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At the time of Informatica PowerCenter installation, can you please let us know what all components are installed?
The following components are installed while installing Informatica power center:
1. PowerCenter clients
2. Integration services
3. Repository service
4. PowerCenter Domain
5. Administration console for PowerCenter
Q.What is the main use of stored procedure transformation?
ANSWER: The main use of stored procedure transformation is because it is a vital tool for maintaining and populating databases within the environment.
Q.Explain what is the difference between static cache and dynamic cache?
It decreases the performance and productivity when compared to static cache
Static cache is a process where it just inserts the data all the time. It doesn’t matter how many times the data is coming through, all it cares about is just inserting the data.
Q.Explain where we can find the throughput option in Informatica?
ANSWER: The throughput option is found in Informatica workflow monitor.
Within the workflow monitor, right click on the session, then click on the run properties.
Under source/target statistics we can find the throughput option.
What is the main use of target designer in Informatica?
ANSWER: With the help of target designer, we will be able to create Target definition.
Q.Define what do you mean by worklet?
ANSWER: A group of workflow tasks accumulated in a set is nothing but classified as a “worklet”. Within the workflow tasks, the following are included:
4. Event wait
Q.What is the full form of OLAP and define what is an OLAP?
ANSWER: OLAP stands for Online Analytical Processing.
It is defined as a method in which multidimensional analysis occurs.
Can you name at least one alternative tool for scheduling processes other than workflow manager?
Control M is an alternative tool for scheduling processes other than workflow manager pmcmd.
What are the different tools in workflow manager?
The different tools available in workflow manager are:
1. Task designer
2. Task developer
3. Workflow designer
Q.Define what do you mean by a workflow?
ANSWER: Workflow can be defined as a set of instructions which are intended to communicate to the server and letting it know on how to implement the tasks.
Q.Define what is user-defined event?
ANSWER: user-defined event is nothing but a flow of tasks in the workflow process.
These events can be created and raised as on when there is a need associated with it.
Q.What is a predefined event?
ANSWER: As the name itself suggests that the event is predefined.
It is nothing but a file watch event. Within this process, it will wait for a certain file to arrive at a specific location.
Q.What is the use of standalone command task?
ANSWER: The standalone command task can be used anywhere within a workflow process to execute the shell commands.
Q.Define what is a session task?
ANSWER: A session task is defined as a bunch of instructions which are guided towards a power center server which ultimately defines when to transfer the data from source to the targets.
Q.What are the prerequisites tasks that are needed to achieve the session partition?
ANSWER:If you have to do the session partition then you need to start configuring the session to partition to source data and then you have to install Informatica server machine in different CPu. I.e. multifold CPU’s.
Q.Define what is a surrogate key?
ANSWER: A surrogate key is nothing but a replacement of the primary key within the database.
It is considered to be a unique identification factor for each row within a table.
It is very helpful because the primary key can change and thus makes it difficult process to update the data, but not with the surrogate key.
A surrogate key is always in the form of a digit or an integer.
Q.What does the update strategy actually mean and what are the different options available for it?
ANSWER:Within Informatica, the data is processed based on row by row.
Within the target table, every row is inserted and it is marked as a default one.
The use of update strategy is done only when there is a need to update a single row or insert a row based on a sequence defined.
Within the update strategy, we need to mention the condition so that the specified row in the update strategy can be processed and the row can be actually marked as per the condition, i.e. updated or inserted.
Q.Can you briefly define what is a reusable transformation?
ANSWER: The reusable transformation concept is widely used in mappings.
Reusable transformation is different to that of other mappings where they use transformations as it stores as a metadata.
Whenever there is a change in the reusable transformation, the transformation will be nullified in the mappings.
Q.Define what is a mapplet?
ANSWER: A mapplet is nothing but a recyclable object which uses a mapplet designer.
Mapplet permits to reuse the transformation logic in different mappings.
A mapplet consists of a set of transformations.
Q.What are the types of loadings that are available in Informatica?
ANSWER: In Informatica, they are two types of loading:
1. Normal loading
2. Bulk loading
Normal loading is a process where the records are loaded one by one and it writes a log for the same. When compared to other types of loading normal loading the loading process takes time to the target source.
Bulk loading is a process where a set of records are loaded into the target database at once. When compared to normal loading process, bulk loading process takes very less time to load the data.
Q.Define what is aggregate cache in aggregator transformation?
ANSWER: The aggregator is nothing but a function which stores all the data in the aggregator cache until and unless it deals with all the aggregate calculations.
So when you are executing a session in which you are using an aggregator transformation, the Informatica server will automatically start creating indexes and data caches in the memory to accommodate and process the transformation.
It is a known fact that Informatica server needs more space, it stores the overflow values in all the cache files.
Q.Explain what is meant by a transformation? What are the different types of transformations available in Informatica?
ANSWER: The term transformation itself depicts the nature of the activity. It is a repository object where it generates, modifies and passes the data.
The following are different types of transformations that are available in Informatica:
1. Aggregator transformation
2. Expression transformation
3. Filter transformation
4. Joiner transformation
5. Lookup transformation
6. Normalizer transformation
7. Rank transformation
8. Router transformation
Q.What is the difference between active transformations and a passive transformation in Informatica? Give example transformations for each?
