INFORMATICA INTERVIEW QUESTIONS AND ANSWERS
Globalization gives birth to growing economies, consequently bringing many large conglomerates into existence worldwide. Data warehousing is one of the cornerstones of conglomerate industries. Informatica is an effective tool in the field of data warehousing. Informatica PowerCenter is a type of tool that extracts, transforms, and loads (ETL) data from different sources for industries. Powercenter shapes and stores the data based on the requirements of the industry that is using the tool. By perusing our Informatica course syllabus, you can learn more about what our institute has to offer.
Having a foundational knowledge of the frequently asked interview questions about Informatica PowerCenter will help job seekers effortlessly secure a job in the field of ETL data processing.
Informatica interview questions
What is the difference between ETL and ELT?
ETL stands for extracting, transforming, and loading. Here the data is transformed, and then the loading is done as part of the final process.
ELT is the process where the data is loaded, and then the transformation is performed as the final part of the process.
Briefly explain the process of ETL. (Informatica interview question and answer).
Extracting is the process of deriving data from different sources. The types of derived data are usually databases, XML, APIs, IMS, JSON, etc.
Transforming is the process of shaping the data into a usable form. Usually, in the transformation part of the process, things like correcting errors, removing duplicates, establishing a hierarchy in data, and making adjustments are done to meet the standards of the business.
Loading is the process where the transformed data is loaded into a data warehouse per requirement. This is the final part of the process.
Learn more about our ETL testing course syllabus here.
What is Informatica PowerCenter?
Informatica PowerCenter is an ETL tool capable of extracting, transforming, and loading data into the required database warehouse as per the requirements of the industry.
Explain the main features of Informatica PowerCenter.
- ETL-Informatica PowerCenter is used to extract, transform, and load data from various sources into the required database warehouse for conglomerate industries.
- Metadata: Metadata is the related information about a particular piece of data that accompanies the data itself. Informatica has a separate application called Metadata Manager, which is used to analyze and manage metadata from its respective repositories.
- Influence on Workflow: Informatica has specially designated tools like the Workflow Designer, which is used to connect various tasks in the workflow with links, thereby making the tasks efficient in the interface.
- Support for various data sources: Informatica PowerCenter supports various data sources in its functionality, such as Oracle, Teradata, SQL, XML, etc.
What are the various services that Informatica PowerCenter has to offer?
The following are the services that Informatica PowerCenter has to offer:
- MetaData management
- Cloud Interconnection
- Warehousing of Data
- ETL (extracting, transforming, and loading)
- B2B integration
- Data syncing
- Data replication, etc.
For more information on data warehousing, check out our Data Warehousing Course Syllabus.
What are the major applications of Informatica PowerCenter?
Informatica PowerCenter has three major applications, which are listed below:
- PowerCenter client
- PowerCenter repository
- PowerCenter server
Briefly explain the major applications in Informatica PowerCenter. (Informatica developer interview question)
- PowerCenter client: This application has the tools that are used for mapping data, managing metadata repositories, and creating sessions to load the data. The PowerCenter Client has the following tools:
- Designer: Used to create a mapping for data
- Mapping Architect for Visio: This is used for creating mapping templates that subsequently create more than one mapping.
- Repository Manager: Used to assign permissions to individuals and groups and manage folders relating to metadata. It is located in the HubConsole.
- Workflow Monitor: It receives information from repositories and integration services and displays workflows that run at least once.
- Workflow Manager: Used to create schedules and run workflows and tasks (tasks like session tasks and command tasks) for respective integrated services.
- PowerCenter Repository: This stores the information required to do the ETL process. It functions within the relational database section. There are two types of repositories: global and local repositories. Enroll in our Informatica training program to become an expert in PowerCenter and repositories. Click here to learn more about Informatica training in Chennai.
- PowerCenter Server: This is the server where major functions such as the ETL are performed. One of the most vital components in Informatica’s landscape
What is the PowerCenter Integration Service?
The functions of the PowerCenter Repository have some relationship with metadata. The PowerCenter Repository Service fetches metadata by connecting to the repositories. The Power Center Integration Service can load and combine data from different source types and platforms.
What is a workflow in Informatica PowerCenter?
To perform the extracting, transforming, and loading (ETL) process, a certain set of instructions is required to specify when and how to run tasks relating to ETL, and Workflow is the set of instructions that does that.
What is a session in the PowerCenter Integration Service?
Sessions are the required instructions that inform the PowerCenter Integration Service on how to move data from its source to targets.
What is mapping? (Informatica interview questions for experienced candidates)
Mapping is the set of collections of source and target objects that are interconnected by transformations, where the transformation defines the data flow.
What is the difference between a session and a workflow?
A session derives data from mapping sources and applies the transformation rules that customize the mapping process. The main difference is that a session is a type of workflow, but a workflow cannot be considered a session.
What is SOAP in Informatica PowerCenter? (Informatica PowerCenter interview question)
SOAP stands for Simple Object Access Protocol. It is an internet protocol format for messaging and communication in web services.
What are the components of SOAP?
The following are the components of SOAP:
- SOAP Envelope: This defines the skeleton of the message, e.g., content, who it is meant to reach, and whether it is necessary or not.
