Difference in the implementation of lookup and join
stages,in joining two tables?

Answer Posted / krishna

Generally we are using lookup for comparision purpose,
based on the reference table size we r using join or lookup.

If the reference table size is less than the main table
then use lookup stage other wise use join stage.
In lookup we have two types:
Normal lookup - reference lookup is less no of rows
compared to main table
sparse lookup - reference lookup is more no of rows
compared to main table.
But the peformance wise use join if the reference table has
more data.

Regards,
Krishna

Is This Answer Correct ?    8 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is the difference between the local container and shared container?

654


Lookup constraints

844


What is the difference between datastage and informatica?

616


What is apt_config in datastage?

708


What is the difference between validated and compiled in the datastage?

707






Hi All , in PX Job I have passed 4 Parameters and when i run the same job in sequence i dont want to use those parameters , is this possible if yes then how

1124


How a routine is called in datastage job?

611


Is the value of staging variable stored temporarily or permanently?

582


Define ds designer?

770


What are the types of hashed files in data stage

650


Differentiate between datastage and informatica?

729


Does datastage support slowly changing dimensions ?

663


How one source columns or rows to be loaded in to two different tables?

668


Hi guys, Please design a job for dis requirement with derivation(solution). my source table like dis. emp_no qualification 1 a 1 c 2 a 3 c 3 b To loaded to target like dis emp_no qualification 1 b 2 b 2 c 3 a my requirement is every employer have three qualifications i.e a,b and c. what qualification missed in source table that will be move to target systems. Hope u got it the requirement. Right Thanks.

2440


How do you schedule or monitoring the job?

675