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## CrossJoin

# Available in Community Designer

Short Description
Ports
Metadata
CrossJoin Attributes
Details
Examples
Best Practices
Compatibility
See also

### Short Description

CrossJoin creates a Cartesian product of records from connected input ports.

Component | Same input metadata | Sorted inputs | Slave inputs | Outputs | Output for driver without slave | Output for slaves without driver | Joining based on equality | Auto-propagated metadata
--- | --- | --- | --- | --- | --- | --- | --- | ---
CrossJoin |  |  | 0-n | 1 |  |  |  |

### Icon

### Ports

Port type | Number | Required | Description | Metadata
--- | --- | --- | --- | ---
Input | 0 |  | Master input port | Any1
1-n |  | 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

Attribute | Req | Description | Possible values
--- | --- | --- | ---
Advanced
Transform | [1] | Transformation in CTL or Java defined in the graph. |
Transform URL | [1] | External file defining the transformation in CTL or Java. |
Transform class | [1] | External transformation class. |
Transform source charset |  | Encoding of 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:

    Brown
    Smith
    Jones

Goods:

    Pineapple
    Turnip
    Spaceship

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

    Brown|Pineapple
    Brown|Turnip
    Brown|Spaceship
    Smith|Pineapple
    Smith|Turnip
    Smith|Spaceship
    Jones|Pineapple
    Jones|Turnip
    Jones|Spaceship

### 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.

### Compatibility

#### 4.1.0-M1

CrossJoin component is available since CloverETL 4.1.0-M1.

### See also

Common Properties of Components
Specific Attribute Types
Common Properties of Transformers
Joiners Comparison

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