Concatenate receives unsorted data records from multiple inputs.

It gathers input records starting with the first input port, continuing with the next one and ending with the last port. Within each input port, the records order is preserved.

Component	Same input metadata	Sorted inputs	Inputs	Outputs	Java	CTL	Auto-propagated metadata
Concatenate			1-n	1	-	-

Port type	Number	Required	Description	Metadata
Input	0		For input data records	Any
	1-n		For input data records	Input 0
Output	0		For gathered data records	Input 0

At least one input port has to be connected. Any other input port can be disabled (changed in 4.1.0-M1).

Metadata can be propagated through this component.

Metadata of all input ports must be the same.

First, the component receives all of the records incoming through the first input port, sends all of them to the common output port and, subsequently, adds to them all of the records incoming through the next input port. If the component has more than two input ports, the records are received and sent to the output according to the order of the input ports.

If some of the input ports contain no records, such port is skipped.