1. what is the definition of normalized and denormali...

Normalization is the process of removing redundancies.

Denormalization is the process of allowing redundancies.

OLTP  uses the Normalization process and

the OLAP/DW uses uses the denormalised process to capture greater level of detailed data(each and every tranaction)

Thanks

venkat

Normalized View-> Process of eliminating the redundencies.

Denormalized View-> process the data where duplication takes place. Which means it is not stop the replication.

I would like to add one more pt. here, as OLTP is in Normalized form, more no. of tables are scanned or referred for a single query, as through primary key and foreign key data needs to be fetched from its respective Master tables. Whereas in OLAP, as the data is in De-normailzed form, for a query the no. of tables queried are less.

For eq.:- If we have a banking appln., in OLTP env., we will have a separate table for customer personal details , Address details, its transaction details etc..Whereas in OLAP env. these all details can be stored in one sinlge table thus decreasing the scanning of multiple tables for a single record of a customer details.