InnoDB INFORMATION_SCHEMA Transaction and Locking Information Correlating InnoDB Transactions with MySQL Sessions Sometimes it is useful to correlate internal  InnoDB  locking information with the session-level information maintained by MySQL. For example, you might like to know, for a given  InnoDB  transaction ID, the corresponding MySQL session ID and name of the session that may be holding a lock, and thus blocking other transactions. The following output from the  INFORMATION_SCHEMA INNODB_TRX  table and Performance Schema data_locks  and  data_lock_waits  tables is taken from a somewhat loaded system. As can be seen, there are several transactions running. The following  data_locks  and  data_lock_waits  tables show that: •Transaction  77F  (executing an  INSERT ) is waiting for transactions  77E ,  77D , and  77B  to commit. •Transaction  77E  (executing an  INSERT ) is waiting for transactions  77D  and  77B  to commit. •Transaction  77D  (executing an  INSERT ) is waiting for transaction  77B  to commit. •Transaction  77B  (executing an  INSERT ) is waiting for transaction  77A  to commit. •Transaction  77A  is running, currently executing  SELECT . •Transaction  E56  (executing an  INSERT ) is waiting for transaction  E55  to commit. •Transaction  E55  (executing an  INSERT ) is waiting for transaction  19C  to commit. •Transaction  19C  is running, currently executing an  INSERT . Note There may be inconsistencies between queries shown in the INFORMATION_SCHEMA PROCESSLIST  and  INNODB_TRX  tables. For an explanation, see Section 15.15.2.3, “Persistence and Consistency of InnoDB Transaction and Locking Information” . The following table shows the contents of the  PROCESSLIST  table for a system running a heavy workload. ID USER HOST DB COMMAND TIME STATE INFO 384 root localhost test Query 10 update INSERT INTO t2 VALUES … 257 root localhost test Query 3 update INSERT INTO t2 VALUES … 130 root localhost test Query 0 update INSERT INTO t2 VALUES … 61 root localhost test Query 1 update INSERT INTO t2 VALUES … 8 root localhost test Query 1 update INSERT INTO t2 VALUES … 3304