Showing posts with label ETL TESTING Interview Questions with Answers. Show all posts
Showing posts with label ETL TESTING Interview Questions with Answers. Show all posts

Friday, 11 September 2015

50 [UPDATED] ETL TESTING Interview Questions and Answers pdf

50 TOP ETL TESTING Interview Questions with Answers pdf :-

 
1.What is ETL?


2.What are the operations for ETL testing?


3. What is OLAP?


4. What is OLTP?


5. What are Dimensions?


6. What are Confirmed Dimensions?


7. What are Fact Tables?


8.  What are the types of Facts?


9. What are the types of Fact Tables?


10. What is Grain of Fact?
ETL TESTING Interview Questions and Answers pdf
ETL TESTING Interview Questions

11. What is Factless Fact table?


12. What are Measures?


13. What are Cubes?


14. What are Virtual Cubes?


15. What is a Star schema design?


16. What is Snow Flake schema Design?


17. What is Operational Data Store [ODS] ?


18. What is Denormalization?


19. What is Surrogate Key?


20. What are the client components of Informatica 7.1.1?


21. What are the server components of Informatica 7.1.1?


22. What is Metadata?


23. What is a Repository?


24. What is Data Acquisition Process?


25. What are the GUI based ETL tools?


26. What are programmatic based ETL tools?


27.  What is a Transformation?


28. What are the various tools? Name a few?


29. What are features of Informatica Repository Server?


30. What is a Work Flow?


31. What is the uses of Lookup Transformation?


32. What are the different sources of Source systems of Data Warehouse?


33. Types of Slowly Changing Dimensions:


34. What are Update Strategy’s target table options?


35. What does a Mapping document contains?


36. What does the Top Down Approach says?


37. What does the Bottom Up Approach or Ralph Kimball Approach says?


38. Who is the first person in the organization to start the Data Warehouse project?


39. What is a Dimension Modeling?


40. What are the types of OLAPs ?


41. What is worklet?


42. Why we use lookup transformation?


43. What is a Power Center Repository?


44. What are snapshots? What are materialized views & where do we use them? What is a materialized view?


45. Where do we use connected and un connected lookups?


46. What is a Data Warehouse?


47. What are the Advantages of Data warehousing?


48. What is a Data mart?


49.In what way ETL testing is beneficial?  


50.What Tools are mostly used in ETL and report testing?

30 [UPDATED] ETL TESTING Multiple Choice Questions and Answers pdf free download

 ETL TESTING Multiple Choice Questions and Answers :-


****50 [MY EXPERIENCE] ETL TESTING Interview Questions and Answers pdf****CLICK HERE


1. All data in flat file is in this format.
A.    Sort
B.      ETL
C.     Format
D.      String
Ans:  D

2. It is used to push data into a relation database table. This control will be the destination for most fact table data flows.
A.   Web Scraping
B.     Data inspection
C.     OLE DB Source
D.    OLE DB Destination
Ans:  D

3. Logical Data Maps
A.   These are used to identify which fields from which sources are going to with destinations. It allows the ETL developer to identify if there is a need to do a data type change or aggregation prior to beginning coding of an ETL process.
B.   These can be used to flag an entire file-set that is ready for processing by the ETL process. It contains no meaningful data bu the fact it exists is the key to the process.
C.  Data is pulled from multiple sources to be merged into one or more destinations.
D.  It is used to massage data in transit between the source and destination.
Ans:  A

4. Data access methods.
A.  Pull Method
B.   Push and Pull
C. Load in Parallel
D.  Union all
Ans:  B

5. OLTP
A.   Process to move data from a source to destination.
B.   Transactional database that is typically attached to an application. This source provides the benefit of known data types and standardized access methods. This system enforces data integrity.
C.  All data in flat file is in this format.
D. This control can be used to add columns to the stream or make modifications to data within the stream. Should be used for simple modifications.
Ans:  B

6. COBOL
A.  Process to move data from a source to destination.
B.   The easiest to consume from the ETL standpoint.
C.  Two methods to ensure data integrity.
D.   Many routines of the Mainframe system are written in this.
Ans:  D

