Learn in the textbookBI, Data Warehouse, and Mining
DefinitionA data warehouse (データウェアハウス) is a database that integrates data scattered across departmental business systems and accumulates it over time for analysis.
ExplanationIt is abbreviated DWH, and a warehouse is simply a storehouse. Gathering records from separate systems in one place makes it possible to compare company-wide activity over long periods. An operational database that handles daily orders prioritizes keeping its data current, whereas a data warehouse keeps past records for analysis.
AnalogyThink of a head-office archive where copies of every branch's ledgers are filed by year. Older ledgers are kept too, so you can compare across years.