![]() ![]() It tracks execution metrics for stored procedures. sys.dm_exec_procedure_stats- This DMV is only available in SQL Server 2008 and higher.sys.dm_exec_query_stats – This DMV is helpful to see the top statements on your SQL Server, regardless of whether they’re part of a procedure or not.When I talk about impact on the execution plan cache, I’ll refer to two DMVs: Handle with care! Useful Dynamic Management Views If you’ve got big questions in those areas, feel free to suggest it for a future post in the comments.ĭisclaimer: Recompile hints can kill your performance by lighting your CPUs on fire when used incorrectly. To keep things relatively simple, I’m just discussing how this applies to stored procedures today–this post doesn’t cover other forms of parameterized (or non parameterized) queries. I’ll give some pros and cons for each method and explain what’s useful and what’s worth avoiding. This post runs through common options you have to nudge (or whack) SQL Server into generating a fresh execution plan. (Not sure what parameter sniffing is? Learn from this blog post or this 50 minute free video.) You must decide: what hint or command do you use, and where do you put it? What trade-offs are you making when it comes to being able to performance tune your SQL Server in the future? We should use RECOMPILE option only when the cost of generating a new execution plan is much less then the performance improvement which we got by using RECOMPILE option.When you identify that parameter sniffing is a problem, you need to test whether implementing ‘recompile’ hints will help plan quality. This is because of the WITH RECOMPILE option, here each execution of stored procedure generates a new execution plan. Here you see the better execution plan and great improvement in Statistics IO. ![]() Now execute this stored procedure as: set statistics IO on ![]() Now again creating that stored procedure with RECOMPILE option. Here when we execute stored procedure again it uses the same execution plan with clustered index which is stored in procedure cache, while we know that if it uses non clustered index to retrieve the data here then performance will be fast. Now executing the same procedure with different parameter value: set statistics IO on The output of this execution generates below mention statistics and Execution plan: Select address,name from xtdetails where execute this stored procedure as: set statistics IO on Now create stored procedure as shown below: create procedure as varchar(50)) Set into xtdetails table xtdetails contains 10000 rows, where only 10 rows having name = asheesh and address=Moradabad. Now, I am inserting the data into this table: declare as int Ĭreate clustered index IX_xtdetails_id on xtdetails(id)Ĭreate Nonclustered index IX_xtdetails_address on xtdetails(address) In this case if we reuse the same plan for different values of parameters then performance may degrade.įor Example, create a table xtdetails and create indexes on them and insert some data as shown below: CREATE TABLE. But sometimes plans generation depends on parameter values of stored procedures. If plan found in cache then it reuse that plan that means we save our CPU cycles to generate a new plan. ![]() If we again execute the same procedure then before creating a new execution plan sql server search that plan in procedure cache. When we execute stored procedure then sql server create an execution plan for that procedure and stored that plan in procedure cache. Here i am focusing on why we use WITH RECOMPILE option. Some time, we also use WITH RECOMPILE option in stored procedures. We use stored procedures in sql server to get the benefit of reusability. Today here, I am explaining the Use of Recompile Clause in SQL Server Stored Procedures. ![]()
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