tailieunhanh - data warehousing fundamentals a comprehensive guide for it professionals phần 5

LÀM THẾ NÀO ĐỂ CUNG CẤP siêu dữ liệu kho dữ liệu của bạn đang được thiết kế và xây dựng, siêu dữ liệu cần được thu thập và ghi lại. Như bạn đã biết, siêu dữ liệu mô tả kho dữ liệu của bạn từ các điểm khác nhau của xem. Bạn nhìn vào kho dữ liệu thông qua các siêu dữ liệu để tìm các nguồn dữ liệu, | HOW TO PROVIDE METADATA 193 HOW TO PROVIDE METADATA As your data warehouse is being designed and built metadata needs to be collected and recorded. As you know metadata describes your data warehouse from various points of view. You look into the data warehouse through the metadata to find the data sources to understand the data extractions and transformations to determine how to navigate through the contents and to retrieve information. Most of the data warehouse processes are performed with the aid of software tools. The same metadata or true copies of the relevant subsets must be available to every tool. In a recent study conducted by the Data Warehousing Institute 86 of the respondents fully recognized the significance of having a metadata management strategy. However only 9 had implemented a metadata solution. Another 16 had a plan and had begun to work on the implementation. If most of the companies with data warehouses realize the enormous significance of metadata management why are only a small percentage doing anything about it Metadata management presents great challenges. The challenges are not in the capturing of metadata through the use of the tools during data warehouse processes but lie in the integration of the metadata from the various tools that create and maintain their own metadata. We will explore the challenges. How can you find options to overcome the challenges and establish effective metadata management in your data warehouse environment What is happening in the industry While standards are being worked out in industry coalitions are there interim options for you First let us establish the basic requirements for good metadata management. What are the requirements Next we will consider the sources for metadata before we examine the challenges. Metadata Requirements Very simply put metadata must serve as a roadmap to the data warehouse for your users. It must also support IT in the development and administration of the data warehouse. Let us .