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

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 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

Trace Debug mode is a feature that allows you to trace each row processed by your job components and see the values of each column in each row. You can access this mode by opening the Debug Run tab of the Run view and clicking on Trace Debug button.

The capabilities that Trace Debug mode provides are:

• Breaking when an input column fulfills a condition. 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. To set a breakpoint based on a condition, you need to right-click on a trace on your jobdesign workspace and select Show Breakpoint Setup option. This will open a dialog box where you can enter a condition or an expression for your breakpoint.
• Advancing one row at a time. You can advance the execution of your job one row at a time by using the Step Over button in the toolbar of the Run view. This will allow you to see how each row is processed by your job components and how it affects the output data.

The capabilities that Trace Debug mode does not provide are:

• Filtering which data is propagated by a flow. You cannot filter which data is propagated by a flow in Trace Debug mode. A flow is a link that shows 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. However, you cannot change which rows are propagated by a flow based on a condition or an expression.
• Advancing one column at a time. You cannot advance the execution of your job one column at a time in Trace Debug mode. You can only advance the execution of your job one row at a time by using the Step Over button in the toolbar of the Run view. This will allow you to see how each row is processed by your job components and how it affects the output data. However, you cannot see how each column is processed by your job components and how it affects the output data.
• Breaking on a selected line of code. You cannot break on a selected line of code in Trace Debug mode. You can only break on a trace based on a condition or an expression that involves input data columns. To break on a selected line of code, you need to use Java Debug mode. 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. You can access this mode by switching to the Java perspective and clicking on the Debug button in the toolbar of the Code view. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Trace Debug mode - 7.3], [Java Debug mode - 7.3]

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]

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 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.

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.

The Start component in a subjob triggers the execution of the next subjob in a sequential order. The Start component is used to define where a subjob begins and to link it with other subjobs within a job. The Start component has only one output link that can be connected to any other component in the same subjob or to another Start component in another subjob. When a subjob completes successfully, it sends an OnSubjobOk trigger to its Start component, which then activates the next subjob linked to it. The Final component, on the other hand, is used to define where a subjob ends and to perform some actions after its completion, such as sending anemail or logging a message. The Final component has no output link and does not trigger any other subjob. The Input component and any other component in a subjob do not trigger any other subjob by themselves, unless they are connected to a Start component through an output link or an OnComponentOk trigger. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Start properties - 7.3], [Final properties - 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]

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.

You do not need to use a file, command line options, or Java function parameters to pass parameters to a different job. These methods are not supported by Talend Studio and may cause errors or unexpected results. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [tRunJob properties - 7.3], [Contexts - 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]

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

In some instances, after applying changes to a component schema, you are asked if you would like to propagate the changes. This prompt is significant because it allows you to confirm that you want to apply the schema changes to the next component in the Job. This can save you time and effort by automatically updating the schema of the downstream component, instead of manually editing it. However, you should be careful when propagating changes, as it may overwrite existing schemas or cause errors in the Job logic. You can also choose to cancel the propagation and edit the schema manually.

To execute the compiled job outside Talend Studio, you need to right-click on the job in the Repository tree view and select Build Job option. This 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 click the Export button in the Edit Properties window, right-click on the job in the Repository and select Export items, or select Save As on the main File menu. These options are not used to execute the compiled job outside Talend Studio. The Export button in the Edit Properties window is used to export your job properties as an XML file. The Export items option is used to export your items (such as jobs, metadata, routines, etc.) as an archive file that can be imported into another project or workspace. The Save As option is used to save a copy of your job with a different name or location. References: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Build Job - 7.3]

 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]

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]