Server System Variables The transaction completion type. This variable can take the values shown in the following table. The variable can be assigned using either the name values or corresponding integer values. 2 Value Description NO_CHAIN  (or 0) COMMIT  and  ROLLBACK  are unaffected. This is the default value. CHAIN  (or 1) COMMIT  and  ROLLBACK  are equivalent to  COMMIT AND CHAIN  and  ROLLBACK AND CHAIN , respectively. (A new transaction starts immediately with the same isolation level as the just-terminated transaction.) RELEASE  (or 2) COMMIT  and  ROLLBACK  are equivalent to  COMMIT RELEASE  and  ROLLBACK RELEASE , respectively. (The server disconnects after terminating the transaction.) completion_type  affects transactions that begin with  START TRANSACTION  or  BEGIN  and end with COMMIT  or  ROLLBACK . It does not apply to implicit commits resulting from execution of the statements listed in Section 13.3.3, “Statements That Cause an Implicit Commit” . It also does not apply for  XA COMMIT ,  XA ROLLBACK , or when  autocommit=1 . • concurrent_insert Command-Line Format --concurrent-insert[=value] System Variable concurrent_insert Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Enumeration Default Value AUTO Valid Values NEVER AUTO ALWAYS 0 1 783