Server Tracking of Client Session State Changes Preceding the  START TRANSACTION  statement, two  SET TRANSACTION  statements execute that set the isolation level and access mode characteristics for the next transaction. The SESSION_TRACK_TRANSACTION_CHARACTERISTICS  value indicates those next-transaction values that have been set. Following the  COMMIT  statement that ends the transaction, the SESSION_TRACK_TRANSACTION_CHARACTERISTICS  value is reported as empty. This indicates that the 1013 -- utf8mb4 -- character_set_results -- utf8mb4 -- Tracker : SESSION_TRACK_STATE_CHANGE -- 1 SET @@SESSION.session_track_transaction_info=’CHARACTERISTICS’; -- Tracker : SESSION_TRACK_SYSTEM_VARIABLES -- session_track_transaction_info -- CHARACTERISTICS -- Tracker : SESSION_TRACK_STATE_CHANGE -- 1 -- Tracker : SESSION_TRACK_TRANSACTION_CHARACTERISTICS -- -- Tracker : SESSION_TRACK_TRANSACTION_STATE -- ________ SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; -- Tracker : SESSION_TRACK_TRANSACTION_CHARACTERISTICS -- SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; SET TRANSACTION READ WRITE; -- Tracker : SESSION_TRACK_TRANSACTION_CHARACTERISTICS -- SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; SET TRANSACTION READ WRITE; START TRANSACTION; -- Tracker : SESSION_TRACK_TRANSACTION_CHARACTERISTICS -- SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; START TRANSACTION READ WRITE; -- Tracker : SESSION_TRACK_TRANSACTION_STATE -- T_______ SELECT 1; 1 1 -- Tracker : SESSION_TRACK_TRANSACTION_STATE -- T_____S_ INSERT INTO test.t1 () VALUES(); -- Tracker : SESSION_TRACK_TRANSACTION_STATE -- T___W_S_ INSERT INTO test.t1 () VALUES(1, RAND()); -- Tracker : SESSION_TRACK_TRANSACTION_STATE -- T___WsS_ COMMIT; -- Tracker : SESSION_TRACK_TRANSACTION_CHARACTERISTICS -- -- Tracker : SESSION_TRACK_TRANSACTION_STATE -- ________ ok