What are slowly changing dimensions?

Answers were Sorted based on User's Feedback



What are slowly changing dimensions?..

Answer / sri ram

Slowly Changing Dimensions:(SCD)
Over period of time, the value /data associated with
dimensions may change. To track the changes we record the
changes as per the requirement.
There are three types of SCD
SCD 1:No history is maintained. As and when data comes, the
data is entered.
SCD 2: History is maintained
SCD 3: Partial History is maintained.
We maintain history for some columns but not for all.
For example,I have 3 records in a dimension
I have made 1 insert and 1 update. Then if the requirement
is that dimension is to be maintained
In SCD 1 Then
Total number of records is 4 records(1 insert & 1 update)
In SCD 2 Then
Total number of records is 5 records(1 insert & 1 update)
In SCD 3 Then
Total number of records is 4 records(1 insert & 1 update)
NOTE:
History means the slight change in the data stored and
incoming data but it doesn't means years of data.

Is This Answer Correct ?    36 Yes 5 No

What are slowly changing dimensions?..

Answer / sandeep.t nizamabad

DIMENSIONS ARE CLASSIFIED INTO THREE TYPES
SCD TYPE-1 (MAINTAIN CURRENT DATA)
SCD TYPE-2 (MAINTAIN CURRENT DATA+FULL HISTORY OF CHANGES)
SCD TYPE-3 (MAINTAIN CURRENT DATA+ONE TIME HISTORY)

Is This Answer Correct ?    27 Yes 2 No

What are slowly changing dimensions?..

Answer / anitha

scds are three types.
type1:it stores the current data.

type2:it stores the full historical data.

type3:it stores the current and previous data in the target...

Is This Answer Correct ?    11 Yes 0 No

What are slowly changing dimensions?..

Answer / chaitanya

SCD, is a technique used to store the historical value of
dimension attributes.

The values of dimensional attributes change as time goes by.
When these attribute values change, you can overwrite the
old values with the new ones, or you can
preserve the old value.

There are two methods of preserving the old attribute
values: you can store the old values as rows, or you can
store them as columns

three types of SCD:
• SCD type 1 overwrites the old values of the attributes so
the old values are not kept.
Ex: In product dimension,we will use SCD type 1, meaning we
will overwrite the old attribute values.

SCD type 2 keeps the old values by creating a new row for
each change.
SCD type 3 keeps the old values by putting them in another
column

Is This Answer Correct ?    0 Yes 1 No

What are slowly changing dimensions?..

Answer / ande

there are three types SCD:
type-1: in this we can over write original recourd with new
record
type-2: we can create new record
type-3: we can create new attribute
regards,
ande

Is This Answer Correct ?    9 Yes 23 No

Post New Answer

More Informatica Interview Questions

Enlist the various types of transformations.

1 Answers  


explain about session partitions ?

1 Answers  


What is joiner cache?

2 Answers   TCS,


if i hv 6 table as source table but can i make 12 as a dim table and 6 as fact table belongs to that src table.

1 Answers   iGate,


what is mean by throghput? in informatica

3 Answers   Cap Gemini,


HOW CAN I SEND HALF OF THE RECORDS TO ONE TARGET AND REMAINING TO OTHER TARGET?

6 Answers  


Explain joiner transformation in informatica

1 Answers   Informatica,


which one is better either active or passive transformation in informatica

1 Answers  


CANNOT USE PARAMETER FILE! Hi all, I am trying to use parameter file for my workflow. This could help me to filter records where CITY = 'Portland' Following is what I have done: **in Designer - create new parameter : $$PARA_FIL, Parameter, String, IsExprVar=TRUE, Initial value = [empty] - Source Qualifier/ Properties/Source Filter: CUSTOMERS.CITY='$$PARA_FIL' **Create Parameter file: C:\Informatica\PowerCenter8.6.0 \server\infa_shared\BWParam\DynamicParamTest.txt $$PARA_FIL='Portland' **Configure workflow to use the parameter file: Edit Workflow/Properties/Parameter Filename: C:\Informatica\PowerCenter8.6.0 \server\infa_shared\BWParam\DynamicParamTest.txt I also configured directory of parameter file for session task. However, I just got this in the session log: [SQ_CUSTOMERS] SQL Query [SELECT CUSTOMERS.CUSTOMER_ID FROM CUSTOMERS WHERE CUSTOMERS.CITY='$$PARA_FIL'] No record has been loaded to target. It seems that the parameter file has not been read. I cannot understand the reason why. Could any of you kindly suggest me anything? Thanks

5 Answers   CSC,


what is the logic will you implement to load data into a fact table from n dimension tables?

4 Answers   TCS,


i have a table like empid ename year month sal 1 x 98 jan 500 1 x 98 feb 500 1 x 98 mar 500 1 x 99 jan 600 1 x 99 feb 600 2 y 98 jan 600 2 y 98 feb 600 2 y 98 mar 600 2 y 99 jan 700 2 y 99 jan 700 and so on i want to find out totsal for every emp on year wise plz help me

4 Answers   Magna Infotech,


Please let me know how to make Data masking in informatica..

1 Answers  


Categories