which is better perfomancewise lookup or joiner and why?can anyone give example?
- 6 Answers
- 10117 Views
- TCS, I also Faced
- E-Mail Answers
Answer Posted / pawan
R u looking for flat or database file?
Generally sorted joiner more effective on flat files than lookup, because sorted joiner uses merge join and cache less rows. Lookup caches always whole file. If the file is not sorted, it can be comparable. Lookups into DB table can be effective if the DB can return sorted data fast and the amount of data is small, because lookup can create whole cache in memory. If DB responses slowly or big amt of data r processed, lookup cache initialization can be really slow.
Then it can be better use sorted joiner, which throws data to output as reads them on input.
| Is This Answer Correct ? | 0 Yes | 2 No |
Post New Answer View All Answers
I have three same source structure tables. But, I want to load into single target table. How do I do this? Explain in detail through mapping flow.
What is dimensional table? Explain the different dimensions.
How many ways a relational source definition can be updated and what are they?
What are the tuning techniques you applied during your last project
if i hv 6 table as source table but can i make 12 as a dim table and 6 as fact table belongs to that src table.
Explain the mapping variable usage example in informatica
What is confirmed fact in dataware housing?
What is workflow? What are the components of workflow manager?
What are the advantages of using informatica as an etl tool over teradata?
Mention few advantages of router transformation over filter transformation.
Where are the source flat files kept before running the session?
How can we handle two sessions in informatica?
Differentiate between router and filter transformation?
Which transformation should we use to normalise the COBOL and relational sources?
What is meant by active and passive transformation?
