What is the difference between warehouse key and surrogate key?
- 1 Answers
- 6900 Views
- Accenture, I also Faced
- E-Mail Answers
Answer Posted / jaspreet banga
Surrogate key concept:- Surrogate keys are generated by
system and they identifies unique 'ENTITY'! yes its entity
and not record ,while primary key is used for finding
unique record.
Let me give you a simple classical example for surrogate
key:
On the 1st of January 2002 Employee 'E1' belongs to
Business Unit 'BU1' (that's what would be in your Employee
Dimension). This employee has a turnover allocated to him
on the Business Unit 'BU1' But on the 2nd of June the
Employee 'E1' is muted from Business Unit 'BU1' to Business
Unit 'BU2.' All the new turnover have to belong to the new
Business Unit 'BU2' but the old one should Belong to the
Business Unit 'BU1.'
If you used the natural business key 'E1' for your employee
within your datawarehouse everything would be allocated to
Business Unit 'BU2' even what actualy belongs to 'BU1.'
If you use surrogate keys you could create on the 2nd of
June a new record for the Employee 'E1' in your Employee
Dimension with a new surrogate key.
This way in your fact table you have your old data (before
2nd of June) with the SID of the Employee 'E1' 'BU1.' All
new data (after 2nd of June) would take the SID of the
employee 'E1' 'BU2.'
You could consider Slowly Changing Dimension as an
enlargement of your natural key: natural key of the
Employee was Employee Code 'E1' but for you it becomes
Employee Code Business Unit - 'E1' 'BU1' or 'E1' 'BU2.' But
the difference with the natural key enlargement process is
that you might not have all part of your new key within
your fact table so you might not be able to do the join on
the new enlarge key -> so you need another id.
| Is This Answer Correct ? | 3 Yes | 1 No |
Post New Answer View All Answers
Hello, Can you please send the admin and advanced mapping design sample questions to ns_sharmin@yahoo.com?
What is dimensional table? Explain the different dimensions.
How to create the source and target database connections in server manager?
What is dimensional table?
Name at least 5 different types of transformations used in mapping design and state the use of each.?
Hi all , I am planning for informatica S - PowerCenter 8 Mapping Design certification. I have rewuired the dumps for the same. if anyone of you having the same pl. share it with me. This will be of great help. My contact is : sagardev7@gmail.com TIA , Sagar
How do you load first and last records into target table? How many ways are there to do it? Explain through mapping flows.
1. When u r checking out what ll happens for version no? a. Increase b. decrease c.reset to 0 d. reset to 1 e. no change 2. Salary of all employees needed to add with the commision. What transfrmation to be used? a. SQ and Expression b. SQ c. Update Strategy d. Expression 3. Which of the task is used to run a session based on success of the other session? a. Decision b. Event wait c. Email d. Command e. None 4. Types of sources in Informatica? a. Homogenous n Heterogenous b. None c. Cobol n XML d. Flat files e. Flat files and Homogenous n Heterogenous 5. Servers are available in informatica? a. Informatica Server and Workflow server b. Informatica Server and Informatica Repository Server c. Informatica Server d. Workflow server e. Informatica Repository Server 6. While using Pmcmd in cmd line mode, each command must include the connection info of which of the following? a. workflow manager b. Power Center server c. Workflow monitor d. Repository manager e. Designer 7. Workflow montior displays workflows that have run a. once b. twice c. never d.four times e. thrice 8. Mode for handling sessions n workflows? a. server mode b. Wait mode c. Command line mode d. User mode e. Interactive mode 9. Connection details configured in? a. Mapping designer b. Workflow manager c. Workflow monitor d. Repository manager e. Worklet designer Thanks in Advance
How do you remove duplicate records in informatica? And how many ways are there to do it?
EXL informatica Questions
draw informatica architecture 8.6 ?
I have two different source structure tables, but I want to load into single target table? How do I go about it? Explain in detail through mapping flow.
can anybody send me some real time screenshots of mapping in informatica powercenter. i will be vary thankful to him. my e-mail id :- prakashkumar.kumhar@gmail.com
Tell me about your experience in informatica? what is best mark you can give yourself? How to answer this question?
Explain in detail about scd type 1 through mapping.
