Difference in the implementation of lookup and join
stages,in joining two tables?
- 7 Answers
- 14363 Views
- TCS, I also Faced
- E-Mail Answers
Answer Posted / zulfi123786
Hi This is Zulfi
Basically Join is used when you have large amount of data
about in millions and it performs inner join,left
outer,right outer and full outer joins
The join stage requires the incomming data to be hash
partitioned and sorted on the joining keys
The look up is used when the reference records are fewer in
number about less than one lakh and it doesnot require the
incomming source data to be sorted, instead the refrence
link should be in Entire partition mode.
In look up there are two types
Normal and Sparse
Sparse is available only when the reference is a database.
usually Normal has to be used unless when the refrence to
source rows ratio is 100:1
| Is This Answer Correct ? | 8 Yes | 0 No |
Post New Answer View All Answers
What a datastage macro?
How do y read Sequential file from job control?
explain about citrix scheduling tool in datastage
Describe routines in datastage? Enlist various types of routines.
What is the Environment Variable need to Set to TRIM in Project Level?(In transfermer, we TRIM function but I need to impliment this project level using Environment variable)
Can you filter data in hashed file?
file having these input and we have to get 3 output using same job Input 1 1 1 2 3 4 4 4 o/p1 o/p2 o/p3 1 1 2 2 1 3 3 1 4 4 4
Can you explain engine tier in information server?
What is the method of removing duplicates, without the remove duplicate stage?
Differentiate between operational datastage (ods) and data warehouse?
Difference between sequential file and data set?
What is "fatal error/rdbms code 3996" error?
Define Routines and their types?
8000 jobs r there i given commit, suddenly job will abort? what happens? 2)diff b/t transformer stage & filter stage? 3)how to load the data in the source?
How to implement complex jobs in data stage?
