Data-Integration-Developer Talend Data Integration Certified Developer Exam Questions and Answers

To reference the value of a context variable you defined, you can use the syntax context.variable_name, where variable_name is the name of the context variable. For example, if you have a context variable named path, you can reference its value by using context.path. You do not need to specify the context name (such as test or prod) or use parentheses or brackets around the variable name. References: Talend Data Integration — Software to Connect, Access, and Transform Data | Talend,

To reference the value of a context variable you defined, you can use the syntax context.variable_name, where variable_name is the name of the context variable. For example, if you have a context variable named path, you can reference its value by using context.path. You do not need to specify the context name (such as test or prod) or use parentheses or brackets around the variable name. References: Talend Data Integration — Software to Connect, Access, and Transform Data | Talend, [Contexts - 7.3]

You need to use the following code in a tJava component to write a nb_line variable:

int nb_line = (Integer)globalMap.get(“tFileInputDelimited_1_NB_LINE”);

This code retrieves the value of the global variable tFileInputDelimited_1_NB_LINE, which stores the number of rows processed by the tFileInputDelimited component, and assigns it to an integer variable named nb_line. You can then use this variable to print or manipulate the number of rows in your Job. Note that you need to use globalMap.get, not globalMap.put, to access the value of a global variable.

To build a job to run outside Talend Studio that must run on both Linux and Windows, you need to select Build Job because jobs are runnable on all platforms. The Build Job option allows you to export your job as an executable file that can be run independently from Talend Studio on any platform that supports Java. You can access this option by right-clicking on your job in the Repository tree view and selecting Build Job. This will open a dialog box where you can configure the build settings, such as destination folder, archive name, context, etc.

You do not need to specify All for the Shell launcher option in the Build Job window, configure the job properties before building the job, or build one package for each platform. These methods are not necessary or available in Talend Studio and may cause errors or unexpected results. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Build Job - 7.3]

A row is an element that carries data between two components in a Job. A row is also called a link or a connector. A row can be of different types, such as Main, Lookup, Reject, Iterate, etc. A subjob is a group of components that are connected together and executed as a single unit. A trigger is an element that controls the execution flow of a Job or a subjob. A trigger can be of different types, such as OnSubjobOk, OnComponentOk, RunIf, etc.

To identify execution times to verify the effectiveness of your changes, you can use one of these methods:

• Reading the time stamps from the execution console in the Run view. This method allows you to see the start and end time of each subjob and component in your job, as well as the total execution time of the job. You can also see the number of rows processed by each component and the status of the job (success or failure).
• Observing the execution times that annotate the flows in the Designer. This method allows you to see the execution time of each flow (main, lookup, reject, etc.) between components in your job. You can also see the number of rows processed by each flow and the throughput (rows per second) of each flow.

You cannot use these methods to identify execution times:

• Observing the execution time in the Code view. This method does not show you the execution time of your job or its components, but only the generated code of your job in Java or Perl. The Code view is useful for debugging or customizing your code, but not for measuring performance.
• Comparing time stamps in Trace Debug mode. This method does not show you the execution time of your job or its components, but only the values of eachcolumn for each row processed by your job. The Trace Debug mode is useful for tracing data quality or transformation issues, but not for measuring performance. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Run view - 7.3], [Designer - 7.3], [Code view - 7.3], [Trace Debug mode - 7.3]

The tMap component allows you to configure multiple outputs for your data transformation and mapping. You can apply filter expressions on each output to filter out the rows that meet certain criteria. For example, if you want to send only the rows that have CA as the state value to one output, you can use CA.equals(row1.state) as the filter expression for that output. The filter expression evaluates to true or false for each row, and only the rows that evaluate to true are sent to the output. In this case, only Thomas Coolidge and Andrew Taylor have CA as their state value, so they are sent to the CA output. Similarly, only Calvin Adams has NY as his state value, so he is sent to the NY output. The Rejects output has no filter expression, so it receives all the rows from the input by default. However, since there is a conflict between the CA and NY outputs and the Rejects output, only the rows that are not sent to any other output are sent to the Rejects output. In this case, there are no such rows, so the Rejects output receives no data. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend,

