Was asked if knowing ODS today. Wikied, and got:
An operational data store (or "ODS") is a database designed to integrate data from multiple sources to make analysis and reporting easier. Because the data originates from multiple sources, the integration often involves cleaning, resolving redundancy and checking against business rules for integrity. An ODS is usually designed to contain low level or atomic (indivisible) data (such as transactions and prices) with limited history that is captured "real time" or "near real time" as opposed to the much greater volumes of data stored in the Data warehouse generally on a less frequent basis.
[@more@]According to Bill Inmon, the originator of the concept, an ODS is "a subject-oriented, integrated, volatile, current-valued, detailed-only collection of data in support of an organization's need for up-to-the-second, operational, integrated, collective information."ODS differ from Inmon's definition of Enterprise data warehouse by having a limited history, and more frequent update than an EDW. In practice ODS tend to be more reflective of source structures in order to speed implementations and provide a truer representation of production data.
数据仓库之父W.H.Inmon于1995年提出了操作型数据存储（Operational Data Store）的概念：ODS为企业提供即时的，操作型的，集成的数据集合，具有面向主题性，集成性，动态性，即时性，明细性等特点。由该定义可以看出，Inmon提出ODS概念的本意，是要弥补数据仓库在支持即时的、明细的、轻量集成的操作数据时的不足。ODS作为数据库到数据仓库的一种过渡形式，在企业数据架构中形成了DB-ODS-DW的三层体系结构。
随着大型企业建设数据仓库的风险被逐渐暴露出来，许多企业都开始关注ODS。行业领头的企业集成软件商SAP、Oracle Financials、IBM等都已经接受并采用三层架构来构架企业的数据架构。随着技术的发展和企业数据架构的演变，ODS也逐渐成为一种独立的数据集成解决方案。