Package com.pervasive.datarush.functions

Provides classes and interfaces related to defining functions on records.

See: Description

Package com.pervasive.datarush.functions Description

Provides classes and interfaces related to defining functions on records.

Many operators on records can be expressed as functions. These take a record from the input, perform some computation on the records, and emit a new record on the output. This can further be broken down into a sequence of functions producing each output field. These take values from one or more (or even no) fields from the record, and compute a single value representing the field's value.

Because functions encompass a much smaller range of functionality than do operators, they can generally be implemented much more quickly and easily. Functions, like operators, are composable - multiple functions can be combined to build more complex processing. Additionally, multiple functions can be applied to a record, yielding multiple values which can be appended or overlaid on the original records.

Due to this composability, functions enjoy some performance advantages over operators as they can combine the effects of several simple operators into one, reducing the total overhead related to the execution of operators. It should be noted that not all operators can be expressed as functions; only operators which produce one record of output per each record of input can be expressed in this way.

See Also:
DeriveFields, FilterRows, FieldCopier

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