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## 26.4.22 The INFORMATION_SCHEMA INNODB_LOCK_WAITS Table 

The INNODB_LOCK_WAITS  table contains one or more rows for each blocked InnoDB  transaction, indicating the lock it has requested and any locks that are blocking that request. 

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## Note 

This table is deprecated and is removed as of MySQL 8.0.1. Use the Performance Schema data_lock_waits  table instead. See Section 27.12.13.2, “The data_lock_waits Table” . 

The tables differ in the privileges required: The INNODB_LOCK_WAITS  table requires the global PROCESS  privilege. The data_lock_waits  table requires the usual Performance Schema privilege of SELECT  on the table to be selected from. 

The following table shows the mapping from INNODB_LOCK_WAITS  columns to data_lock_waits columns. Use this information to migrate applications from one table to the other. 

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## 26.4.23 The INFORMATION_SCHEMA INNODB_METRICS Table 

The INNODB_METRICS  table provides a wide variety of InnoDB  performance information, complementing the specific focus areas of the Performance Schema tables for InnoDB . With simple queries, you can check the overall health of the system. With more detailed queries, you can diagnose issues such as performance bottlenecks, resource shortages, and application issues. 

Each monitor represents a point within the InnoDB  source code that is instrumented to gather counter information. Each counter can be started, stopped, and reset. You can also perform these actions for a group of counters using their common module name. 

By default, relatively little data is collected. To start, stop, and reset counters, set one of the system variables innodb_monitor_enable , innodb_monitor_disable , innodb_monitor_reset , or innodb_monitor_reset_all , using the name of the counter, the name of the module, a wildcard match for such a name using the “%”  character, or the special keyword all . 

For usage information, see Section 15.15.6, “InnoDB INFORMATION_SCHEMA Metrics Table” . 

The INNODB_METRICS  table has these columns: 

• NAME 

A unique name for the counter. 

• SUBSYSTEM 

