CrossJoin
Short Description
CrossJoin creates a Cartesian product of records from connected input ports.
CrossJoin
x
x
0-n
1
x
x
x
✓
Ports
Input
0
✓
Master input port
Any1
1-n
x
Slave input port(s)
Any2
Output
0
✓
For output data records
Any3
Metadata
CrossJoin automatically generates metadata on the output port from metadata on its input ports. The generated metadata can be seen as a dynamic template.
CrossJoin Attributes
Transform
[1]
A transformation in CTL or Java defined in the graph.
Transform URL
[1]
An external file defining the transformation in CTL or Java.
Transform class
[1]
An external transformation class.
Transform source charset
Encoding of an external file defining the transformation.
E.g. UTF-8
[1] At most one of these attributes can be set.
Details
CrossJoin creates a Cartesian product of input records.
It works in the following way: the component takes the first record from the first port, the first record from the second port (…​) and the first record from the last port and generates the output record. Subsequently, it takes the first record from the first port, the first record from the second port (…​) and the second record from the last port. It continues with the third record from the last input port and so on.
Processing Large Number of Records If you process a very large number of records, temporary files with the swapped records may be created on your hard drive. This prevents excessive memory usage.
Examples
Simple CrossJoin Example Given a list of customers and a list of products of "All on the Store Ltd." Customers:
Goods:
Create a list containing all possibilities.
Solution You only need to connect sources of data with **CrossJoin **component. No setup of attributes of the component is necessary. The result is:
Best Practices
The edge giving the most records should be connected to the first input port. If the transformation is specified in an external file (with Transform URL), we recommend users to explicitly specify Transform source charset.