An information processor may include a command receiving unit that receives an immediate processing command in which a deletion target to be deleted from the database is conditioned, and a registration processing unit that registers information defining the deletion target into a management data unit. In addition, the information processor may include a deletion processing unit that deletes the deletion target from a database, and deregisters the deleted deletion target from the management data unit. The information processor can also include a data manipulation command processing unit, which, in the case where a data manipulation command having a manipulation target that coincides with a table of the deletion target registered in the management data unit is received, processes the data manipulation command in a state where a condition to exclude the deletion target from the manipulation target is added to the data manipulation command.