what is the main differences between Lookup, Join and Merge
stages?
- 9 Answers
- 144824 Views
- HCL, I also Faced
- E-Mail Answers
Answer Posted / kpk
all three stages are used to join database tables based on a
key column.
Lookupsate: input 1 reference any number (if oracle or DB2
only 1 reference link) one out put link and one reject link.
faster if the volume of data is less than the memory size.
if the siz is too huge then DS uses scrap files to store the
remaining datas and that hinders the performance.
Joinstage: can have any (but i think only 16 )tables can be
joined. does not use memory, look up is done on table level,
so would be better to use if the data volume is pretty
huge.dosent have any reject link. only one out put link.
Mergestage: can have any number of input link and update
link. need to have a key column. can have any number of
reject link. only one out put link.
| Is This Answer Correct ? | 25 Yes | 17 No |
Post New Answer View All Answers
What are stage variables?
Hi, what is use of Macros,functions and Routines..? At what situation you are used. If you know the answer please explain it. Thanks.
explain about completely flow of sequencers technicaly,without using example??explain about lookup,nullhandling?
How and where you used hash file?
Can you implement SCD2 using join, transformer and funnel stage?
How to read the length of word in unix?
State the difference between an operational datastage and a data warehouse?
What are the types of containers?
In work load management there are three options of Low priority, Medium priority and High Priority Jobs which can be used for resource management. why this feature is developed when there is already jobs prescheduled by scheduler or autosys. what will be the use of workload management then?
DB2 connector> transformer > sequential file Data will be exported into a csv format in a sequential file. This file will be send in a email using a sequence job. Problem here is, how to avoid sending a blank csv file? When I ran the job there are chances that it might return zero records but in the sequence job csv file is going blank. how can I avoid this? thanks
Can you explain players in datastage?
Which algorithm you used for your hashfile?
Can you filter data in hashed file?
What are the different plug-ins stages used in your projects?
Have you have ever worked in unix environment and why it is useful in datastage?
