Interpreted Transact-SQL stored procedures are compiled at first execution, in contrast to natively compiled stored procedures,
which are compiled at create time. When interpreted stored procedures are compiled at invocation, the values of the parameters
supplied for this invocation are used by the optimizer when generating the execution plan.This use of parameters during
compilation is called parameter sniffing.
Parameter sniffing is not used for compiling natively compiled stored procedures. All parameters to the stored procedure are
considered to have UNKNOWN values.Like interpreted stored procedures, natively compiled stored procedures also support
the OPTIMIZE FOR hint.
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Natively Compiled Stored Procedures在创建时编译，所有参数都视为UNKNOWN值，因此很有可能会生成比较中庸的执行计划。可视情况考虑
使用OPTIMIZE FOR hint来优化。
本文链接:http://www.cnblogs.com/ajiangg/p/6438556.html
参考链接:
https://msdn.microsoft.com/en-us/library/dn205319.aspx
关于Natively Compiled Stored Procedures的优化
原文：http://www.cnblogs.com/ajiangg/p/6438556.html