Informatica is a critical tool for data warehousing since it enables the management of huge quantities of data and makes reporting of data analysis easy. According to the study, Informatica now has a share of the market of approximately 29.4 percent, indicating that there is plenty of room for growth in the future. And if you’re interested in developing a profession in the same area, this is the ideal choice for you. All you need to do is prepare well for the career interview in order to ace it and get Informatica employment in reputable companies. As a result, we’ve included sample Informatica important scenario-based interview questions and answers below to assist applicants in reviewing them and bracing themselves for success during their job interview.
Prior to scenario-based interview questions; there are some important questions that provide you the ability to think out of the box when scenario-based queries are asked.
Informatica Scenario Based Interview Questions and answers
Question 1). How can you tell the difference between a filter transformation and a source qualifier?
|Source Qualifier Transformation
|1. It performs row-level filtering while receiving data from a source.
|1. It performs row-level filtering inside mapped data.
|2. Is capable of filtering rows from just relational sources.
|2. Is capable of filtering rows originating from any kind of source system.
|3. It establishes a restriction on the number of row sets retrieved from a source.
|3. It restricts the number of rows delivered to a destination.
|4. It improves performance by reducing the number of rows mapped.
|4. It is inserted near the source to ensure that undesirable data is filtered out early and performance is maximized.
|5. In this case, the filter condition executes normal SQL in the database.
|5. It creates a condition that may be TRUE or FALSE utilizing statement or transformation function.
Question 2). How to delete duplicate records in Informatica? What are the different methods for doing this?
There are many methods for removing duplicates:
1. If the source database contains duplicates, the user may utilize the property in the source qualifier. To begin, the user must approach the “Transformation tab” and choose the ‘Select Distinct’ option. Additionally, a user may do the same thing through SQL override. The user may go to the “Properties” and enter the separate query in the SQL query tab.
2. A user may use Aggregator to get unique data by specifying ports as the key. If a user wants to search for duplicates throughout the whole column, they should select all ports as a group by key.
3. Additionally, the user may utilize a Sorter with the Sort distinct attribute to get different values.
4. Duplicate data may also be identified and removed using expression and filter transformations. If data is not sorted, it must first be sorted.
5. When a property in a Lookup transformation is modified to utilize Dynamic cache, the transformation gains a new port. This cache is updated on a real-time basis when data is read. If a source has duplicate data, the user may search the Dynamic lookup cache, and the router will then pick just one unique record.
Question 3). Distinguish joiner from lookup transformation.
Following are some of the key differences between lookup and joiner transformations:
- We may alter the query in lookup, but not in joiner.
- While we may give a variety of operators in lookup, such as “>,>=,!=,” in joiner, just the “= ” (equal to ) operator is accessible.
- While we may limit the number of rows read from a relational database with a lookup override, we cannot do so with a joiner.
- In joiner, we could join tables using the following methods: Normal Connect, Master Outer, Detail Outer, and Full Outer Join. However, this option is not accessible in lookup.
Lookup works similarly to a database’s Left Outer Join.
Question 4). How could you optimize joiner transformation performance?
- When feasible, use joins in a database.
- This is not always feasible, for example, when combining tables from two distinct databases or flat file systems.
- To connect the tables in a database, build and use a pre-session stored procedure.
- To execute the join, use the Source Qualifier transformation.
- When possible, join sorted data
- Select the source having fewer rows as the master source for an unsorted Joiner transformation.
- Select the source with the fewest duplicate key values as the master source for a sorted Joiner transformation.
Now you are ready for scenario-based interview questions:
Question 5). Assume you’re using Informatica to execute a business intelligence operation that will take many days or weeks. During this time period, you may find yourself repeatedly need access to the same data. What are the different kinds of caches associated with Informatica’s lookup function?
- Uncached: No-cache is created during the lookup transformation. Rather than that, each record’s lookup and return values are done utilizing the lookup source.
- Cached: By setting the lookup transformation to establish a cache, we may restrict communication between the Informatica server and the lookup source to and from. As a consequence, the whole data from the search is cached, and all subsequent lookups are done against the caches.
- Persistent: While the lookup caches are removed automatically after successful sessions, they may be set to preserve the caches for subsequent usage.
- Shared: The lookup cache may be used by several transformations. Between transformations in the similar mapping, unnamed caches may be shared. Named caches may include transformations that are shared across many mappings.
Question 6). Our Informatica data warehouse manages a huge amount of data and receives numerous ETL data sources. This, however, results in a bottleneck in some cases, lowering our overall efficiency. How would you resolve this and enhance the usefulness of our Informatica resource overall?”
Partitioned sessions are an effective method to alleviate bottlenecks and boost productivity. This approach is successful because it optimizes the server’s functionality, operations, and overall efficiency. Additionally, it contains periods of solo implementation throughout the session.
Question 7). Consider the following scenario: you have an unrelated lookup in Informatica and want to apply several input parameters to it. Give a specific example of how you’d go about doing that.
An unconnected lookup may be performed using an array of arguments. Each lookup will return the same result.
Question 8). Consider yourself as the company’s representative at our annual technology conference. The conference attracts attendees from around the nation, all of whom have varying degrees of expertise in data and data management. How would you define corporate data warehousing in layman’s terms?
I will use straightforward language, eliminate technical jargon, and provide examples, as follows. Enterprise data is critical to businesses. Typically, this data is stored in several locations across the company. For instance, client information may be stored in a customer relationship management system (CRM), whereas transactional data may be stored in a private accounting database. A data warehouse is a kind of platform technology that consolidates data from many sources into a single location where it can be examined to provide business intelligence insights.
Question 9). Consider that you are working with Informatica on a big data project and need the ability to filter rows from multiple data sources. How would you classify the use of filter transformations vs source qualifiers? Which would you prefer?
The critical distinction between source qualifiers and filter transformation is that filter transformation include the following characteristics:
- Reduce the number of rows delivered to a destination
- Allows for the filtering of rows from any kind of system
- Rows from mapped data may be filtered
- Define a condition; return a value of true or false.
- Source qualifications include the following characteristics:
- Restriction on the number of row sets retrieved from the source
- Can only be used to filter rows from a relational database.
- When reading the date from the source, this function filters the rows.
- The filter condition is written in normal SQL.
In this case, filter transformations make the most sense.
Question 10). Which situation would result in the Informatica server rejecting files?
When the server’s update strategy transformation is rejected, it regrets the files. Additionally, the database containing the information and data is disturbed. This is a very uncommon occurrence.
Question 11). How may the joiner condition’s performance be improved?
Several easy measures may be taken to improve the joiner condition’s performance:
Whenever feasible, data should be sorted prior to applying for membership.
Users should execute joins wherever feasible, and if this is not possible for certain tables, the user should construct a stored procedure to join the tables in the database.
When data is unsorted, the master source should be a source with fewer rows.
A source with fewer duplicate essential values should be regarded as a master source for sorted joiner transformations.
Question 12). What do you mean when you refer to corporate data warehousing?
Corporate data warehousing is the process of centralizing an organization’s data in a single location. Because the server is connected to a single source, data is always accessible and displayed via this one source. Additionally, it includes a periodic examination of the source.
The best preparation for an informatics scenario-based interview is to go over the questions in this guide to ensure you have a solid grasp of the topic. Additionally, you should dress professionally and be prepared to answer each topic in an approachable yet professional manner. Additionally, you can ensure that you really are competent and knowledgeable about the following subjects:
- Managing manufacturing failures
- Informatica design
- Managing exceptions and errors
- Informatica’s use of flat files
- Using Informatica mappings to implement SCDs