Performance Schema Thread Pool Tables • STALLED_THREAD_COUNT • WAITING_THREAD_NUMBER • OLDEST_QUEUED • MAX_THREAD_IDS_IN_GROUP •Unique index on ( TP_GROUP_ID ) • TP_GROUP_ID • CONNECTIONS_STARTED • CONNECTIONS_CLOSED • QUERIES_EXECUTED 5039 The number of connections closed. The number of connections started. The thread group ID. This is a unique key within the table. The  tp_thread_group_stats  table has these columns: The  tp_thread_group_stats  table reports statistics per thread group. There is one row per group. The Performance Schema table described here is available as of MySQL 8.0.14. Prior to MySQL 8.0.14, use the corresponding  INFORMATION_SCHEMA table instead; see Section 26.5.3, “The INFORMATION_SCHEMA TP_THREAD_GROUP_STATS Table” . TRUNCATE TABLE  is not permitted for the  tp_thread_group_state  table. The  tp_thread_group_state  table has these indexes: The maximum thread ID of the threads in the group. This is the same as  MAX(TP_THREAD_NUMBER)  for the threads when selected from the  tp_thread_state  table. That is, these two queries are equivalent: How long in milliseconds the oldest queued statement has been waiting for execution. If there is a thread handling the polling of statements in the thread group, this specifies the thread number within this thread group. It is possible that this thread could be executing a statement. The number of stalled statements in the thread group. A stalled statement could be executing, but from a thread pool perspective it is stalled and making no progress. A long-running statement quickly ends up in this category. SELECT TP_GROUP_ID, MAX_THREAD_IDS_IN_GROUP FROM tp_thread_group_state; SELECT TP_GROUP_ID, MAX(TP_THREAD_NUMBER) FROM tp_thread_state GROUP BY TP_GROUP_ID; 27.12.16.2 The tp_thread_group_stats Table Note