tCassandraRow properties - 6.1

Talend Components Reference Guide

EnrichVersion
6.1
EnrichProdName
Talend Big Data
Talend Big Data Platform
Talend Data Fabric
Talend Data Integration
Talend Data Management Platform
Talend Data Services Platform
Talend ESB
Talend MDM Platform
Talend Open Studio for Big Data
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Talend Open Studio for Data Quality
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Talend Real-Time Big Data Platform
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Component Family

Big Data / Cassandra

 

Function

tCassandraRow is the specific component for this database query. It executes the Cassandra Query Language (CQL) query stated in the specified database. The row suffix means the component implements a flow in the Job design although it does not provide output.

Purpose

Depending on the nature of the query and the database, tCassandraRow acts on the actual DB structure or on the data (although without handling data).

Basic settings

Property type

Either Built-In or Repository.

Built-In: No property data stored centrally.

Repository: Select the repository file where the properties are stored.

 

Use existing connection

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

  DB Version Select the Cassandra version you are using.
 

API type

This drop-down list is displayed only when you have selected the 2.0 version of Cassandra from the DB version list. From this API type list, you can either select Datastax to use CQL 3 (Cassandra Query Language) with Cassandra, or select Hector to use CQL 2.

Note that the Hector API is deprecated for the 2.0 or later version of Cassandra, but it is still available for use in the Studio so that you can be flexible about the version of the query language to be used with Cassandra 2.0.0.

 

Host

Type in the IP address or hostname of the Cassandra server.

 

Port

Type in the listening port number of the Cassandra server.

 

Required Authentication

Select this check box to provide credentials for the Cassandra authentication.

This check box appears only if you do not select the Use existing connection check box.

 

Username

Fill in this field with the username for the Cassandra authentication.

 

Password

Fill in this field with the password for the Cassandra authentication.

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.

Keyspace configuration

Keyspace

Type in the name of the keyspace on which you want to execute the CQL commands.

Column family configuration

Column family

Name of the column family.

 

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.

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.

 

Query

Type in the CQL command to be executed.

By default, the query is not case-sensitive. This means that at runtime, the column names you put in the query are always taken in lower case. If you need to make the query case-sensitive, put the column names in double quotation marks.

 

Die on error

This check box is cleared by default, meaning to skip the row on error and to complete the process for error-free rows.

Advanced settings

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.

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.

Limitation

Currently, the select commands are not supported.