tTeradataSCD - 6.3

Talend Open Studio for Big Data Components Reference Guide

EnrichVersion
6.3
EnrichProdName
Talend Open Studio for Big Data
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Function

This component reflects and tracks changes in a dedicated Teradata SCD table.

Purpose

This component addresses Slowly Changing Dimension needs, reading regularly a source of data and logging the changes into a dedicated SCD table.

tTeradataSCD Properties

Component Family

Databases/Teradata

Basic settings

Property Type

Either Built-In or Repository.

Since version 5.6, both the Built-In mode and the Repository mode are available in any of the Talend solutions.

 

 

Built-In: No property data stored centrally.

 

 

Repository: Select the repository file in which the properties are stored. The database connection related fields that follow are completed automatically using the data retrieved.

 

Use an existing connection

Select this check box and in the Component List click the relevant connection component to reuse the connection details you already defined.

Note

When a Job contains the parent Job and the child Job, if you need to share an existing connection between the two levels, for example, to share the connection created by the parent Job with the child Job, you have to:

  1. In the parent level, register the database connection to be shared in the Basic settings view of the connection component which creates that very database connection.

  2. In the child level, use a dedicated connection component to read that registered database connection.

For an example about how to share a database connection across Job levels, see Talend Studio User Guide.

 

Host

Type in the IP address or hostname of the database.

 

Database

Type in the name of the database you want to use.

 

Username and Password

Type in the database user authentication data.

To enter the password, click the [...] button next to the password field, and then in the pop-up dialog box enter the password between double quotes and click OK to save the settings.

 

Table

Type in the name of the table to be written. Note that only one table can be written at a time.

 

Action on table

On the table defined, you can perform one of the following operations:

  • None: No operation is carried out.

  • Create table: The table does not exist and gets created.

  • Create table if not exists: The table is created if it does not exist.

 

Schema and Edit schema

A schema is a row description. It defines the number of fields (columns) to be processed and passed on to the next component. The schema is either Built-In or stored remotely in the Repository.

Since version 5.6, both the Built-In mode and the Repository mode are available in any of the Talend solutions.

 

 

Built-In: You create and store the schema locally for this component only. Related topic: see Talend Studio User Guide.

 

 

Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs. Related topic: see Talend Studio User Guide.

 

 

Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available:

  • View schema: choose this option to view the schema only.

  • Change to built-in property: choose this option to change the schema to Built-in for local changes.

  • Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the [Repository Content] window.

 

SCD Editor

The SCD editor helps to build and configure the data flow for slowly changing dimension outputs.

For more information, see SCD management methodologies.

 

Use memory saving mode

Select this check box to maximize system performance.

 

Source keys include Null

Select this check box to allow the source key columns to have Null values.

Warning

Special attention should be paid to the uniqueness of the source key(s) values when this option is selected.

 

Die on error

Select this check box to stop the execution of the Job when an error occurs.

Clear the check box to skip any rows on error and complete the process for error-free rows. When errors are skipped, you can collect the rows on error using a Row > Reject link.

Advanced settings

Additional JDBC Parameters

Specify additional connection properties for the database connection you are creating.

This field is not visible when the Use an existing connection check box is selected.

 

Debug mode

Select this check box to display each step during processing entries in a database.

 

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

NB_LINE_UPDATED: the number of rows updated. This is an After variable and it returns an integer.

NB_LINE_INSERTED: the number of rows inserted. This is an After variable and it returns an integer.

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

This component is used as an Output component. It requires an Input component and a Row > Main link as input.

Log4j

If you are using a subscription-based version of the Studio, the activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Related scenario

For a similar scenario using MySQL database, see Tracking data changes using Slowly Changing Dimensions (type 0 through type 3).