The tLogCatcher component can catch exceptions from three types of components: tWarn, tDie, and Java Exception. The tWarn component is used to trigger a warning message that can be caught by the tLogCatcher component for an exhaustive log. The tDie component is used to stop the execution of a job or a subjob and return an error code that can be caught by the tLogCatcher component for an exhaustive log. The Java Exception component is used to handle any Java exception that occurs during the execution of a job or a subjob and pass it to the tLogCatcher component for an exhaustive log. The tLogCatcher component cannot catch exceptions from other types of components, such as OnSubjobError Exception or tAssertCatcher. The OnSubjobError Exception is a trigger that is activated when an error occurs in a subjob and can be used to perform some actions after the error, such as sending an email or logging a message. The tAssertCatcher component is a component that collects the assert data generated by the tAssert component and passes it on to the output defined. The tAssert component is used to verify if a condition is true or false and generate an assert data accordingly. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [tLogCatcher properties - 7.3], [tWarn properties - 7.3], [tDie properties - 7.3], [Java Exception properties - 7.3], [OnSubjobError properties - 7.3], [tAssertCatcher properties - 7.3], [tAssert properties - 7.3]

The tMap component allows you to perform data transformations and joins between multiple input sources and output targets. You can configure different types of joins between the main input and the lookup tables, such as inner join, left outer join, right outer join, etc. An inner join returns only the matching rows from both tables based on a join condition. If a row from the main input does not match any row from the lookup table, it is considered as an inner join reject. You can configure an output to collect these rejects by setting the Catch inner join reject option to true. If you do so, the data will flow only to that output and not to the main output. If you do not configure an output to collect the rejects, the data will be ignored and no error will be raised. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [tMap properties - 7.3]

To run a job that has been exported by a colleague to run outside Talend Studio, you need to extract the content of the archive and run the batch file or the shell script. The archive file contains all the files and libraries required to run the job independently from Talend Studio on any platform that supports Java. The archive file also contains two executable files: a batch file (.bat) for Windows platforms and a shell script (.sh) for Linux platforms. You need to run the appropriate file for your platform by double-clicking on it or using a command line tool. This will launch the job and display its output in a console window.

You do not need to extract the contents of the archive and run both the batch file and shell script, install the job and start the resulting service, or extract the files from the archive and run the JAR file. These methods are not correct or available in Talend Studio and may cause errors or unexpected results. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Build Job - 7.3]

To retrieve records that have a specific value based on a variable, you can use a tDBInput component with a context variable in the SQL query. A context variable is a variable that can store a value that can be changed at runtime or between different contexts. A context variable can be used in various components to parameterize their properties or expressions. A tDBInput component is used to read data from a database table by executing an SQL query. You can use a context variable in the SQL query to filter the records based on a dynamic value. For example, if you have a context variable named country that stores the value of the country you want to filter by, you can use it in the SQL query of the tDBInput component as follows:

SELECT id, address, country FROM customers WHERE country = ‘context.country’

This will retrieve only the records that have the same value as the context variable country in the country column.

You do not need to use a Run if trigger, a tMatchGroup component, or a tFilterColumns component to achieve this. A Run if trigger is used to execute a subjob conditionally based on a logical expression. A tMatchGroup component is used to group similar records based on matching rules and output them as master or duplicate records. A tFilterColumns component is used to select or remove columns from an input flow based on a list of column names. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Contexts - 7.3], [tDBInput properties - 7.3], [Run if properties - 7.3], [tMatchGroup properties - 7.3], [tFilterColumns properties - 7.3]

The design workspace in Talend Studio allows the user to graphically connect components in a Job to run a dataflow process. The design workspace is the main area where the user can design the data integration logic by dragging and dropping components from the palette and linking them with connectors. The design workspace also shows the schema of each component, which defines the structure and type of the data.

 The tDBInput component allows you to configure the connection properties either by using a built-in mode or by using a repository mode. The built-in mode lets you set all the relevant properties manually, such as host, port, database, username, password, etc. The repository mode lets you reuse an existing connection metadata that is stored in the repository. If you have multiple jobs that use different credentials to connect to a common database server, you should use the built-in mode and set the properties for each job individually. This way, you can avoid creating multiple connection metadata in the repository and maintain them separately. References: Talend Data Integration — Software to Connect, Access, and Transform Data | Talend, [tDBInput properties - 7.3]