Append streams

Description

The "Append streams" step reads the data from two steps, only processing the second stream after the first is finished.
As always, the row layout for the input data coming from both steps has to be identical: the same row lengths, the same data types, the same fields at the same field indexes in the row.

Important: If you don't care about the order in which the output rows occur, you can use any step to create a union of 2 or more data streams.

Options

Option

Description

Step name

Name of the step. Note: This name has to be unique in a single transformation.

Head hop

The name of the step from which will be read from first.

Tail hop

The name of the step from which will be read from last.

Example

An example showing the basic functionality is available in your Kettle distribution under this name:

samples/transformations/Append streams - Basic example.ktr

Metadata Injection Support (7.x and later)

All fields of this step support metadata injection. You can use this step with ETL Metadata Injection to pass metadata to your transformation at runtime.