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

A Joblet is a reusable piece of a job that can be used in multiple jobs as a single component. A tRunJob component is a component that allows you to call another job as a subjob within a parent job. When comparing a Joblet to a tRunJob component, these statements are true:

• A Joblet uses the same context variables of the job in which it is used, unlike a tRunJob component. A context variable is a variable that can store a value that can be changed at runtime or between different contexts. A Joblet inherits the context variables from the job that contains it and does not have its own context variables. A tRunJob component can pass context variables from the parent job to the child job, or use a specific context for the child job.
• Building a Joblet typically requires the use of generic input and trigger components. A Joblet can have one or more input and output flows that connect it with other components in a job. To create these flows, you need to use generic input and trigger components, such as tJobletInput, tJobletOutput, tJobletTriggerInput, and tJobletTriggerOutput. These components allow you to define schemas and triggers for your Joblet without depending on specific components.
• The nested job called by a tRunJob component cannot use the same context variables of the job in which it is used. A nested job is a job that is called by another job using a tRunJob component. A nested job can have its own context variables or receive context variables from its parent job, but it cannot use thesame context variables as its parent job. This means that if you have two context variables with the same name in both jobs, they will be treated as separate variables and will not share values.

These statements are false when comparing a Joblet to a tRunJob component:

• The performance of tRunJob component is better than running an equivalent job using a Joblet. The performance of a Joblet is better than running an equivalent job using a tRunJob component. This is because a Joblet is integrated into the main code of the job and does not require launching another JVM process or loading another metadata object like a tRunJob component does. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Joblets - 7.3], [tRunJob properties - 7.3], [Contexts - 7.3]

Tags are used to mark specific points in the development lifecycle of a project. This can be done for a variety of reasons, such as:

• To mark the completion of a major feature or release
• To mark the start of a new development phase (e.g., QA, production)
• To mark a known good state of the codebase (e.g., before a risky change)

Tags can be used to create branches, which can then be used to develop and test new features or bug fixes. They can also be used to deploy the codebase to different environments (e.g., development, staging, production).

Examples of when to use a tag:

• When you are ready to release a new version of your application to production.
• When you have completed a major feature or milestone in the development of your application.
• Before making a risky change to your codebase, such as a database migration or refactoring.
• When you need to deploy your application to a different environment, such as staging or production.

Benefits of using tags:

• Tags can help you to keep track of the different versions of your codebase.
• Tags can help you to roll back to a previous version of your codebase if necessary.
• Tags can help you to deploy your codebase to different environments.
• Tags can help you to collaborate with other developers more effectively.

References:

• Talend Best Practices Guide: https://help.talend.com/r/en-US/8.0/software-dev-lifecycle-best-practices-guide/branching-merging-and-tagging
• Git documentation on tags: https://git-scm.com/docs/git-tag

The Sync columns button on the Basic settings tab of the Component view retrieves the schema from the input component connected in the Job and synchronizes it with the current component’s schema. This button is available for most of the components that have an input and an output schema, such as tJavaRow, tMap, tFileOutputDelimited, etc. However, this button does not retrieve and synchronize the output file schema with the input file schema for tFileOutputDelimited, as this component only has one output schema.

 To copy Job1 from Branch1 to Branch2 and preserve the change history when connecting Studio to Talend Administration Center, you need to use the Copy to branchoption. This option allows you to copy a job or a folder from one branch to another branch in the same project without losing the version history. You can access this option by switching to Branch1, right-clicking on Job1 in the Repository tree view, and selecting Copy to branch. This will open a dialog box where you can select Branch2 as the target branch and confirm the copy operation.

You do not need to use the import items, create standard job, or paste over options. These options are not used to copy jobs between branches and preserve the change history. The import items option is used to import items (such as jobs, metadata, routines, etc.) from an archive file that can be exported from another project or workspace. The create standard job option is used to create a new job with a name and a description. The paste over option is used to overwrite an existing job with another job that has been copied or cut from the same or another project. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Copy to branch - 7.3]

To call a different job within a job you are developing, you can use the tRunJob component. This component allows you to execute another job as a subjob within a parent job. To pass the parameters to the job you want to call, you can use the context parameters. Context parameters are variables that can store values that can be changed at runtime or between different contexts. You can define context parameters in the Contexts tab of your job and assign them values for each context. You can also pass context parameters from the parent job to the child job by using the Context Param tab of the tRunJob component. This way, you can parameterize the properties or expressions of the child job with the values from the parent job.

