1. What is Enterprise Data Warehousing?
A: Enterprise Data Warehousing is the creation of organization data at a single access point. Data with global view can be given to the server through one single source store which can be analyzed periodically. This provides better results even though it takes a longer time.
2. How are data warehouse, database, and data mart different?
A: Database is a collection of similar type of data arranged in a specific way. Data warehouse is a collection of different types of data larger in size than a database from which they can be taken according to need. Data mart is also a set of different types of data covering the different aspects of the organization.
3. What is domain?
A: All interconnected relationships and nodes which are handled by one single organization point constitute the domain.
4. How are repository server and powerhouse different?
A: Repository server serves to control the entire repository of charts, tables, etc. to ensure the integrity and uniformity of the repository. The powerhouse server manages the working of the different processes among the members of the database repository of the server.
5. What is meant by Lookup Transformation?
A: Lookup Transformation is a system of locating a source qualifier, source, or target to retrieve relevant data. Multiple Lookup Transformations can be used in a single mapping.
6. Informatica allows creation of how many repositories?
A: As many repositories as wanted can be created in Informatica depending on the number of ports.
7. What is meant by Partitioning a Session?
A: Partitioning a Session is the implementation of unit sequences in a session. It improves the working and efficiency of the server.
8. What are Sessions in Informatica?
A: A Session is a teaching set which has to be implemented so that data may be converted from source to target.
9. What is batch in Informatica?
A: A batch is a system of combining executions of sessions in serial or in parallel.
10. How many sessions may be grouped in a batch?
A: Lower number of sessions in a batch eases the migration process, but there is no limit to the number of sessions that can be included in a batch.
11. How are mapping parameter and mapping variable different?
A: Mapping variables are values that can change while the session is implemented, while mapping parameters do not change during session implementation. Mapping parameters get values assigned to them at the beginning of the session. Mapping variable values are stored in memory at session end and retrieved again when session restarts.
12. What does the aggregator cache file do?
A: When extra memory is required, the aggregator supplies extra cache files to store the transformation values. They also store transitional values from the local buffer memory.
13. What is meant by role playing dimension?
A: Dimensions that play various roles while staying within the same database domain are known as role playing dimensions.
14. How are repository reports accessed without the help of SQL or some other transformation?
A: Repository reports may be accessed with metadata reporter, and SQL or other transformations are not required.
15. Which types of metadata can be stored in repository?
A: Mappings, Mapplet, Source definition, Target definition, and Transformations are the types of metadata that may be stored in the repository.
16. What is meant by code page compatibility?
A: Code page compatibility is the system that governs transfer of data from one code page to another without any loss. Transfer without data loss is possible only if both pages have the same set of characters, when the code pages are fully compatible.
17. What is meant by Expression Transformation?
A: Expression transformation allows non aggregate calculation of values in a single row before being written on target.
18. What is meant by Aggregator Transformation?
A: Aggregator Transformation allows calculation of aggregates, like sums, averages, etc.
19. What is meant by Filter Transformation?
A: Filter transformation is a system to filter through the rows during mapping under certain filter conditions. All the input and output ports are present in the transformation and only the rows meeting the condition can pass through the filter.
20. What is meant by Joiner Transformation?
A: Joiner transformation is the system to combine two connected but heterogeneous sources present at different locations.
21. What is meant by Source Qualifier Transformation?
A: The source qualifier transformation is a system of joining data that comes out of a common source.
22. How are connected and unconnected look up different?
A: Connected lookup is the transformation system where inputs are directly taken from other transformations already in the pipeline. Unconnected lookup does not draw inputs from other pipeline transformations, but they may be raised by LKP expressions as functions and may be used in any transformation.
23. What is meant by mapplet?
A: Mapplet is a recyclable object using mapplet designer. It contains a set of transformations and allows the use of transformation logic in multiple mappings.
24. What is meant by Reusable Transformation?
A: Reusable transformations are those that are used many times during mapping. They are stored as metadata and are different from other mappings using the transformation.
25. What is meant by Surrogate Key?
A: Surrogate Keys are digits or integers serving as unique identities for every row in the table. It serves as a replacement for the natural Prime Key which may change making updates difficult.
26. What is meant by a session task?
A: Session task is a set of instructions to guide the Power Center server on when and how to carry out data transfer from the source to the target.
27. What is meant by Command Task?
A: The Command Task is a set of instructions that allows running of one or more DOS in Windows or shell commands in UNIX during a workflow.
28. What is meant by workflow?
A: The workflow is a complete set of instructions to dictate methods of implementing tasks to the server.
- Can we do override if it is a flat file?
- Do I have to fetch 5th record from the bottom? (what's the command in Unix?)
- When to use rename, replace, reuse and skip conflicts during code migration?
- How will you handle sequence generator during code migration? Explain?
- Complex mapping in your project what you have done in this?
- What is the use deadlock in informatica?