Q1 : What is a command that used to run a batch?
A : pmcmd is used to start a batch.
Q2 : What is power center repository?
A : The PowerCenter repository allows you to share metadata across repositories to create a data mart domain.
Q3 : What is the Data Transformation Manager(DTM)?
A : After the load manager performs validations for the session, it creates the DTM process. The DTM process is the second process associated with the session run.
Q4 : What is Lookup transformation?
A : Lookup transformation is Passive and it can be both Connected and UnConnected as well. It is used to look up data in a relational table, view, or synonym. Lookup definition can be imported either from source or from target tables.
Q5 : How can you define a transformation?
A : A transformation is a repository object that generates, modifies, or passes data. The Designer provides a set of transformations that perform specific functions.
Q6 : Is lookup an active or passive transformation?
A : From Informatica 9x, Lookup transformation can be configured as “Active” transformation.
Q7 : Why is Sorter an Active Transformation?
A : This is because we can select the “distinct” option in the sorter property.
When the Sorter transformation is configured to treat output rows as distinct, it assigns all ports as part of the sort key. The Integration Service discards duplicate rows compared during the sort operation. The number of Input Rows will vary as compared with the Output rows and hence it is an Active transformation.
Q8 : What are the different lookup cache(s)?
A : Informatica Lookups can be cached or uncached (No cache). And Cached lookup can be either static or dynamic. A static cache is one which does not modify the cache once it is built and it remains same during the session run. On the other hand, A dynamic cache is refreshed during the session run by inserting or updating the records in cache based on the incoming source data. By default, Informatica cache is static cache.
Lookup cache can also be divided as persistent or nonpersistent based on whether Informatica retains the cache even after the completion of session run or deletes it.
Q9 : How can we update a record in target table without using Update strategy?
A : A target table can be updated without using ‘Update Strategy’. For this, we need to define the key in the target table in Informatica level and then we need to connect the key and the field we want to update in the mapping Target. In the session level, we should set the target property as “Update as Update” and check the “Update” check-box.
Q10 : What can we do to improve the performance of Informatica Aggregator Transformation?
A : Aggregator performance improves dramatically if records are sorted before passing to the aggregator and “sorted input” option under aggregator properties is checked. The record set should be sorted on those columns that are used in Group By operation.
Q11 : What is Update Strategy transformation?
A : Update strategy transformation is an active and Connected transformation. It is used to update data in target table, either to maintain history of data or recent changes. You can specify how to treat source rows in table, insert, update, delete or data-driven.
Q12 : What is fact table?
A : The centralized table in a star schema is called a fact table. Fact tables are three types
Additive non-additive semi-additive
Q13 : What is parameter file?
A : A parameter file is a file created by text editor such as word pad or notepad. U can define the following values in parameter file.
- Maping parameters
- Maping variables
- session parameters.
Q14 : Why we use stored procedure transformation?
A : A stored procedure transformation is an important tool for populating and maintaining databases.
Q15 : What is Rank transformation?
A : Rank transformation is an Active and Connected transformation. It is used to select the top or bottom rank of data.
Q16 : What is Joiner transformation?
A : Joiner Transformation is an Active and Connected transformation. This can be used to join two sources coming from two different locations or from same location.
Q17 : What is the difference between Active and Passive transformation?
A : Active Transformation: An active transformation can change the number of rows that pass through it from source to target i.e it eliminates rows that do not meet the condition in transformation.
Passive Transformation: A passive transformation does not change the number of rows that pass through it i.e it passes all rows through the transformation.
Q18 : What are Filter transformation?
A : Filter transformation is an Active and Connected transformation. This can be used to filter rows in a mapping that do not meet the condition.
Q19 : What is the maplet?
A : Maplet is a set of transformations that you build in the maplet designer and you can use in multiple mappings.
Q20 : What are Session and Batches?
A : Session:
A session is a set of commands that describe the server to move data to the target.
Batch:
A Batch is a set of tasks that may include one or more number of tasks (sessions, event wait, email, command, etc).