilege. 

## Note 

The more instruments and consumers enabled, the more impact on MySQL server performance. Be careful with the medium  setting and especially the full setting, which has a large performance impact. 

If a setting other than current  is chosen, the current settings are restored at the end of the procedure. 

## Configuration Options 

diagnostics()  operation can be modified using the following configuration options or their corresponding user-defined variables (see Section 28.4.2.1, “The sys_config Table” ): 

• debug , @sys.debug 

If this option is ON , produce debugging output. The default is OFF . 

• diagnostics.allow_i_s_tables , @sys.diagnostics.allow_i_s_tables 

