在数据库启动时，MySQL 会怎么处理这个被中断的 delete 操作? assume it's INNODB. Mysql will start crash recovery processes, apply redo, do un-commit transaction rollback. Since this huge delete is not commit, mysql has to rollback it. Until all rollback finished, mysql can accept application traffic. so this guy might need to wait for long time while mysql is un-available. But i think in concept, once mysql finish redo apply in crash-recovery phase, it should be able to accept traffic while rollback un-commit transaction is still in-progress; application query can still wait for lock or do MVCC read. not sure if there're some internal parameter control it.