To transfer processed data stored in the tBufferOutput buffer memory back to the parent job, you need to select the Propagate the child result to output schema option in the Advanced settings of the tRunJob component. This option allows you to retrieve the data from the tBufferOutput component of the child job and send it to an output row of the parent job. The tBufferOutput component is used to store data in memory without writing it to disk or database. You can use this component to optimize the performance and memory usage of your job.

You do not need to select the Transmit whole context option in either Basic or Advanced settings of the tRunJob component. This option allows you to pass all the context parameters from the parent job to the child job without specifying them individually. This option does not affect the data transfer from the tBufferOutput component. You also do not need to select the Propagate the child result to output schema option in Basic settings of the tRunJob component, as this option is only available in Advanced settings. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [tRunJob properties - 7.3], [tBufferOutput properties - 7.3], [Contexts - 7.3]

The tables on the left side of the Map Editor window represent the schemas of the input rows. The schemas define the structure and type of the data that is coming from the input components connected to the tMap component. You can drag and drop columns from the input tables to the output tables on the right side of the Map Editor window to create mappings and transformations.

Using the following input file format as an example:

Name, Phone Abraham Smith, 510-555-5555 … Steven Doe, 613-555-5555

The tFileInputDelimited component parameters that you should configure to parse the input file correctly are Schema, Field separator, and Header. The Schema parameter defines the structure and type of the data in the input file. You can use a built-in schema or a repository schema to specify the columns and their properties. The Field separator parameter defines the character that separates each field in a row of data. In this case, it is a comma (,). The Header parameter defines the number of rows to be skipped at the beginning of the file. In this case, it is 1, as the first row contains the column names.

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 tMysqlOutput component is used to write data into a MySQL database table. The Update and Delete operations are used to modify or remove existing rows in the table based on a primary key. To define the primary key for these operations, you need to use the Use field options check box in the Advanced settings view of the component. This will enable you to specify which columns are used as keys for each operation. You can also define other options for each column, such as nullable, length, precision, etc. The Use field options check box is not available in the Basic settings view of the component. The Additional columns options check box and the Use hint options check box are used for other purposes, such as adding extra columns or hints to the SQL query, and they do not affect the primary key definition. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [tMysqlOutput properties - 7.3]

Contexts are a way of defining different sets of values for variables that are used in a job. For example, you can define a context for testing and another context for production, with different values for the database connection parameters, file paths, etc. You can then switch between the contexts easily without modifying the job design. Contexts are not automatically defined by the types of components used in the job, nor by Talend Studio. You must define the contexts yourself in the Contexts tab of your job. You can also create context groups in the Repository and reuse them in multiple jobs. References: Talend Data Integration — Software to Connect, Access, and Transform Data | Talend,

To trigger auto-completion in Talend Studio, you can use the keystrokes Ctrl + Space. This will display a list of possible suggestions based on what you have typed so far. For example, if you type context. and press Ctrl + Space, you will see a list of all the context variables you have defined. You can then select the one you want from the list or continue typing to narrow down the choices. Auto-completion can help you avoid typing errors and save time when configuring components or writing expressions. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend

To set up a server in your Talend environment that enables several members of your team to collaborate on a project, you need to enable two applications before working on a remote project: Git or SVN server instance and Talend Administration Center instance. These applications are used to manage version control and collaboration for your project.

Git or SVN server instance is a server application that allows you to store and track changes of your project files using a version control system. Git and SVN are two popular version control systems that are supported by Talend Studio. You need to have a Git or SVN server instance running and accessible by your team members before working on a remote project. You also need to have a Git or SVN client installed on each development workstation to connect to the server and perform version control operations.

Talend Administration Center is a web-based application that allows you to manage users, projects, tasks, execution servers, and licenses for your Talend environment. You need to have a Talend Administration Center instance running and accessible by your team members before working on a remote project. You also need to configure the team members and project settings in Talend Administration Center to grant access and permissions for your project. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Version control - 7.3], [Talend Administration Center - 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]