Interested to Buy Any Domain ? << Click Here >> for more details...
when will we use unconnected & connected lookup? How it
will effect on the performance of mapping?
- 5 Answers
- 16431 Views
- Accenture, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / sweta kedia
A. Connected Lookup
Receives input values directly from the pipeline.
We can use a dynamic or static cache
Supports user-defined default values
Unconnected Lookup
Receives input values from the result of a :LKP expression
in another transformation.
We can use a static cache
Does not support user-defined default values
When you compared both basically connected lookup will
return more values and unconnected returns one value. conn
lookup is in the same pipeline of source and it will accept
dynamic caching. Unconn lookup don't have that faclity but
in some special cases we can use Unconnected. if output of
one lookup is going as input of another lookup this
unconnected lookups are favourable
Moreover if the mapping requires multiple lookup using same
lookup conditions then its better to use unconnected lookup
& call the lookup wherever required.This also prevents the
mapping from being complex.
| Is This Answer Correct ? | 3 Yes | 0 No |
Answer / v.ramakrishna
when it comes to the matter of performance optimization we
can understand the diff between conn lookup and unconn
lookup y bcoz in conncted lookup it will give more than one
output. when compared with the performance of unconn lookup
it is some what slower bcoz the execution times in conn
lookup is equal with no of records present in source . so
it will increase running time . where as in unconn lookup
it executes only for records which satisfy the given
condition so no need to call lookup for each and every
record unneccesarily. so it leads to performance
development in unconn lookup compared wth conn lookup.
| Is This Answer Correct ? | 3 Yes | 1 No |
Answer / nag
Connected Lookup
Receives input values directly from the pipeline.
We can use a dynamic or static cache
Supports user-defined default values
Unconnected Lookup
Receives input values from the result of a :LKP expression
in another transformation.
We can use a static cache
Does not support user-defined default values
When you compared both basically connected lookup will
return more values and unconnected returns one value. conn
lookup is in the same pipeline of source and it will accept
dynamic caching. Unconn lookup don't have that faclity but
in some special cases we can use Unconnected. if output of
one lookup is going as input of another lookup this
unconnected lookups are favourable
| Is This Answer Correct ? | 2 Yes | 1 No |
Answer / jeevan kumar medapati
if u want to perform look up on less values then we go for
connected lkp
if u want to perform look up from more than one table then
we go for un connected lkp
in ur source u have more date columns then we should go for
unconnected lkp.
| Is This Answer Correct ? | 1 Yes | 1 No |
how DTM buffer size and buffer block size are related
can you use flat file for lookup table?why?
write sql query following table quarter sales q1 1000 q1 2000 q1 3000 q1 4000 q2 5000 q2 6000 q2 7000 q2 8000 q3 1000 q3 2000 q3 3000 q3 4000 q4 5000 q4 6000 q4 7000 q4 8000 i want the output format like q1 q2 q3 q4 1000 5000 1000 5000 2000 6000 2000 6000 3000 7000 3000 7000 4000 8000 4000 8000
Hi I have two sources like A, B. My source A contain 10000 million records from that i need 20 attributes. My source B has also same 10000 million records from that i need only 1 attribute. By using Joiner i have to load into target? Is there any issue regarding this? if issue is there how to tune this mapping in best way?
How to write a procedure for a date which is in three different formats,and you want to load into datawarehouse in any single date formate
Explain target update override in informatica
have u done any performance tuning? how u ll do?
on a day i load 10 rows in my target and on nextday i get 10 more rows add to my target but out of 5 are update row how ican send them to target?how i can insert and update the records
What is the meaning of up gradation of repository?
What are the designer tools for creating tranformations?
Explain grouped cross tab?
Can any one give me a real time example for FACT TABLE & DIMENSIONAL TABLE?
Teradata 
