sys Schema Views • table_schema • table_name • index_name • non_unique • subpart_exists • index_columns • object_schema • object_name • waiting_thread_id • waiting_pid • waiting_account • waiting_lock_type • waiting_lock_duration The schema that contains the table. The table that contains the index. An index name. The number of nonunique columns in the index. Whether the index indexes only part of a column. The name of the columns in the index. These views display which sessions are blocked waiting on metadata locks, and what is blocking them. The column descriptions here are brief. For additional information, see the description of the Performance Schema  metadata_locks  table at Section 27.12.13.3, “The metadata_locks Table” . The  schema_table_lock_waits  and  x$schema_table_lock_waits  views have these columns: The schema containing the object to be locked. The name of the instrumented object. The thread ID of the thread that is waiting for the lock. The processlist ID of the thread that is waiting for the lock. The account associated with the session that is waiting for the lock. The type of the waiting lock. How long the waiting lock has been waiting. 28.4.3.28 The schema_table_lock_waits and x$schema_table_lock_waits Views 5163