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
Difference between IBM DATA STAGE8.5 and DATA STAGE9.1 ?
What are system variables and sequencers in datastage
I have a few records just I want to store data in to targets cycling way how?
How the ipc stage work?
In Informatica,for the table I can find coreesponding dependent mappings.Likewise can I find the dependent jobs with all the information by using the table name
sed,awk,head
What are routines in datastage? Enlist various types of routines.
What is the difference between operational data stage (ods) and data warehouse?
What is job control?
What is the difference between account and directory options ?
What is the process of killing a job in datastage?
AGGREGATOR default datatype
What is the flow of loading data into fact & dimensional tables?
What is the difference between server job and parallel jobs?
Distinguish between informatica & datastage. Which one would you choose and why?