Rishi

• Dec 7th, 2005

 

Its not a easy question to say which is better out of connected, unconnected lookups. Its depends upon our experience and upon the requirment.

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 o/p of one lookup is going as i/p of another lookup this unconnected lookups are favourable.

sithusithu

 Profile Answers by sithusithu 

• Jan 19th, 2006

 

If you are having defined source you can use connected, source is not well defined or from different database you can go for unconnected

We are using like that only

 

Asking question is very easy, but?

 

Cheers

Sithu

gazulas

 Profile Answers by gazulas Questions by gazulas

• Jan 29th, 2006

 

i think the better one is connected look up. beacaz we can use dynamic cache with it ,, also connected loop up can send multiple columns in a single row, where as unconnected is concerned it has a single return port.(in case of  etl informatica is concerned)

prasadns26

 Profile Answers by prasadns26 

• Jul 18th, 2006

 

hi,

my friend kishore,

it all depends on the requirments. dynamic cache is usually not preffered as a performance issue.it reduces. only when u want to track the changes to the target table records in that perticular run, u will be using the dynamic cache.

when u want to use the same lookup table many times in the same mapping, then obviously u go for a unconnected lookup rather than creating same connected lookup many times.

as i said earlier each has its own advan and disadvan and it depends on the requirment.

Vani_AT

 Profile Answers by Vani_AT 

• Apr 3rd, 2008

 

Connected and Unconnected lookups have their own pros and cons.
Unconnected lookup is designed for a specific purpose.
The task that an unconnected lookup does can be done by a connected lookup also. They why is there a concept of unconnected lookup?

If any objective that a connected lookup is achieving can be achieved using an unconnected lookup, we must go for an unconnected lookup.
For eg. if we are returning only a single column from a table with small no. of rows, then go for an unconnected lookup. The same unconnected lookup can be used many time.
It all depends on the requirement.
I prefer using unconnected lookup wherever possible in big complex mappings because my design looks simpler.

Racp238

 Profile Answers by Racp238 

• Apr 3rd, 2008

 

Why not just use an inline select statement in your sql qualifier to eliminat the overhead of a lookup transformation all together?