Data Warehouse-
we discuss here what is data warehouse in brief, In industry lots of data available from day to day transaction history. the whole data saved in operational database, the operational database include text data, video data, audio data, 2D, 3D , presentation, excel data etc. that all data saved in operational database but fallow unstructured format. in that data not saved clean format, all data saved with noisy and incorrect data.
In DW collect a useful data from operational database system. DW is important factor in big industry for saving data with good manner, In that include data with useful manner and that data is used for DSS(decision support system). the all data saved in DW is a variant data, non-volatile and subject oriented data. In DW saved all historical data from that industry.. the all historical data merged in to single DW.
In data warehouse consist informational data. the data extracted from operational database bu before extract that data was cleaned and summarized. in fallowing figure shows the main three methods that are used for getting data from DW.
Data extract from DW with –
- Query Tool
- OLAP (Online Analytical Processing) Tool
- Data Mining Tool
Data Warehouse Features-
1. Subject Oriented-
Data warehouse is basically subject oriented means in DW saved a data with clean manner. the all data saved in Dw indicating a historical condition about that organization.ex- sales information, customer information
2. Integrated-
In DW data coming from various data sources like operational databases, relation database that all data integrated enhancing for analysis of data.
3. Time Variant-
In DW historical data saved with a particular time period. that all data used in future with data mining time series analysis method for predict a future outcomes.
4. Non-volatile-
Data warehouse extract data from different data sources but if new data added in DW the previous data can not be deleted from DW so it fallows non volatile property.