Informatica Interview Questions Part – II
75. What are the Direct and Indirect methods in the Flat file extraction?
In the direct method the extract the flat file by using its own meta data. In indirect method we extract all the flat files by using one flat file’s meta data.
76. What is the Maplet?
Mapplet is type of meta data object which contains set of reusable transformation logic which can be reused in multiple mapping. A maplet contains one maplet input Transformation and one maplet output Transformation.
77. What is the basic difference between reusable transformation and mapplet?
Maplets are set of reusable transformation logic and reusable transformations are created by single transformation logic.
78. What is Target Load Plan?
The Target Load plan is the order in which we should load the target to implement the Data Acquisition Process.
79. What is Constraint Based Load ordering?
The Constraint Based Load ordering specified the loading of the dimensions tables based on the constraints designed in the dimension table. The Constraint Based Load order is used for implementing snow-flake schema data loading.
80. What is File Watch Event?
The Event Wait activity of a session has event called as File Watch which will watch wether the file is copied or not.
81. What is worklet?
The worklet is a group of sessions. To execute the worklet we have to create the workflow.
82. Why we use stored procedure transformation?
For populating and maintaining databases.
83. Why we use partitioning the session in Informatica?
Partitioning achieves the session performance by reducing the time period of reading the source and loading the data into target.
84. Why we use lookup transformation?
Look up Transformations can access data from relational tables that are not sources in mapping. With Lookup transformation, we can accomplish the following tasks.
85. Which transformation should we use to normalize the COBOL and relational sources?
When you drag the COBOL source into the Designer workspace, the normalized transformation automatically appears, creating input and output ports for every column in the source.
86. What are the types of data that passes between Informatica server and stored procedure?
There are three types of data
- Input/output parameter
- Return Values
- Status code
87. What are the groups available in Router Transformation?
- User defined group
- Default group
88. What are join types in Joiner Transformation?
The joins supplied by the Joiner Transformation are:
- Normal Join
- Master Outer Join
- Detail Outer Join
- Full Outer Join
89. What are the designer tools available for creation of Transformations?
- Mapping Designer
- Transformation Developer
- Mapplet Designer
90. What are the basic needs to join two sources in Source Qualifier?
The two source tables should have a primary key – foreign key relationship and the two source tables should have matching data types.
91. What is a Status code?
Status code provides error handling facility during the session execution.
92. What is Data Driven?
The Data Driven is the instruction which is fed to Informatica Server whether to insert/delete/update when using Update Strategy Transformation.
93. What are the tasks to be done to partition a session?
- Configure the session to partition the source data
- Install the Informatica on a machine with multiple CPU
94. In which circumstances the Informatica creates a reject file (bad file)?
When it encounters the DD_REJECT in Update strategy Transformation
Voilets database constraints file in the rows was truncated or overflowed.
95.In a sequential batch can you run the session if previous session fails?
Yes, by setting the option always runs the session.
96. How many ways your create ports?
- Drag the prot from another transformation
- Click the add button on the ports tab.
97.How can you improve session performance in aggregator transformation?
Use sorted input.
98. Can you use the mapping parameters or variables created in one mapping into any other reusable transformation?
Yes, because reusable transformation is not contained with any mapplet or mapping.
99. Can you use the mapping parameters or variables created in one mapping into another mapping?
We can use mapping parameters or variables in any transformation of the same mapping or mapplet in which you have created mapping parameters or variables.
100. Can you start a session inside a batch individually?
We can start our required session only in case of sequential batch in case of concurrent batch. We can do like this.
101. Can you start batches with in a batch?
You cannot. If you wants to start batch that resides in a batch, create a new independent batch and copy the necessary sessions into the new batch.
102. Can you generate reports in Informatica?
Yes. By using Metadata reporter we can generate reports in Informatica.
103. After dragging the ports of three sources(sql server, oracle, Infomix) to a single source qualifier, can you map these three ports directly to target?
No, different source types cannot be joined in SQ.
104. What are Target Types on the Server?
Target Types are File, Relational and XML.
105.What is the aggregate transformations?
Aggregate transformation allows you to perform aggregate calculations, such as averages and sums.
106. How do you identify existing rows of data in the target table using lookup transformation?
Can identify existing rows of data using Unconnected transformation.
