Difference in the implementation of lookup and join
stages,in joining two tables?
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
Define orabulk and bcp stages?
What are stage variables?
how to export or import the jobs in .ISX file
What are the difference types of stages?
how to implement scd2 in datastage 7.5 with lookup stage
Is it possible to implement parallelism in Mainframe Jobs ? If Yes how ? If no why ?
Can you filter data in hashed file?
What is ds designer?
What are the primary usages of datastage tool?
How the ipc stage work?
Differentiate between operational datastage (ods) and data warehouse?
What are the main features of datastage?
Why we use surrogate key?
how to get sum of sal based on dept_no and then sum of all sal irrespective of dept_no in same sql. output:- 10, 200(sum of sal for dept_no 10), 5000(sum of all sal)
How many Key we can define in remove duplicate stage?