7. What ETL Stands for
A.   Data inspection
B.    Transformation
C.   Extract, Transform, Load
D.   Data Flow
Ans:  C

8. The source system initiates the data transfer for the ETL process. This method is uncommon in practice, as each system would have to move the data to the ETL process individually.
A.  Custom
B.   Automation
C.  Pull Method
D.  Push Method
Ans:  D

9. Sentinel Files
A.  These are used to identify which fields from which sources are going to with destinations. It allows the ETL developer to identify if there is a need to do a data type change or aggregation prior to beginning coding of an ETL process.
B.   These can be used to flag an entire file-set that is ready for processing by the ETL process. It contains no meaningful data bu the fact it exists is the key to the process.
C.    ETL can be used to automate the movement of data between two locations. This standardizes the process so that the load is done the same way every run.
D.   This is used to create multiple streams within a data flow from a single stream. All records in the stream are sent down all paths. Typically uses a merge-join to recombine the streams later in the data flow.
Ans:  B

10. Checkpoints
A.  Similar to "break up processes", checkpoints provide markers for what data has been processed in case an error occurs during the ETL process.
B.   Similar to XML's structured text file.
C.  Many routines of the Mainframe system are written in this.
D.  It is used to import text files for ETL processing.
Ans:  A
ETL TESTING Multiple Choice Questions and Answers pdf free download
11    Mainframe systems use this. This requires a conversion to the more common ASCII format.
A.     ETL
B.      XML
C.     Sort
D.     EBCDIC
Ans:  D

12      Ultimate flexibility, unit testing is available, usually poor documentation.
A.     ETL
B.     Custom
C.     OLTP
D.     Sort
Ans:  B

13      Conditional Split
A.  Many routines of the Mainframe system are written in this.
B.    Data is pulled from multiple sources to be merged into one or more destinations.
C.    It allows multiple streams to be created from a single stream. Only rows that match the criteria for a given path are sent down that path.
D.    This is used to create multiple streams within a data flow from a single stream. All records in the stream are sent down all paths. Typically uses a merge-join to recombine the streams later in the data flow.
Ans:  C

14     Flat files
A.  The easiest to consume from the ETL standpoint.
B.    Three components of data flow.
C.   Three common usages of ETL.
D.    Two methods to ensure data integrity.
Ans:  A

15     This is used to create multiple streams within a data flow from a single stream. All records in the stream are sent down all paths. Typically uses a merge-join to recombine the streams later in the data flow.
A.  OLTP
B.    Mainframe
C.   EBCDIC
D.   Multicast
Ans:  D

16       There are little to no benefits to the ETL developer when accessing these types of systems and many detriments. The ability to access these systems is very limited and typically FTP of text files is used to facilitate access.
A.  Mainframe
B.    Union all
C.   File Name
D.  Multicast
Ans:  A

17    Shows the path to the file to be imported.
A.  File Name
B.   Mainframe
C.  Format
D.  Union all
Ans:  A

18    Wheel is already invented, documented, good support.
A. Format
B.   COBOL
C. Tool Suite
D.  Flat files
Ans:  C

19     Similar to XML's structured text file.
A.  Data Scrubbing
B.     EBCDIC
C.    String
D.   Web Scraping
Ans:  D

20    Flat file control
A.  Three components of data flow.
B.    It is used to import text files for ETL processing.
C.   The easiest to consume from the ETL standpoint.
D.   Shows the path to the file to be imported.
Ans:  B

21    Two methods to ensure data integrity.
A.    Sources, Transformation, Destination
B.    Data inspection
C.   Row Count Inspection, Data Inspection
D.   Row Count Inspection
Ans:  C

22    Transformation
A.    Data is pulled from multiple sources to be merged into one or more destinations.
B.      It is used to import text files for ETL processing.
C.     Process to move data from a source to destination.
D.     It is used to massage data in transit between the source and destination.
Ans:  D

23    Three common usages of ETL.
A.  Data Scrubbing
B.    Sources, Transformation, Destination
C.     Merging Data
D.    Merging Data, Data Scrubbing, Automation
Ans:  D

24     Load in Parallel
A.  A value of delimited shou;d be selected for delimited files.
B.    Data is pulled from multiple sources to be merged into one or more destinations.
C.  This will reduce the run time of ETL process and reduce the window for hardware failure to affect the process.
D.  this should be check if column name have been included in the first row of the file.
Ans:  C

25   This can be computationally expensive excluding SSD.
A. Hard Drive I/O
B.   Mainframe
C.  Tool Suite
D. Data Scrubbing
Ans:  A

26   A value of delimited shou;d be selected for delimited files.
A.  Sort
B.   Format
C.  String
D.  OLTP
Ans:  B

27   this should be check if column name have been included in the first row of the file.
A.   Row Count Inspection, Data Inspection
B.    Format of the Date
C.   Column names in the first data row checkbox
D.     Do most work in transformation phase
Ans:  C

What are the Advantages of Data warehousing?

