What is Data Warehouse ?
Many companies already use Data Warehouse to manage their company data because Data warehouse can make their business process become easier to provide report to the management, because can support the company decision making process in an efficient way.
Definition of Data Warehouse
Data warehouse is a database that react with each other that can be used to query and analyst, is the orientation of the subject, integrated, time-variant, unchanged used to assist decision makers. Data warehouse is a method in the design of the database, which support the DSS (Decission Support System) and EIS (Executive Information System). Physically data warehouse is a database, but the data warehouse and database design is very different. In traditional database design using normalization, whereas the normalized data warehouse is not the best way.
Data Warehousing Tools and technologies – ETL Processes
Data warehouse has using ETL process to provide information to management by using this scheme :
To display the data, Data Warehouse extract data from transactional data and transform into the format which suitable with Enterprise, and load the data based on user requirement, that can be divided into several Data Marts.
The terms relating with data warehose
- Data Mart
Is a part of the data warehouse that supports the creation of report and analysis on a unit, section or the operation of a company. Data mart is created because people want to be easy to access the data that they use more often.
- On-Line Analytical Processing (OLAP)
Is a database processing that uses fact and dimension tables to display various kinds of reports, analyzes, queries of large-sized data.
- On-Line Transaction Processing (OLTP)
Is a processing that stores data on operational activities of daily transactions.
- Dimension Table
Table containing summaries categories with detailed data that can be reported. Such as profit on the fact table can be reported as the time dimension (in the form of monthly, and annual perkwartal).
- Fact Table
A table which generally contain only numbers and the history data in which the key (the key) that is produced is very unique, because it consists of the key foreign key (foreign key) which is the primary key (primary key) of some dimension tables are related.
A system that provides information to the user that explains how this system can analyze the situation and support a good decision.