It is a command to view the list of currently running processes. Example, it confirm that the batch is moving, or when get a heavy query.
Tha SQL that is being executed will be cut off in the middle of a line for info, and it should be displayed roughly.
mysql> show processlist;
| Id | User | Host | db | Command | Time | State | Info |
| 4 | root | localhost | NULL | Query | 0 | init | show processlist |
1 row in set (0.05 sec)