CPU time = 0 ms, elapsed time = 1 ms.
SQL Server Execution Times:
CPU time = 0 ms, elapsed time = 1 ms.
DBCC execution completed. If DBCC printed error messages, contact your system administrator.
SQL Server Execution Times:
CPU time = 109 ms, elapsed time = 102 ms.
DBCC execution completed. If DBCC printed error messages, contact your system administrator.
SQL Server Execution Times:
CPU time = 0 ms, elapsed time = 1 ms.
SQL Server Execution Times:
CPU time = 0 ms, elapsed time = 1 ms.
SQL Server Execution Times:
CPU time = 0 ms, elapsed time = 1 ms.
SQL Server Execution Times:
CPU time = 0 ms, elapsed time = 1 ms.
SQL Server Execution Times:
CPU time = 0 ms, elapsed time = 1 ms.
(0 row(s) affected)
Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'free_room'. Scan count 2, logical reads 16, physical reads 1, read-ahead reads 48, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'free_room_use'. Scan count 1, logical reads 8, physical reads 5, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
(20 row(s) affected)
(1 row(s) affected)
SQL Server Execution Times:
CPU time = 0 ms, elapsed time = 27 ms.
SQL Server parse and compile time:
CPU time = 0 ms, elapsed time = 1 ms.
SQL Server Execution Times:
CPU time = 0 ms, elapsed time = 1 ms.
总结:在关联表的关联键上创建合适的索引会影响到SQL优化器对执行计划的选择。数据量的大小以及数据分布情况都会影响执行计划，所以对于SQL优化来说，不能一味套用概念，要实实在在的看到效果才算优化成功。
