TOP N 和SET ROWCOUNT N 哪个更快
懒得翻译了，大意：
在有合适的索引的时候，Top n和set rowcount n是一样快的。但是对于一个无序堆来说，top n更快。
原理自己看英文去。
Q. Is using the TOP N clause faster than using SET ROWCOUNT N to return a specific number of rows from a query?
A. With proper indexes, the TOP N clause and SET ROWCOUNT N statement are equally fast, but with unsorted input from a heap, TOP N is faster. With unsorted input, the TOP N operator uses a small internal sorted temporary table in which it replaces only the last row. If the input is nearly sorted, the TOP N engine must delete or insert th...[ 查看全文 ]
2016-01-29
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