Constants can be entered either manually, or extracted from the input table. If the Input Port is connected, the constants generator extracts the attribute values of the data items in the given Column. If there is no input, a list of constants can be specified manually in the option panel.
Extracted constants can be used to filter data items. For example, if we extract the model.year values for a subset of cars, we can use those year constants to find the cars that were built in the same year(s).
Extracted constants can also be used to link two heterogeneous tables that share a key column. Please see Linking Heterogeneous Tables and Linkerfor more details.
Configures a column from which the attribute values are extracted. This can only be specified when the Input Port is connected.
Configures the constants generator to only extract distinct constant values.
Configures the constants generator to output the extracted constant values in sorted order.