Lists topics on creating, modifying, running, and copying queries as well as basic topics on sorting, ordering, and printing query results.
列出关于创建、修改、运行和复制查询的主题以及关于将查询结果排序和打印的基本主题。
2
Sorting is required when no index satisfies the requested ordering of fetched rows, or the optimizer determines that a sort is less expensive than an index scan.
如果没有索引满足所取的行的要求顺序，或者优化器断定排序的代价低于索引扫描，那么就需要进行排序。
3
Sorting and classifying are two basic kinds of knowledge and mining ordering rules is a novel thought. The algorithms for ordering rules is discussed deeply and improved in this paper.