As rollback can be 30 times slower than insert in InnoDB, and user may not know there's rollback (if it's because of a dupl row), better warn that it's happening. It can also be of use for a DBA killing a connection and wondering what this connection is still doing now. Example: |  5 | root | localhost | test | Killed  | 10   | Rolling back | insert into i select * from j |
As rollback can be 30 times slower than insert in InnoDB, and user may
not know there's rollback (if it's because of a dupl row), better warn
that it's happening. It can also be of use for a DBA killing a
connection and wondering what this connection is still doing now. Example:
|  5 | root | localhost | test | Killed  | 10   | Rolling back | insert into i select * from j |


sql/handler.cc:
  As rollback can be 30 times slower than insert in InnoDB, and user may
  not know there's rollback (if it's because of a dupl row), better warn.

flynn1973/mariadb-aix,ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,ollie314/server,ollie314/server,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,slanterns/server,ollie314/server,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,flynn1973/mariadb-aix,ollie314/server,ollie314/server,davidl-zend/zenddbi