数据库管理系统概述英文版课件：17 Data Warehouse

1、COMP231Data WarehousePrepared by Raymond WongPresented by Raymond WongData WarehouseAlso called Online Analytical Processing (OLAP)Many corporations use data warehouses for their analysisData WarehouseDatabasesUsersDatabasesUsersData WarehouseNeed to wait for a long time (e.g., 1 day to 1 week)Pre-c

2、omputed resultsQueryAdvantagesFast Query ResponseData WarehouseParts are bought from suppliers and then sold to customers at a sale price SPpartsuppliercustomerSPp1s1c14p3s1c23p2s3c17Table TData WarehouseParts are bought from suppliers and then sold to customers at a sale price SPpartsuppliercustome

3、rSPp1s1c14p3s1c23p2s3c17Table Tpartp1p2p3p4p5suppliers1s2s3s4customerc1c2c3c443Data cubeData WarehouseParts are bought from suppliers and then sold to customers at a sale price SPe.g., select part, customer, SUM(SP)from table Tgroup by part, customerpartcustomerSUM(SP)p1c14p3c23p2c17e.g., select cus

4、tomer, SUM(SP)from table Tgroup by customercustomerSUM(SP)c111c23pc 3c 2partsuppliercustomerSPp1s1c14p3s1c23p2s3c17Table TAVG(SP), MAX(SP), MIN(SP), Data Warehousepsc 6Mpc 4Mps 0.8Msc 2Mp 0.2Ms 0.01Mc 0.1Mnone 1Parts are bought from suppliers and then sold to customers at a sale price SPpartsupplier

5、customerSPp1s1c14p3s1c23p2s3c17Table TData WarehouseParts are bought from suppliers and then sold to customers at a sale price SPPartp1p2Electronic Devicep3FruitObjectpartsuppliercustomerSPp1s1c14p3s1c23p2s3c17Table TDigital CameraAppleCell Phonee.g., We want to find the sum of sale prices of each item in level itemItemCategoryTope.g., We want