Les12 Transportation Loading Warehouse Data 数据仓库英文oracle99版 教学课件.pptVIP

Transportation: Loading Warehouse Data Overview Project Management (Methodology, Maintaining Metadata) DefiningDW Concepts Terminology Planningfor a SuccessfulWarehouse AnalyzingUser QueryNeeds Choosing aComputingArchitecture Modeling the DataWarehouse PlanningWarehouseStorage ETT(Building theWarehouse) Meeting aBusinessNeed SupportingEnd UserAccess Managing the Data Warehouse Objectives After completing this lesson, you should be able to do the following: Explain key concepts in transporting data into the warehouse Outline how to build the transportation process for first time load Identify transportation techniques Identify the tasks that take place after data is loaded Explain the issues involved in designing the transportation, loading, and scheduling processes Transporting Data into the Warehouse Loading moves the data into the warehouse Loading can be time-consuming: Consider the load window Schedule the task; automate all processes Initial load moves large volumes Subsequent refresh moves smaller volumes Business determines the cycle Extract Transform OperationalSystem Transport(load) DataStagingArea Warehouse Extract Processing Environment After each time interval, build a new database Run queries T1 T2 T3 Operational databases Warehouse Processing Environment Build a new database After each time interval, add changes to database Archive or purge oldest data Run queries T1 T2 T3 Operational databases First-Time Load Single event that populates the database with historical data Involves large volume of data Employs distinct ETT tasks Involves large amounts of processing after load T1 T2 T3 Operational databases Refresh Performed according to a business cycle Simpler task Less data to load than first-time load Less-complex ETT Smaller amounts of post load processing T1 T2 T3 Operational databases Building the Transportation Process Specification Techniques and tools File transfer method