Remember (RapidMiner Studio Core)


This operator stores the given object in the object store of the process. The stored object can be retrieved from the store by using the Recall operator.


The Remember operator can be used to store the input object into the object store of the process under the specified name. The name of the object is specified through the name parameter. The io object parameter specifies the class of the object. The stored object can later be restored by the Recall operator by using the same name and class (i.e. the name and class that was used to store it using the Remember operator). There is no scoping mechanism in RapidMiner processes therefore objects can be stored (using Remember operator) and retrieved (using Recall operator) at any nesting level. But care should be taken that the execution order of operators is such that the Remember operator for an object always executes before the Recall operator for that object. The combination of these two operators can be used to build complex processes where an input object is used in completely different parts or loops of the processes.



The Remember operator is always used in combination with the Recall operator. The Remember operators stores the required object into the object store and the Recall operator retrieves the stored object when required.


  • store

    Any object can be provided here. This object will be stored in the object store of the process. It should be made sure that the class of this object is selected in the io object parameter.


  • stored

    The object that was given as input is passed without changing to the output through this port. It is not compulsory to attach this port to any other port, the object will be stored even if this port is left without connections.


  • nameThe name under which the input object is stored is specified through this parameter. The same name will be used for retrieving this object through the Recall operator. Range: string
  • io_objectThe class of the input object is selected through this parameter. Range: selection

Tutorial Processes

Introduction to Remember and Recall operators

This process uses the combination of the Remember and Recall operators to display the testing data set of the Split Validation operator. The testing data set is present in the testing subprocess of the Split Validation operator but it is not available outside the Split Validation operator.

The 'Golf' data set is loaded using the Retrieve operator. The Split Validation operator is applied on it. The test set size parameter is set to 5 and the training set size parameter is set to -1. Thus the test set in the testing subprocess will be composed of 5 examples. The Default Model operator is used in the training subprocess to train a model. The testing data set is available at the tes port of the testing subprocess. The Remember operator is used to store the testing data set into the object store of the process. The name and io object parameters are set to 'Testset' and 'ExampleSet' respectively. The Apply Model and Performance operator are applied in the testing subprocess later. In the main process, the Recall operator is used to retrieve the testing data set. The name and io object parameters of the Recall operator are set to 'Testset' and 'ExampleSet' respectively to retrieve the object that was stored by the Remember operator. The output of the Recall operator is connected to the result port of the process. Therefore the testing data set can be seen in the Results Workspace.