It is a process it changes the number of rows that have gone through the mapping. This process is called as Active transformation
Some of the Active transformations are:
It is a process where it doesn’t change the number of rows that have gone through the mapping. This process is called as Passive transformation.
Some of the Passive transformations are:
Sequence Generator transformation
External procedure transformation
Q.Explain what is target load order?
ANSWER: Target load order is nothing but a list of all activities where one can define the priority. Based on this priority the data will be loaded into the Informatica server.
If you have a list of source qualifiers connected to multiple targets then you can define the order or dictate an order to the Informatica server so that the data can be loaded into the targets.
Q.Explain to us whether two flat files can be joined together using Joiner Transformation? Explain what is joiner transformation means?
ANSWER: Yes, you can join two flat files together using joiner transformation.
Joiner transformation is an active and connected transformation where it is primarily used to join two sources of data. The source of data can be from one origin or it can be from two different origins
What are different types of dimensions that are available in Informatica?
They are three types of dimensions that are available:
1. Junk dimension
2. Degenerative dimension
3. Conformed dimension
Q.Explain what are slowly changing dimensions? What are the different types of slowly changing dimensions that are available?
ANSWER:Slow changing dimensions are those where the dimensions are meant to be changed in over time. The slow changing dimensions are noted as SCD.
They are three different types of slowly changing dimensions, they are:
1. Slowly changing dimension-Type 1: In this type of SCD it has only current records
2. Slowly changing dimension-Type 2: In this type of SCD it has both current records and also historical records
3. Slowly changing dimension-Type 3: In this type of SCD it has current records plus one previous record
Q.Explain what is a parameter file and define what are the different values that are available in a parameter file?
ANSWER: A parameter file is nothing but a file which is created in a text editor or a word pad. The following different values can be defined in a parameter file, they are:
1. Mapping parameters
2. Mapping variables
3. Session parameters
Q.What is a connected Lookup?
ANSWER: 1. The connected lookup is a lookup which participates in all the data flows and it is capable of receiving inputs directly from the pipeline itself.
2. Within connected lookup can be used within both dynamic cache and static cache.
3. Within connected lookup, it caches all lookup columns
4. The connected lookup will support user-defined values
Q.What is the difference between a mapplet in PowerCenter and a mapplet in the Developer tool?
ANSWER: 1. Mapplet in PowerCenter and in the Developer tool is a reusable object that contains a set of transformations. You can reuse the transformation logic in multiple mappings.
2. PowerCenter mapplet can contain source definitions or Input transformations as the mapplet input. It must contain Output transformations as the mapplet output.
3. Developer tool mapplet can contain data objects or Input transformations as the mapplet input. It can contain data objects or Output transformations as the mapplet output.
A mapping in the Developer tool also includes the following features:
1. You can validate a mapplet as a rule.
2. You use a rule in a profile.
3. A mapplet can contain other mapplets.
Q.What is the difference between a mapplet and a rule?
ANSWER:You can validate a mapplet as a rule. A rule is business logic that defines conditions applied to source data when you run a profile. You can validate a mapplet as a rule when the mapplet meets the following requirements:
1. It contains an Input and Output transformation.
2. The mapplet does not contain active transformations.
3. It does not specify cardinality between input groups.
Q.What is the difference between a source and target in PowerCenter and a physical data object in the Developer tool?
ANSWER: In PowerCenter, you create a source definition to include as a mapping source. You create a target definition to include as a mapping target. In the Developer tool, you create a physical data object that you can use as a mapping source or target.
Q.What is the difference between the PowerCenter Repository Service and the Model Repository Service?
ANSWER: The PowerCenter application services and PowerCenter application clients use the PowerCenter Repository Service. The PowerCenter repository has folder-based security. The other application services, such as the Data Integration Service, Analyst Service, Developer tool, and Analyst tool, use the Model Repository Service. The Model Repository Service has project-based security. You can migrate some Model repository objects to the PowerCenter repository.
Q.What is an unconnected lookup?
ANSWER: The unconnected lookup is entitled to receive input values from the result of LKP
With unconnected lookup, it can only return one column value The unconnected lookup does not really support user-defined default values
Q.What is the difference between the Power Center Integration Service and the Data Integration Service?
ANSWER: The Power Center Integration Service is an application service that runs sessions and workflows.
The Data Integration Service is an application service that performs data integration tasks for the Analyst tool,the Developer tool, and external clients. The Analyst tool and the Developer tool send data integration task requests to the Data Integration Service to preview or run data profiles, SQL data services, and mappings. Commands from the command line or an external client send data integration task requests to the Data Integration Service to run SQL data services or web services.
Q.What is the difference between the PowerCenter Repository Service and the Model Repository Service?
ANSWER: The PowerCenter application services and PowerCenter application clients use the PowerCenter Repository Service. The PowerCenter repository has folder-based security.
The other application services, such as the Data Integration Service, Analyst Service, Developer tool, and Analyst tool, use the Model Repository Service. The Model Repository Service has project-based security.
You can migrate some Model repository objects to the PowerCenter repository.