Recompile a Stored Procedure
This topic describes how to recompile a stored procedure in SQL Server by using Transact-SQL. There are three ways to do this: WITH RECOMPILE option in the procedure definition or when the procedure is called, the RECOMPILE query hint on individual statements, or by using the sp_recompile system stored procedure. This topic describes using the WITH RECOMPILE option when creating a procedure definition and executing an existing procedure. It also describes using the sp_recompile system stored procedure to recompile an existing procedure.
In This Topic
Before You Begin
When a procedure is compiled for the first time or recompiled, the procedure's query plan is optimized for the current state of the database and its objects. If a database undergoes significant changes to its data or structure, recompiling a procedure updates and optimizes the procedure's query plan for those changes. This can improve the procedure's processing performance.
There are times when procedure recompilation must be forced and other times when it occurs automatically. Automatic recompiling occurs whenever SQL Server is restarted. It also occurs if an underlying table referenced by the procedure has undergone physical design changes.
Another reason to force a procedure to recompile is to counteract the "parameter sniffing" behavior of procedure compilation. When SQL Server executes procedures, any parameter values that are used by the procedure when it compiles are included as part of generating the query plan. If these values represent the typical ones with which the procedure is subsequently called, then the procedure benefits from the query plan every time that it compiles and executes. If parameter values on the procedure are frequently atypical, forcing a recompile of the procedure and a new plan based on different parameter values can improve performance.
SQL Server features statement-level recompilation of procedures. When SQL Server recompiles stored procedures, only the statement that caused the recompilation is compiled, instead of the complete procedure.
If certain queries in a procedure regularly use atypical or temporary values, procedure performance can be improved by using the RECOMPILE query hint inside those queries. Since only the queries using the query hint will be recompiled instead of the complete procedure, SQL Server's statement-level recompilation behavior is mimicked. But in addition to using the procedure's current parameter values, the RECOMPILE query hint also uses the values of any local variables inside the stored procedure when you compile the statement. For more information, see Query Hint (Transact-SQL).
WITH RECOMPILE Option
If this option is used when the procedure definition is created, it requires CREATE PROCEDURE permission in the database and ALTER permission on the schema in which the procedure is being created.
If this option is used in an EXECUTE statement, it requires EXECUTE permissions on the procedure. Permissions are not required on the EXECUTE statement itself but execute permissions are required on the procedure referenced in the EXECUTE statement. For more information, see EXECUTE (Transact-SQL).
RECOMPILE Query Hint
This feature is used when the procedure is created and the hint is included in Transact-SQL statements in the procedure. Therefore, it requires CREATE PROCEDURE permission in the database and ALTER permission on the schema in which the procedure is being created.
sp_recompile System Stored Procedure
Requires ALTER permission on the specified procedure.
Connect to the Database Engine.
From the Standard bar, click New Query.
Copy and paste the following example into the query window and click Execute. This example creates the procedure definition.
USE AdventureWorks2012; GO IF OBJECT_ID ( 'dbo.uspProductByVendor', 'P' ) IS NOT NULL DROP PROCEDURE dbo.uspProductByVendor; GO CREATE PROCEDURE dbo.uspProductByVendor @Name varchar(30) = '%' WITH RECOMPILE AS SET NOCOUNT ON; SELECT v.Name AS 'Vendor name', p.Name AS 'Product name' FROM Purchasing.Vendor AS v JOIN Purchasing.ProductVendor AS pv ON v.BusinessEntityID = pv.BusinessEntityID JOIN Production.Product AS p ON pv.ProductID = p.ProductID WHERE v.Name LIKE @Name;
To recompile a stored procedure by using the WITH RECOMPILE option
Select New Query, then copy and paste the following code example into the query window and click Execute. This executes the procedure and recompiles the procedure's query plan.
USE AdventureWorks2012; GO EXECUTE HumanResources.uspProductByVendor WITH RECOMPILE; GO
To recompile a stored procedure by using sp_recompile
Select New Query, then copy and paste the following example into the query window and click Execute. This does not execute the procedure but it does mark the procedure to be recompiled so that its query plan is updated the next time that the procedure is executed.
USE AdventureWorks2012; GO EXEC sp_recompile N'dbo.uspProductByVendor'; GO