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Informatica INTERVIEW QUESTION & ANSWERS
|16.||What is difference between view and materialized view?|
|Views contains query whenever execute views it has read from base table.
A view which is physically stored in a database. Materialized views allow query performance to be enhanced by precalculating costly operations.
|17.||What is surrogate key?|
|A system generated artificial primary key that is not derived from any data in the database. It is similar to the object identifier in an object oriented system.|
|18.||What is a folder?|
|Folder contains repository objects such as sources, targets, mappings, transformation which are helps logically organize our data warehouse.|
|19.||What is pivot?|
|The pivot (or rotate) operation rotates the axes of a cube to provide an alternative presentation of the data.|
|20.||What is the difference between mapping and session?|
|Maping : It is a set of source and target definitions linked by transformation objects that define the rules for transformation.
Session : It is a set of instructions that describe how and when to move data from source to targets.