A hop connects one transformation step or job entry with another. The direction of the data flow is indicated by an arrow. To create the hop, click the source step, then press the SHIFT key and draw a line to the target step. Alternatively, you can draw hops by hovering over a step until the hover menu appears. Drag the hop painter icon from the source step to your target step.
Additional methods for creating hops include:
- Click on the source step, hold down the middle mouse button, and drag the hop to the target step.
- Use CTRL and left-click to select two steps the right-click on the step and choose New Hop.
To split a hop, insert a new step into the hop between two steps by dragging the step over a hop. Confirm that you want to split the hop. This feature works with steps that have not yet been connected to another step only.
Loops are not allowed in transformations because Spoon depends heavily on the previous steps to determine the field values that are passed from one step to another. Allowing loops in transformations may result in endless loops and other problems. Loops are allowed in jobs because Spoon executes job entries sequentially; however, make sure you do not create endless loops.
Mixing rows that have a different layout is not allowed in a transformation; for example, if you have two table input steps that use a varying number of fields. Mixing row layouts causes steps to fail because fields cannot be found where expected or the data type changes unexpectedly. The trap detector displays warnings at design time if a step is receiving mixed layouts.
You can specify if data can either be copied, distributed, or load balanced between multiple hops leaving a step. Select the step, right-click and choose Data Movement.
A hop can be enabled or disabled (for testing purposes for example). Right-click on the hop to display the Options menu.