Interested to Buy Any Domain ? << Click Here >> for more details...
Please explain me the difference between 3 types of slowly
changing dimension in datawarehousing?
- 3 Answers
- 18726 Views
- TCS, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / rameshgoud
scd1-> with this process we can maintain only updated data,
for ex- if a record inserted in source then the same record
should be inserted in targer, if a record updated in the
source then same update should process in target, so here
we cant maintain the history
scd2->with this we can maintain current data and complete
historical data by adding the start_date and end_date of
the records in the target table. If a records get updated
in the source same record will insert in the target as new
record and the old record is updated with end date as
todays date. Like wise we there will no be any deletion of
records, so we can maintain the compelte history here.
scd3-> using this we can maintain current and recent
historical data only
for every source possible changing column we need two
target columns as NEW_COLUMN indicates current data and
OLD_COLUMN indicates recent historical data
when a new record getting loaded source data is always
loded in NEW_COLUMN in target
when a record is midified target NEW_COLUMN is updated in
target OLD_COLUMN and source data is updated in target
NEW_COLUMN.
| Is This Answer Correct ? | 17 Yes | 1 No |
scd1 ---->will contain only the updated data(ie it contains
the newly entered data + updates of historic data)it dose
not maintain historic data
scd2 ---->it contains the updated data and the historic data
(full history)
scd3 ----->it contains updated data and historic data
partially(means it may contain the records of the last
6months i think)
| Is This Answer Correct ? | 3 Yes | 9 No |
scd 1:It wont implement the new change.It always contains
the historic data alone.
scd 2:It will replace or overwrite the existing record.It
will not contain the historic data.But it has surrogate key.
scd 3:It contains both the old data and a new record with
the modified information and has additional columns like
"effective start date and end date" or "version no".
Please correct me if i am wrong
| Is This Answer Correct ? | 0 Yes | 20 No |
What are the important features of datastage?
Explain briefly scd type2 in datastage7.5x2(parallel)
how will u design file watch jobs?
create a job that splits the data in the Jobs.txt file into four output files. You will direct the data to the different output files using constraints. • Job name: JobLevels • Source file: Jobs.txt • Target file 1: LowLevelJobs.txt − min_lvl between 0 and 25 inclusive. − Same column types and headings as Jobs.txt. − Include column names in the first line of the output file. − Job description column should be preceded by the string “Job Title:” and embedded within square brackets. For example, if the job description is “Designer”, the derived value is: “Job Title: [Designer]”. • Target file 2: MidLevelJobs.txt − min_lvl between 26 and 100 inclusive. − Same format and derivations as Target file 1. • Target file 3: HighLevelJobs.txt − min_lvl between 101 and 500 inclusive. − Same format and derivations as Target file 1. • Rejects file: JobRejects.txt − min_lvl is out of range, i.e., below 0 or above 500. − This file has only two columns: job_id and reject_desc. − reject_desc is a variable-length text field, maximum length 100. It should contain a string of the form: “Level out of range: <min_lvl>”, where <min_lvl> is the value in the min_lvl field. My Question is how do you write the stage variable for reject rows.
how to run jon in unix back round process what is command use in runing a job?
1)what is the size of Fact table and dimension table? 2)how to find the size of Fact table and dimension table? 3)how to implement the surrogate key in transform stage? 4)write the configuration file path? 5)how many types of datasets explain? 6)diff b/w developed projects and migration projects? 7)how to delete the header and footer file of the sequencer file? 8)how can u call the parameters in DS in unix environment? 9) how much data ur getting daily ? 10)
for example You have One Table with 4 Columns (Mgr ID, Department ID, Salary, Employee ID). Can you find out the Average Salary and Number of Employee present per Department and Mgr
What is confirmed Dimension? what is Factless Fact? give one example? What are Additive, Semi-Additive Facts?
What is a merge?
Why we need datasets ratherthan sequential files?
What is the difference between orabulk and bcp stages?
i have a scenario with i/p as ID,salary with values 1,1000 2,2000 and 3,4000 i need an extra column in the o/p named amount with values 2000,4000 and NULL. how can i get it?
Teradata 
