tELTTeradataMap - 6.3

Talend Open Studio for Big Data Components Reference Guide

Talend Open Studio for Big Data
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The three ELT Teradata components are closely related, in terms of their operating conditions. These components should be used to handle Teradata DB schemas to generate Insert statements, including clauses, which are to be executed in the DB output table defined.


Helps to graphically build the SQL statement using the table provided as input.


Uses the tables provided as input, to feed the parameter in the built statement. The statement can include inner or outer joins to be implemented between tables or between one table and its aliases.

tELTTeradataMap properties

Component family


Basic settings

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.


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.


ELT Teradata Map editor

The ELT Map editor allows you to define the output schema as well as build graphically the SQL statement to be executed. The column names of schema can be different from the column names in the database.


Style link

Select the way in which links are displayed.

Auto: By default, the links between the input and output schemas and the Web service parameters are in the form of curves.

Bezier curve: Links between the schema and the Web service parameters are in the form of curve.

Line: Links between the schema and the Web service parameters are in the form of straight lines.

This option slightly optimizes performance.


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 where Properties are stored. The following fields are pre-filled in using fetched data.



Database server IP address



Name of the database


Username and Password

DB 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.

Advanced settings

Query band

Select this check box to use the Teradata Query Banding feature to add metadata to the query to be processed, such as the user running the query. This can help you, for example, identify the origin of this query.

Once selecting the check box, the Query Band parameters table is displayed, in which you need to enter the metadata information to be added. This information takes the form of key/value pairs, for example, DpID in the Key column and Finance in the Value column.

This check box actually generates the SET QUERY_BAND FOR SESSION statement with the key/value pairs declared in the Query Band parameters table. For further information about this statement, see

This check box is not available when you have selected the Using an existing connection check box. In this situation, if you need to use the Query Band feature, set it in the Advanced settings tab of the Teradata connection component to be used.


tStatCatcher Statistics

Select this check box to collect log data at the component level.

Dynamic settings

Click the [+] button to add a row in the table and fill the Code field with a context variable to choose your database connection dynamically from multiple connections planned in your Job. This feature is useful when you need to access database tables having the same data structure but in different databases, especially when you are working in an environment where you cannot change your Job settings, for example, when your Job has to be deployed and executed independent of Talend Studio.

The Dynamic settings table is available only when the Use an existing connection check box is selected in the Basic settings view. Once a dynamic parameter is defined, the Component List box in the Basic settings view becomes unusable.

For examples on using dynamic parameters, see Scenario 3: Reading data from MySQL databases through context-based dynamic connections and Scenario: Reading data from different MySQL databases using dynamically loaded connection parameters. For more information on Dynamic settings and context variables, see Talend Studio User Guide.

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.


tELTTeradataMap is used along with a tELTTeradataInput and tELTTeradataOutput. Note that the Output link to be used with these components must faithfully reflect the name of the tables.


The ELT components do not handle actual data flow but only schema information.

Connecting ELT components

The ELT components do not handle any data as such but table schema information that will be used to build the SQL query to execute. Therefore the only connection required to connect these components together is a simple link.

Note that the output name you give to the link when creating it should always be the exact name of the table to be accessed as this parameter will be used in the SQL statement generated.

For the related topic, see Talend Studio User Guide.

Mapping and joining tables

In the ELT Mapper, you can select specific columns from the input schema and include them in the output schema.

  • As you would do it in the regular Map editor, simply drag & drop the columns from the input schema towards the output table defined.

  • Use the Ctrl or Shift key for multiple selection of contiguous or non-contiguous table columns.

You can implement explicit joins to retrieve various data from different tables.

  • Select the Explicit join check box for the relevant column of the input schema and then select a type of join from the join list in the upper right corner of the input schema.

  • Possible joins include: INNER JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN, FULL OUTER JOIN and CROSS JOIN. By default, the INNER JOIN is selected.

You can also create alias tables to retrieve various data from the same table.

  • In the input area, click the [+] button in the upper left corner of the map editor to create a new alias.

  • Select the table on which the alias is based.

  • Type in a new name for the alias table, preferably not the same as the main table.

Adding where and other clauses

You can also restrict the Select statement based on a Where clause and/or other clauses such as Group By, Order By, etc. by clicking the Add filter row button at the top of the output table in the map editor.

To add a restriction based on a Where clause, click the Add filter row button and select Add a WHERE clause from the pop-up menu.

To add a restriction based on Group By, Order By etc., click the Add filter row button and select Add an other(GROUP...) clause from the pop-up menu.

Make sure that all input components are linked correctly to the ELT Map component to be able to implement all inclusions, joins and clauses.

Generating the SQL statement

The mapping of elements from the input schemas to the output schemas creates instantly the corresponding SELECT statement. The clauses are also included automatically.

Scenario: Mapping data using a subquery

This scenario describes a Job that maps the data from two input tables PreferredSubject and CourseScore to the output table TotalScoreOfPreferredSubject using a subquery.

The PreferredSubject table contains the student's preferred subject data. To reproduce this scenario, you can load the data to the table from a CSV file like the following. For how to load data to a Teradata table, see Scenario: Loading data into a Teradata database.

1;Amanda;art;Amanda prefers art.
2;Ford;science;Ford prefers science.
3;Kate;art;Kate prefers art.

The CourseScore table contains the student's subject score data. To reproduce this scenario, you can load the data to the table from a CSV file like the following. For how to load data to a Teradata table, see Scenario: Loading data into a Teradata database.

1;Amanda;science;math;85;science score
2;Amanda;science;physics;75;science score
3;Amanda;science;chemistry;80;science score
4;Amanda;art;chinese;85;art score
5;Amanda;art;history;95;art score
6;Amanda;art;geography;80;art score
7;Ford;science;math;95;science score
8;Ford;science;physics;85;science score
9;Ford;science;chemistry;80;science score
10;Ford;art;chinese;75;art score
11;Ford;art;history;80;art score
12;Ford;art;geography;85;art score
13;Kate;science;math;65;science score
14;Kate;science;physics;75;science score
15;Kate;science;chemistry;80;science score
16;Kate;art;chinese;85;art score
17;Kate;art;history;80;art score
18;Kate;art;geography;95;art score

Before the Job execution, there is no data in the output table TotalScoreOfPreferredSubject:


Dropping and renaming the components

  1. Create a new Job and add the following components by typing their names in the design workspace or dropping them from the Palette: two tELTTeradataInput components, two tELTTeradataMap components, and one tELTTeradataOutput component.

  2. Rename two tELTTeradataInput components to PreferredSubject and CourseScore respectively, two tELTTeradataMap components to ELTSubqueryMap and ELTMap respectively, and the tELTTeradataOutput component to TotalScoreOfPreferredSubject.

Configuring the input components

  1. Double-click PreferredSubject to open its Basic settings view.

  2. In the Default Table Name field, enter an input table name. In this example, it is PreferredSubject.

  3. Click the [...] button next to Edit schema to define the schema of the input table PreferredSubject in the schema editor.

    Click the [+] button to add four columns, SeqID with the DB Type set to INTEGER, StuName, Subject, and Detail with the DB Type set to VARCHAR.

    Click OK to validate these changes and close the schema editor.

  4. Connect PreferredSubject to ELTMap using the Link > PreferredSubject (Table) link.

  5. Double-click CourseScore to open its Basic settings view.