Online Transaction Processing (OLTP)

Operations/Transactions:

• INSERT
• DELETE
• UPDATE
• QUERY

DBMS:

• Concurrency control
• Recovery
• Security

Online Analytic Processing (OLAP)

• Data uploaded periodically
• Queries consist of aggregates (SUM, COUNT, MIN, etc) and are used for trends and icebergs

Data Cubes

A data warehouse is based on a multidimensional data model which views data in the form of a data cube.

Data Warehouse

A data warehouse is a subject-oriented, integrated, time-variant, and nonvolatile collection of data. Data warehousing is the process of constructing and using data warehouses.

Benefits of a separate data warehouse

• High performance for both systems
  • DBMS is best for OLTP, access methods, indexing, concurrency control and recovery
  • Warehouse is best for OLAP: complex OLAP queries, multidimensional view, consolidation
• supports historical data (no missing data)
• data consolidation
• data quality, different sources typically use inconsistent data representations, codes and formats which have to be reconciled