tMap Standard properties

Map editor

It allows you to define the tMap routing and transformation properties.

If needed, click the button at the top of the input area to open the Property Settings dialog box, which provides the following options:

• Die on error: Select this check box if you want to kill the Job if there is an error. This check box is selected by default.

• Lookup in parallel: Select this check to maximize the data transformation performance in a Job that handles multiple lookup input flows with large amounts of data.

• Enable Auto-Conversion of types: If your input and output columns across a mapping are of different data types, select this check box to enable automatic type conversion at the run time to avoid compiling errors.

  This option is enabled by default if the Enable Auto-Conversion of types check box is selected in the Project Settings view when this component is added. You can also override the default conversion behavior of this component by setting conversion rules in the Project Settings view. For more information, see Talend Studio User Guide.

  Note that auto conversion between Date and BigDecimal is not supported.

• Store on disk: The options provided in this area are identical to the relevant options provided on the Basic settings and Advanced settings tabs respectively. Settings made in the Property Settings dialog box are reflected in the respective tab views and vice versa.

This component offers the advantage of the dynamic schema feature. This allows you to retrieve unknown columns from source files or to copy batches of columns from a source without mapping each column individually. For further information about dynamic schemas, see Talend Studio User Guide.

This dynamic schema feature is designed for the purpose of retrieving unknown columns of a table and is recommended to be used for this purpose only; it is not recommended for the use of creating tables.

Mapping links display as

Auto: the default setting is curves links

Curves: the mapping display as curves

Lines: the mapping displays as straight lines. This last option allows to slightly enhance performance.

Preview

The preview is an instant shot of the Mapper data. It becomes available when Mapper properties have been filled in with data. The preview synchronization takes effect only after saving changes.

tStatCatcher Statistics

Select this check box to gather the Job processing metadata at the Job level as well as at each component level.

Global Variables

ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box.

A Flow variable functions during the execution of a component while an After variable functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl + Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio User Guide.

Usage rule

Possible uses are from a simple reorganization of fields to the most complex Jobs of data multiplexing or demultiplexing transformation, concatenation, inversion, filtering and more...

Limitation

The use of tMap supposes minimum Java knowledge in order to fully exploit its functionalities.

This component is a junction step, and for this reason cannot be a start nor end component in the Job.