{aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee} 

For the meanings of fields within the value, see the UUID()  function description. 

mysql> SELECT IS_UUID(’6ccd780c-baba-1026-9564-5b8c656024db’); +-------------------------------------------------+ | IS_UUID(’6ccd780c-baba-1026-9564-5b8c656024db’) | +-------------------------------------------------+ | 1 | +-------------------------------------------------+ mysql> SELECT IS_UUID(’6CCD780C-BABA-1026-9564-5B8C656024DB’); +-------------------------------------------------+ | IS_UUID(’6CCD780C-BABA-1026-9564-5B8C656024DB’) | +-------------------------------------------------+ | 1 | +-------------------------------------------------+ mysql> SELECT IS_UUID(’6ccd780cbaba102695645b8c656024db’); +---------------------------------------------+ | IS_UUID(’6ccd780cbaba102695645b8c656024db’) | +---------------------------------------------+ | 1 | +---------------------------------------------+ mysql> SELECT IS_UUID(’{6ccd780c-baba-1026-9564-5b8c656024db}’); +---------------------------------------------------+ | IS_UUID(’{6ccd780c-baba-1026-9564-5b8c656024db}’) | +---------------------------------------------------+ | 1 | +---------------------------------------------------+ mysql> SELECT IS_UUID(’6ccd780c-baba-1026-9564-5b8c6560’); +---------------------------------------------+ | IS_UUID(’6ccd780c-baba-1026-9564-5b8c6560’) | +---------------------------------------------+ | 0 | +---------------------------------------------+ mysql> SELECT IS_UUID(RAND()); +-----------------+ | IS_UUID(RAND()) | +-----------------+ | 0 | +-----------------+ 

• MASTER_POS_WAIT( log_name , log_pos [, timeout ][, channel ]) 

This function is useful for control of source/replica synchronization. It blocks until the replica has read and applied all updates up to the specified position in the source’s binary log. The return value is the number of log events the replica had to wait for to advance to the specified position. The function returns NULL  if the replication SQL thread is not started, the replica’s source information is not initialized, the arguments are incorrect, or an error occurs. It returns -1  if the timeout has been exceeded. If the replication SQL thread stops while MASTER_POS_WAIT()  is waiting, the function returns NULL . If the replica is past the specified position, the function returns immediately. 

On a multithreaded replica, the function waits until expiry of the limit set by the slave_checkpoint_group  or slave_checkpoint_period  system variable, when the checkpoint 

