Connected vs. Unconnected Lookups

CONNECTED LOOKUP	UNCONNECTED LOOKUP
Part of the mapping data flow	Separate from the mapping data flow
Returns multiple values (by linking output ports to another transformation)	Returns one value (by checking the Return (R) port option for the output port that provides the return value)
Executed for every record passing through the transformation	Only executed when the lookup function is called
More visible, shows where the lookup values are used	Less visible, as the lookup is called from an expression within another transformation
Default values are used	Default values are ignored

                                               

Frequently Interview ask questions for Informatica and Dataware house

1	Difference between unique key and primary key
2	Types of dimensions
3	Types of constraints
4	explain star schema
5	Delete duplicates
6	to pick the 3rd max sal from employees
7	What is target load plan/do we implent target load plan on different mappings
8	Difference between mapping parameter and variable
9	Challenges faced in your project and how did you overcome through it
10	why are resuable sessions used. how to use them
11	SCDtypes
12	structure of your project
13	Look up transformation..is look active or passive
14	Update stategy
15	aggregator
16	how to improve the perfomance of aggregator
17	Expression transformation/
18	joiner
19	joins in informatica
20	what is a unique constraint. how is it created
21	what is implit constraint.
22	what is composite constraint
23	what is partioning
24	how to abort/start wok flow throug unix
25	how did you use unix in your project
26	what is grep  command
27	scheduler used in your project
28	what is fact table
29	how are dimensions and fact related
30	explain facts and dimension with an example
31	explain sdlc process