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 Informatica  |  Question 42 of 630    Print  
Why use the lookup transformation ?
To perform the following tasks.
Get a related value. For example, if your source table includes employee ID, but you want to include the employee name in your target table to make your summary data easier to read.
Perform a calculation. Many normalized tables include values used in a calculation, such as gross sales per invoice or sales tax, but not the calculated value (such as net sales).
Update slowly changing dimension tables. You can use a Lookup transformation to determine whether records already exist in the target.




  
Total Answers and Comments: 5 Last Update: May 13, 2008   
  
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August 21, 2006 22:26:47   #1  
samba        

RE: Why use the lookup transformation ?

Lookup table is nothing but the lookup on a table,view,synonym and falt file.

by using lookup we can get a related value with join conditon and performs caluclations

two types of lookups are there

1)connected

2)Unconnected

connected lookup is with in pipeline only but unconnected lookup is not connected to pipeline

unconneceted lookup returns single column value only

let me know if you want to know any additions information

cheers

samba


 
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January 05, 2007 10:30:56   #2  
       

RE: Why use the lookup transformation ?
hey,  with regard to look up , is there a dynamic look up and static look up ? if so how do you set it. and is there a combinationation of dynamic connected lookups..and static unconnected look ups.?
 
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January 09, 2007 02:22:57   #3  
       

RE: Why use the lookup transformation ?
look up has two types ,Connected and Unconnected..Usually we use look-up so as to get the related Value from a table ..it has Input port ,Output Port ,Lookup Port and Return Port..where Lookup Port looks up the corresponding column for the value and resturn port returns the value..usually we use when there are no columns in common
 
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March 22, 2007 00:37:22   #4  
binoop        

RE: Why use the lookup transformation ?
For maintaining the slowly changing diamensions
 
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May 08, 2008 01:25:14   #5  
vivek1708 Member Since: May 2008   Contribution: 18    

RE:

Hi

The ans to ur question is Yes
There are 2 types of lookups: Dynamic and Normal (which you have termed as Static).

To configure, just double click on the lookup transformation and go to properties tab
There'll be an option - dynamic lookup cache. select that...

If u dont select this option, then the lookup is merely a normal lookup.

Please let me know if there are any questions.

Thanks.


 
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