SELECT SOURCE_POS_WAIT('source_log_file', source_log_pos [, timeout][, channel])

This is actually a function, not a statement. It is used to ensure that the replica has read and executed events up to a given position in the source's binary log. See Section 12.24, “Miscellaneous Functions”, for a full description.

From MySQL 8.0.26, use SOURCE_POS_WAIT in place of MASTER_POS_WAIT, which is deprecated from that release. In releases before MySQL 8.0.26, use MASTER_POS_WAIT.