retech

• May 16th, 2006

 

it depends

Motilal

• Jun 30th, 2006

 

Yes Exactly Depends.

Definitely unconnected is better performance wise.

But its not wise to use 5 unconnected lookups. In this case better to use one connected with the required 5 ports as output port. If u need only one or two output port, you can use unconected for better performance.

ashok

• Jul 4th, 2006

 

  how can u say that unconnected is better performance then connected lookup.

  in connected lookup we are going to use only lookup table in unconnected we are going to add an expersion with lookup table then the performance in unconnected lookup is decreased due to another transformation than connected lookup

viram

• Mar 28th, 2007

 

It depends on the scenario u r using, if u want to lookup multiple times for the same condition in one mapping it is better to use unconnected lookup and in the situation like when u want multiple return values then u can only use connected lookup. In connected lookup, we can use  both static and dynamic cache but in case of unconnected lookup, we can use only static cache. 
from
vinod

SRIRAM N

• May 7th, 2007

 

it depends on the requirement.
If you want to retrieve more than one port values then use connected(dynamic/static cache).
If you want to retrieve one port value then use unconnected(static cache).

rishiverma2001

• Jul 26th, 2007

 

Unconnected lookup can also be used to return multiple values through one port. Override the lookup query to concatenate all the return columns from the lookup table and parse the value in the expression where lookup is being called.

siraj.khan

• Aug 3rd, 2007

 

Unconnected Lookup is always better..It takes less time as compared to that of Connected Lookup.Because Unconnected Transformation is Isolated within the mapping,we can call this lookup with the help of a Expression transformation.Where as connected loopup is connected in a single pipeline from source to target.

chandrarekha

• Oct 3rd, 2007

 

Unconnected is better by performance wise, bcoz unconnected look up does not invove in the mapping, we are calling from another transformation, so it mimimizes the lookup cache value
In connected, it is connected to the tranformations, so it keeps values in lookup cache.

superhero

 Profile Answers by superhero Questions by superhero

• Dec 4th, 2008

 

If you want to reuse the lookup out put in diffrent transformations you can go for un-connected lookup otherwise according to situations we can go for either connected / unconnected.

Baloo_nanduri

 Profile Answers by Baloo_nanduri 

• Jul 25th, 2010

 

Connected lookup lends best performance and also you can cache or uncache connected look up unconnected look up is used only when you have to use it as a function call both have its own benefits, using 5 connected lookup's is not a big deal until your mapping is tuned well.

Ganesh kumar

• Sep 4th, 2013

 

yes, I Agree your answer,.....