Talend Data-Integration-Developer Talend Data Integration Certified Developer Exam Exam Practice Test

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.

The context in which a job is run can be affected by different factors, such as the context chosen by the developer when running the job, or the tRunJob component that can influence the context in which the child job runs. The context chosen by the developer when running the job can be selected from the Basic Run tab of Run Job section in Talend Studio. This allows the developer to test the job with different sets of context variables without modifying the job design. The tRunJob component can be used to call another job as a subjob within a parent job. The tRunJob component can pass the context parameters from the parent job to the child job, or use a specific context for the child job. This allows the developer to reuse existing jobs and control their execution contexts. The tContextLoad component and the tContextDump component do not affect the context name in which a job is run, but they can affect the context values. The tContextLoad component can load context parameters from a file or a database table at runtime and overwrite the existing values. The tContextDump component can display or save the current context parameters and their values for debugging purposes. References: Talend Data Integration — Software to Connect, Access, and Transform Data | Talend, [tRunJob properties - 7.3], [tContextLoad properties - 7.3], [tContextDump properties - 7.3]

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 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]

To create a Joblet from an existing Job, you can follow these steps:

• Open the Job that you want to create a Joblet from.
• Select the components that you want to include in the Joblet.
• Right-click on the selected components and select Create Joblet from the context menu.
• In the Create Joblet dialog box, enter a name and description for the Joblet.
• Click Finish to create the Joblet.

References:

• Talend Open Studio User Guide: Creating a Joblet from a Job: https://help.talend.com/r/en-US/8.0/studio-user-guide/creating-joblet-from-job

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]

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 create a centralized metadata connection to a database server for an application, you need to take the following steps before building a job that reads from that database:

• Create DB Connections metadata to describe the database connection. You can do this by right-clicking on the DB Connections node in the Repository and selecting Create Connection. You can then enter the connection details, such as host, port, database, username, password, etc., and test the connection.
• Retrieve schemas from the database connection. You can do this by expanding the DB Connections node in the Repository and right-clicking on the connection you created. You can then select Retrieve Schema and choose the tables or views you want to import as metadata schemas. You can also edit or customize the schemas as needed.
• Drag the DB Connection metadata into the Designer to read from the database component. You can do this by dragging the connection or a specific schema from the Repository to the Designer workspace. This will automatically create a database input component (such as tMysqlInput) that is configured with the connection and schema properties. You can then use this component to read data from the database in your job.

You do not need to add a tMap component to handle and convert DB Types, nor a tCreateTable component to create a table in the database. These components are not required for reading data from an existing database, but they can be used for other purposes, such as transforming or writing data. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [DB Connections - 7.3], [tMap properties - 7.3], [tCreateTable properties - 7.3]

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,

The tMysqlOutput component is used to write data into a MySQL database table. The Action on table parameter of this component allows you to specify what operation to perform on the table before loading data into it. The Action on table parameter supports the following operations:

• Drop table if exists and create: This operation drops the table if it already exists in the database and creates a new one with the same name and structure as defined in the schema.
• Create table: This operation creates a new table in the database with the name and structure as defined in the schema. If a table with the same name already exists, an error will be raised.
• Create table if does not exist: This operation creates a new table in the database with the name and structure as defined in the schema only if there is no table with the same name already existing in the database. If a table with the same name already exists, no action will be taken.

The Action on table parameter does not support the following operations:

• Replace: This is not an operation on the table, but on the data. The Replace parameter of the tMysqlOutput component allows you to specify whether to replace existing rows in the table with new rows based on a key attribute or to insert new rows only.
• Drop table: This is not an operation on the table, but on the database. The Drop table parameter of the tMysqlConnection component allows you to specify whether to drop the table after closing the connection or not. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [tMysqlOutput properties - 7.3], [tMysqlConnection properties - 7.3]

To create a job consisting of two subjobs, A and B, and add a Joblet C with the intention of running it between A and B, you need to do the following steps:

• Design subjob A by adding components and links to it in the Designer workspace.
• Add a Start component to mark the beginning of subjob B and link it to subjob A using an OnSubjobOk trigger.
• Design subjob B by adding components and links to it after the Start component in the Designer workspace.
• Add a tJobletTriggerInput component to your Joblet C design and link it to other components in your Joblet using data flows or triggers.
• Add a tJobletTriggerOutput component to your Joblet C design and link it to other components in your Joblet using data flows or triggers.
• Drag your Joblet C from the Repository tree view to the Designer workspace between subjob A and subjob B.
• Link your Joblet C to subjob A using an OnComponentOk trigger from the last component of subjob A to the tJobletTriggerInput component of your Joblet C.
• Link your Joblet C to subjob B using an OnComponentOk trigger from the tJobletTriggerOutput component of your Joblet C to the Start component of subjob B.

