▪︎OLAP stands for Online Analytical Processing Server.
▪︎It is based on the multidimensional data model.
▪︎It allows managers, and analysts to get an insight of the information through fast, consistent, and interactive access to information.
Types of OLAP Servers:
1)Relational OLAP (ROLAP):
▪︎ROLAP servers are placed between relational back-end server and client front-end tools.
▪︎To store and manage warehouse data, ROLAP uses relational or extended-relational DBMS.
2)Multidimensional OLAP (MOLAP):
▪︎MOLAP uses array-based multidimensional storage engines for multidimensional views of data.
▪︎With multidimensional data stores, the storage utilization may be low if the data set is sparse
3)Hybrid OLAP (HOLAP):
▪︎Hybrid OLAP is a combination of both ROLAP and MOLAP.
▪︎It offers higher scalability of ROLAP and faster computation of MOLAP.
▪︎HOLAP servers allows to store the large data volumes of detailed information.
4)Specialized SQL Servers
▪︎Specialized SQL servers provide advanced query language and query processing support for SQL queries
Operations:
1)Roll-up
2)Drill-down
3)Slice and dice
4)Pivot
▪︎OLAP systems are used by knowledge workers such as executives, managers and analysts.
▪︎It focuses on Information out.
▪︎It Provides summarized and multidimensional view of data.
