外文翻译----高级数据库应用(编辑修改稿)

外文翻译----高级数据库应用(编辑修改稿)内容摘要：

In addition to words, handwritten data can include sketches, diagrams and so on. In the DreamHome case study, we may find the following requirements for handling multimedia. ■ Image data A client may query an image data base of properties for rent. Some queries may simply use a textual description to identify images of desirable properties. In other cases it may 4 be useful for the client to query using graphical images of features that may be found in desirable properties (such as bay windows, internal cornicing, or roof gardens). ■ Video data A client may query a video database of properties for rent. Some queries may simply use a textual description to identify the video images of desirable properties. In other cases it may be useful for the client to query using video features of the desired properties (such as views of the sea or surrounding hills). ■ Audio data A client may query an audio database that describes the features of properties for rent. Some queries may simply use a textual description to identify the desired property. In other cases it may be useful for the client to use audio features of the desired properties (such as the noise level from nearby traffic). ■ Handwritten data A member of staff may create notes while carrying out inspections of properties for rent. At a later data, he or she may wish to query such data to find all notes made about a flat in Novar Drive with dry rot. Digital publishing The publishing industry is likely to undergo profound changes in business practices over the next decade. It is being possible to store books, journals, papers, and articles electronically and deliver them over highspeed works to consumers. As with office information systems, digital publishing is being extended to handle multimedia documents consisting of text, audio, image, and video data and animation. In some cases, the amount of information available to be put online is enormous, in the order of petabytes (1015 bytes), which would make them the largest databases that a DBMA has ever had to manage. Geographic information systems (GIS) A GIS database stores various types of spatial and temporal information, such as that used in land management and underwater exploration. Much of the data in these systems is derived from survey and satellite photographs, and tends to be very large. Searches may involve identifying features based, for example, on shape, color, or texture, using advanced patternrecognition techniques. For example, EOS (Earth Observing System) is a collection of satellites launched by NASA in the 1990s to gather information that will support sci8entists concerned with longterm trends regarding the earth’s atmosphere, oceans, and land. It is anticipated that these satellites will return over onethird of a petabyte of information per year. This data will be integrated with other data 信息与计算科学毕业设计 5 sources and will be stored in EOSDIS (EOS Data and Information System). EOSDIS will supply the information needs of both scientists and nonscientists. For example, schoolchildren will be able to access EOSDIS to see a simulation of world weather patterns. The immense size of this database and the need to support thousands of users with very heavy volumes of information requests will provide many challenges for DBMSs. Interactive and dynamic Web sites ■ Consider a Web site that has an online catalog for selling clothes. The Web site maintains a set of prefe。