- SOAP Header: Features can be added to SOAP messages in a scattering manner using SOAP Header.
- SOAP Body: This part contains the important and necessary information about the message.
Learn more about SOAP and Web Services through our web service courses at Softlogic Systems.
What is a Web Services Hub?
WebServices Hub is the application that connects PowerCenter web services to external clients. SOAP requests from clients are processed through web services using the web service hub.
Elaborate on the types of web service hubs.
There are two types of web service hubs:
- Batch Web Services: It monitors sessions and workflow in the center using operations that are included in batch web services.
- Real-Time Web Services: These are workflows enabled as web services that are capable of receiving requests and generating replies in SOAP format.
What are Mapplets in Informatica?
Mapplets are objects that have transformations that are potentially used in multiple mappings but are reusable. Mapplets can contain other Mapplets too.
What is dynamic mapping?
Dynamic mapping can include changes in source and target at runtime. Dynamic mapping is mostly used to manage metadata changes when reusing the logic of mapping. To create a dynamic mapping, one needs to alter rules, parameters, and transformation properties.
What is source-qualifier transformation, and for what tasks is it used?
Source Qualifier Transformation changes source data types to their indigenous power center data types. It is compulsory for flat files.
Source Qualifier Transformation can be used to accomplish the following task:
- To create a custom query to do a sum of calculations,.
- The ORDER BY clause is added to the default SQL Query by integrated service when the number of sorted ports is defined.
- It’s possible to join two or more tables with primary key-foreign key relationships by linking the sources to one Source Qualifier transformation.
- The Select Distinct clause can make the Integrated Service add the Select Distinct statement to the primary SQL query.
- If the filter condition is included, then the integration service adds the WHERE clause to the default query.
What is the difference between a source qualifier and a filter transformation in Informatica?
Source qualifier changes filter rows from only relational sources.
Whereas, the filter transformation converts filter rows from any type of source.
What are the rules when overriding a lookup query? (Informatica interview question for 10 years experience)
- Lookup queries can be overridden for relational lookups.
- The entire SELECT statement that is required by the database should be entered.
- All database words should be in quotes.
- All lookup and return fields should be included in the SELECT statement.
- The alias should be used for each column in a query.
- If column aliases are not used, then the mapping task fails with the following error:
Failed to initialize transformation [<Lookup Transformation Name]
- To override the ORDER BY clause, append “-” at the end of the query.
An ORDER BY clause is generated by the mapping task, even when someone enters one in the override. Therefore, he or she must enter two dashes (-) at the end of the query to suppress the generated ORDER BY clause.
- If the ORDER BY clause contains multiple columns, the columns should be entered in the same order as the fields in the lookup condition.
- If the mapping task uses SQL ELT optimization or is based on a mapping in SQL ELT mode, the ORDER BY clause cannot be overridden, or the generated ORDER BY clause with comment notation cannot be suppressed.
- If a lookup cache shares multiple lookup transformations, using the same lookup SQL override for each lookup transformation is recommended.
- When a lookup transformation that returns all rows is configured, the mapping task builds the lookup cache with sorted keys. When the transformation retrieves all rows in a lookup, the mapping task builds the data cache with the keys in sorted order. The mapping task cannot retrieve all the rows from the cache if the rows are not sorted. The person might get an unexpected result if the data needs to be sorted on the keys. Parameters cannot be included in the lookup SQL override.
- If a lookup SQL override is configured along with a lookup source filter in the same transformation, the mapping task ignores the filter.
Explain partitioning and parallel processing in Informatica PowerCenter. (Informatica interview question for 4 years experience)
Partition is the subset of data that is released in a single thread; this saves time during the data flow. Session partitioning is the process of splitting large data sets into smaller subsets that can be transmitted in a parallel thread. The more partitioning, the more threads, which will eventually increase session performance.
Components of partitioning
Stage: It is the pipeline for dataflow, but as partitioning happens, it is termed threads.
Partition type: It is the algorithm that distributes data among the partitions. This influences the Integration Service on how to distribute the data into the partition thread.
Partition point: This is the division that creates two or more partition threads.
The following are the types of session partitions:
- Database Partitioning: The database system is queried for table partition information by the integration service.
- Round Robin Partitioning: This type is used to distribute partitions equally among all partition threads.
- Hash Auto-Keys Partitioning: This type of partition groups rows of data using a hash function. The Integration Service uses all grouped or sorted ports as a compound partition key when using Hash Auto-Key.
- Hash User-Keys Partition: Here, the Integrated Service uses a hash key to group rows of data based on the user-defined partition key.
- Key Range Partitioning: This type of partitioning uses one or more ports to form a compound partition key for a source or target. Eventually, the integration service will transmit data to each partition port, depending on the specified range of the port.
- Pass-Through Partitioning: This is a straightforward partition process where the integration services pass all data rows through a single partition point and so on without redistributing or scattering them.
Informatica helps in the distribution and management of large amounts of data for industries to manage and analyze. Informatica’s ETL-based processing network makes the management and processing of data more efficient, which makes the whole tool an efficient endeavor. Learning Informatica is very resourceful in this day and age, and we think that these interview questions and answers will help job seekers land the job with ease. Check out our training program to enroll in our institute.