每个相匹配的命中结果都以排列好的次序返回，第一个结果具有最高的相关性，并按照它们的得分存储。
Each matching hit is returned in ranked order with the first result having the highest relevancy, stored as the score.
因为NPSI是一个单序列列表，很容易看到DB 2如何来回切换，从表到索引、索引到表，然后以ZIPCODE次序返回行，而不需要排序。
Because the NPSI is a single ordered list, it is easy to see how DB2 could just toggle back and forth, index to table, index to table, and return rows in ZIPCODE order without sorting.
当应用程序发出磁盘请求的速率快于磁盘返回数据的速率时，操作系统会让磁盘请求排队，还可能调整请求的次序以降低寻道时间。
The operating system queues disk requests when the applications issue them faster than the disks can return the data, optionally reordering them to minimize seeking.
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