DATA-INTEGRATION-DEVELOPER Practice Questions

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 the same 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. Reference: Talend

Open Studio: Open-source ETL and Free Data Integration | Talend, [Joblets - 7.3], [tRunJob properties

- 7.3], [Contexts - 7.3]

To add a Joblet to your Talend Job, you can use one of these options: Type the Joblet name on the Studio canvas, then select it from the Palette drop-down menu. This will create a Joblet container on your canvas that contains all the components and links of your Joblet. Drag the Joblet from Repository tree view to designer canvas. This will also create a Joblet container on your canvas that contains all components and links of your Joblet. Drag Joblet from Palette to design workspace. This will open a dialog box where you can select an existing Joblet from Repository or create a new one. You cannot use a tRunJob component and select Joblet from drop-down menu, nor right-click Joblet from Palette and select Add option. These methods are not available in Talend Studio and may cause errors or unexpected results. Reference: Talend Open Studio: Open-source ETL and Free Data Integration | Talend, [Joblets - 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. Reference: Talend Open Studio: Open-source ETL and Free Data Integration | Talend

A middleware application is a software that acts as a mediator between different data sources and

data consumers. It can normalize data and bring it into a master data pool, which is a centralized

repository of consistent and quality data. This can help a data professional to combine multiple data

sources into a relational database to improve their business efficiency. A middleware application can

also provide data integration services such as data transformation, validation, cleansing, and

enrichment. Reference: What is Data Integration?, What is Middleware?

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. Reference: 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]

To specify the remote JobServer to execute a job, you need to use the Target Exec tab in the Run view

of Talend Studio. The Run view allows you to configure and execute your job from Talend Studio. The

Target Exec tab allows you to select whether you want to run your job locally or remotely on a

JobServer. A JobServer is a server application that allows you to execute jobs remotely from Talend

Studio or Talend Administration Center. To run your job on a remote JobServer, you need to select

Remote Jobserver option from the drop-down menu and select or add a JobServer connection from

the list.

You do not need to use Job settings section of Project Settings window, Extra tab in Job view, or

Run/Debug section in P

window. These windows are not used to specify remote JobServer

execution. The Job settings section of Project Settings window is used to configure general settings

for your jobs, such as versioning, statistics, logs, etc. The Extra tab in Job view is used to configure

extra features for your job, such as implicit context load, tStatCatcher, tLogCatcher, etc. The

Run/Debug section in Preferences window is used to configure run/debug settings for your Talend

Studio, such as JVM arguments, execution mode, etc. Reference: Talend Open Studio: Open-source

ETL and Free Data Integration | Talend, [Run view - 7.3], [Project Settings - 7.3], [Job view - 7.3],

[Preferences - 7.3]

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 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 each column 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. Reference: 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]

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. Reference: Talend Data Integration — Software to Connect, Access, and Transform

Data | Talend,

To design a job that can run in two contexts, Test and Production, and run it as a standalone job

outside Talend Studio, you need to do the following steps:

Define the context variables and values for each context in the Contexts tab of your job. A context

variable is a variable that can store a value that can be changed at runtime or between different

contexts. You can use context variables to parameterize the properties or expressions of your job

components.

Build the job with the desired context selected in the Build Job window. 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 need to select the context that you want to use for your job execution from the drop-down

menu.

Extract the content of the archive file that contains your job executable files and libraries. 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.

If you need to run the job in a different context, you need to build a separate copy of the job with the

other context selected in the Build Job window. You cannot change the context of an already built job

without rebuilding it.

You do not need to build the job with the Context scripts option selected in the Build Job window,

edit the script according to the context in which you want to run the job, set the desired context as

the default, rebuild the job if you need to run it in a different context, or be prompted for the

context. These methods are not correct or available in Talend Studio and may cause errors or

unexpected results. Reference: Talend Open Studio: Open-source ETL and Free Data Integration |

Talend, [Build Job - 7.3], [Contexts - 7.3]