1.Maintaining a data warehouse have plenty of benefits which include:
2.Integration of data gathered from various sources
3.Beneficial for short term as well as long term businesses
4.Improves customer satisfaction
5.Easy access to the end users
6.Offers considerably accurate and comprehensive data
7.Integrates internal and external data as well
8.Timely access to the corporate data

In what way ETL testing is beneficial?

Provides data security
Offers accuracy in data
Reporting efficiency
Loss of data is minimal

What Tools are mostly used in ETL and report testing?

For ETL:
Informatica
Data stage
Oracle ware house builder
Abinito
Hyperion
Python

For Reporting:

Microstrategy
Business objects
Siebel analytics
Cognos

Where do we use connected and un connected lookups?

If return port only one then we can go for unconnected. More than one return port is not possible with Unconnected. If more than one return port then go for Connected.
If you require dynamic cache i.e where your data will change dynamically then you can go for connected lookup. If your data is static where your data won't change when the session loads you can go for unconnected lookups

What are snapshots? What are materialized views & where do we use them? What is a materialized view?

Materialized view is a view in which data is also stored in some temp table.i.e if we will go with the View concept in DB in that we only store query and once we call View it extract data from DB. But In materialized View data is stored in some temp tables.

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.

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.

What is worklet?

The worklet is a group of sessions. To execute the worklet we have to create the workflow.

What are the types of OLAPs ?

DOLAP: The OLAP tool which words with desktop databases are called as DOLAP. Example: Cognos EP 7 Series and Business Objects, Micro strategy.

ROLAP:
The OLAP which works with Relational databases are called as ROLAP. Example: Business Object, Micro strategy, Cognos ReportNet and BRIO.

MOLAP: The OLAP which is responsible for creating multidimensional structures called cubes are called as MOLAP. Example: Cognos ReportNet.

HOLAP: The OLAP which uses the combined features of ROLAP and MOLAP are called as HOLAP. Example Cognos ReportNet.

What is a Dimension Modeling?

A Dimensional Modeling is a high level methodology used to implement the start schema structure which is done by the Data Modeler.

Who is the first person in the organization to start the Data Warehouse project?

The first person to start the Data Warehouse project in a organization is Business Analyst.

What does the Bottom Up Approach or Ralph Kimball Approach says?

The Bottom Down Approach is coined by Ralph Kimball. According to his approach he says “First we need to develop subject oriented database called as “Data Marts” then integrate all the Data Marts to develop the Enterprise data warehouse.

What does the Top Down Approach says?

The Top Down Approach is coined by Bill Immon. According to his approach he says “First we need to implement the Enterprisedata warehouse by extracting the data from individual departments and from the Enterprise data warehouse develop subject oriented databases called as “Data Marts”.

What does a Mapping document contains?

The Mapping document contains the following information :
Source Definition – from where the database has to be loaded
Target Definition – to where the database has to be loaded
Business Logic – what logic has to be implemented in staging area.

What are Update Strategy’s target table options?

Update as Update: Updates each row flagged for update if it exists in the table.
Update as Insert: Inserts a new row for each update.
Update else Insert: Updates if row exists, else inserts.

Types of Slowly Changing Dimensions

Type – 1 (Recent updates)
Type – 11 (Full historical information)
Type – 111 (Partial historical information)

What are the different sources of Source systems of Data Warehouse?

1.RDBMS
2.Flat Files
3.XML Files
4.SAP R/3
5.PeopleSoft
6.SAP BW
7.Web Methods
8.Web Services
9.Seibel
10.Cobol Files
11.Legacy Systems.

What is the uses of Lookup Transformation?

The Lookup Transformation is useful for:

1.     Getting a related value form a table using a key column value
2.     Update slowly changing dimension table
3.     To check whether records already exists in the table.