MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
          The cond_instances table lists
          all the conditions seen by the Performance Schema while the
          server executes. A condition is a synchronization mechanism
          used in the code to signal that a specific event has happened,
          so that a thread waiting for this condition can resume work.
        
When a thread is waiting for something to happen, the condition name is an indication of what the thread is waiting for, but there is no immediate way to tell which other threads cause the condition to happen.
          The cond_instances table has
          these columns:
        
              NAME
            
The instrument name associated with the condition.
              OBJECT_INSTANCE_BEGIN
            
The address in memory of the instrumented condition.
          TRUNCATE TABLE is not permitted
          for the cond_instances table.