作　　者： ;

机构地区： 黑龙江科技学院计算机与信息工程学院

出　　处： 《黑龙江科技学院学报》 2004年第3期192-195,共4页

摘　　要： 介绍在DML语言中,基于语句级的提示的分类,阐述分类选项、功能,结合SQLServerpubs样本数据库中相关基表测试大量数据,通过select语句分析提示在影响优化器创建执行计划中的作用,得出结论,即有的查询可以被优化,有的则不能。使用提示时,建议测试提示应用前后性能的变化,如成本值是否降低,效率是否提高等,根据优化结果确认是否应用提示。 This paper discusses the classes of hint based on sentences in DML, introduces all kinds of options and functions, and tests a great lot of data using pubs database in the SQL Server. The paper analyzes effect on creating execute plan of optimization by using SELECT sentence and offers the conclusion that some queries may be optimized and some not. It is suggested that the test of hint involves testing changes of performance before and after the use of hint, such as possibility of reducing the values of cost and increasing efficiency and confirming application of hint in terms of conclusion of optimization.

关 键 词： 提示 优化 执行计划

领　　域： [自动化与计算机技术] [自动化与计算机技术]