107. What is Code Page used for?
Code page is used to identify characters that might be I different languages. If your are importing Japanese data into mapping, you must select the Japanese code page of source data.
108. What is a source qualifier?
It represents all data queried from the source.
109. Where should you place the flat file to import the flat file definition to the designer?
Place it in Local folder.
110. What are the settings that you use to configure the joiner transformation?
- Master and detail source
- Type of join
- Condition of the join
111. What are the session parameters?
Session parameters are like mapping parameters; represent values you might want to change between Sessions such as database connections or source files.
112. What are the methods for creating reusable transformations?
There are two methods:
- Design it in the transformation developer.
- Promote a standard transformation from mapping designer. After you ass a transformation to the mapping, you can promote it to the status of reusable transformation.
113. What are the joiner caches?
When a Joiner transformation occurs in a session, the Informatica Server reads all the records from the master source and builds index and data caches bases on the master rows. After building the caches, the Joiner transformation reads records from the detail source and performs joins.
114. What are different options uses to configure the sequential batches?
There are two options:
- Run the session only if previous session completes successfully.
- Always runs the session.
115. What are the data movement modes in Informatica?
Data movement modes determine how Informatica server handles the character data. You chooses the data movement in the Informatica server configuration settings Two types of data movement modes available in Informatica.
- ASCII mode
- Uni code mode
116. To achieve the session partition what are the necessary tasks you have to do?
- Configure the session to partition source data.
- Install the Informatica server on a machine with multiple CPU’S
117. Performance tuning in Informatica?
The goal of performance tuning is optimize session performance so sessions run during the available load window for the Informatica server.
118.When can session fail?
The session fails when,
- Server cannot allocate enough system resources
- Session exceeds the maximum no. of sessions
- Server cannot obtain an execute lock for the session
- Server encounters database errors
- Network related errors
119. How many ways you can create a Reusable Transformation?
There are two ways to create a Reusable Transformation
- By designing it in the transformation developer
- By promoting the already existing Transformation to reusable from its properties.
120. What is a aggregator cache in aggregate transformation?
The aggregator transformation stores the data in the aggregator cache until it completes aggregate calculations.
121. What is data cache and Index cache?
When you use aggregator transformation in your mapping then Informatica server creates Data and Index cache in memory to process the transformation.
122. What is a Mapping Variable?
A Mapping Variable represents a value that can change throughout the session. The Informatica server saves the value of mapping variable in repository in the end of the session and uses it for the next session run.
123. In which scenario does the Update Strategy Transformation is best suited?
Within a session: When you configure a session, you can instruct the Informatica server to either treat all records in same way (treat all as insert/treat all as update/treat all as update) or use instructions coded into the session to flag records for different database operations.
Within a Mapping: Within a mapping, you use the update strategy transformation to flag records for insert, update or reject.
124. What are the types of mappings in Getting Started Wizard?
- Simple pass through mapping: loads a slowly growing fact or dimension table be inserting new rows. Use this map to loading new data into it.
- Slowly growing target: Loads a slowly growing fact or dimension table be inserting new rows. Use this map to load new data without disturbing the existing data.
125. How can you recognize whether or not the data is added in the table in Type – II dimension?
- By version number
- By flag value
- By effective date range
126. Why you use Repository connectivity?
When you edit or schedule the session each time, Informatica server directly communicates the repository to check whether or not the session and users are valid.
127. What are the data movement modes in Informatica?
The data movement modes determines how Informatica server handles the character data. There are two types of data movement modes:
- ASCII mode
- Uni code mode
128. Can you copy the session to a different folder or Repository?
Yes. By using the copy session wizard you can copy a session in a different folder or Repository. But first you should copy the mapping of that session before you copy session.
129. What is the difference between partitioning of relational target and partitioning of file target?
If you partition a session with a relational target Informatica server creates multiple connections to the target database to write target data concurrently. If you partition a session with file target the Informatica server create one target file for each partition.
130. What are the Transformations that restrict the partition of sessions?
- Advanced External Transformation
- External Procedure Transformation
- Aggregator Transformation
- Joiner Transformation
- Normalizer Transformation
- XML Targets
131. What is a Power Center Repository?
The Power Center Repository allows you to share metadata across repositories to create a data mart domain. In a data mart domain, you can create a single global repository to store metadata used across an enterprise and a number of local repositories to share the global metadata as needed.