The minimum requirements to orchestrate this are adding TRIGGER_INPUT and TRIGGER_OUTPUT components into C and linking A, B, and C using OnSubjobOk triggers. These are generic components that allow you to define triggers for your Joblet without depending on specific components. You do not need to add TRIGGER_INPUT and TRIGGER_OUTPUT components into A or B, as these are regular subjobs that can use any type of components or triggers. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [tJobletTriggerInput properties - 7.3], [tJobletTriggerOutput properties - 7.3], [Joblets - 7.3], [Triggers - 7.3]

The methods that you can use to specify the schema in a tFileInputDelimited component are:

• Add the component then drag and drop a generic schema metadata item onto the component. This method allows you to reuse an existing schema that is stored in the Metadata section of the Repository. A generic schema is a schema that is not associated with any specific file format or connection type. You can create a generic schema by right-clicking on Generic Schema in the Repository and selecting Create Generic Schema.
• Drag a File delimited metadata item from the Repository onto the design workspace. This method allows you to create a new tFileInputDelimited component with a predefined schema that is based on a specific delimited file. A File delimited metadata item is a metadata item that contains information about a delimited file, such as its path, format, encoding, field separator, etc. You can create a File delimited metadata item by right-clicking on File delimited in the Repository and selecting Create File delimited.
• Add the component, open the Component view, select the Built-in schema type, then click the Edit schema button. This method allows you to create a custom schema for the tFileInputDelimited component within the Component view. A built-in schema is a schema that is defined locally for a specific component and cannot be reused by other components. You can edit a built-in schema by clicking on the Edit schema button in the Basic settings tab of the Component view.

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

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 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.

Trace Debug and Java Debug are two modes that allow you to debug your jobs in Talend Studio. Trace Debug mode allows you to trace each row processed by your job components and see the values of each column in each row. Java Debug mode allows you to debug your job code in Java or Perl and see the values of each variable or expression in your code.

The characteristics that distinguish Trace Debug from Java Debug are:

• Trace Debug mode allows row-by-row inspection of data flows, while Java Debug mode does not. Data flows are the links that show the data transfer between components in your job design workspace. In Trace Debug mode, you can see the data flow on each trace and inspect the values of each column for each row processed by your job. You can also use filters to display only the rows that match a condition or an expression. In Java Debug mode, you cannot see the data flow on each trace or inspect the values of each column for each row.
• Trace Debug mode supports breakpoints based on input data condition, while Java Debug mode does not. Breakpoints are points where the execution of your job pauses and waits for your action. You can use breakpoints to inspect your data or debug your logic at specific points of your job execution. In Trace Debug mode, you can set breakpoints on traces based on a condition or an expression that involves input data columns. For example, you can set a breakpoint to pause your job when a customer name contains a certain string or when a product price exceeds a certain value. In Java Debug mode, you can only set breakpoints on lines of code based on a condition or an expression that involves variables or expressions.

The characteristics that do not distinguish Trace Debug from Java Debug are:

• Both modes require a separate perspective. A perspective is a set of views and editors that are arranged in a specific way to support a specific task. In Talend Studio, you can switch between different perspectives, such as Integration, Debug, Profiling, etc. To use Trace Debug mode, you need to switch to the Debug perspective by clicking on the Open Perspective button and selecting Debug. To use Java Debug mode, you need to switch to the Java perspective by clicking on the Open Perspective button and selecting Java.
• Neither mode requires Java development experience. Although Java Debug mode allows you to debug your job code in Java or Perl, you do not need to have Java development experience to use it. You can use the graphical interface of Talend Studio to design your job components and properties without writing any code. You can also use the Code view to see the generated code of your job in Java or Perl and modify it if needed. However, you do not need to write any code from scratch or understand all the details of the code to use Java Debug mode. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Trace Debug mode - 7.3], [Java Debug mode - 7.3]