![]() ![]() This is one level simpler (and I would say quite a bit simpler) than the first option. ![]() You’ll need to spend some time digging through the Microsoft documentation to get one working. This is the most difficult option and usually takes a fair amount of trial and error. It should be noted, you will need to drop a plan guide if you applied it to a stored procedure and perform an update to the stored procedure at some later point in time. There are several options for how to create plan guides and I’ll list these out here. With plan guides you can specify an execution plan as XML and force the query to use that plan whenever it is encountered. Plan guides are generally complex to create and as a result some people shy away from them. Query store must be enabled while the good plan was in use in order to force the good plan. Query store is currently not enabled by default except for Azure SQL Database. You must have query store enabled to do this. If you have query store enabled (available on SQL Server 2016 and later), you can force a good plan to be used whenever a particular query is executed. This scenario requires that you have the good plan. Forcing a Good PlanĪnother option for dealing with bad plans is to force a known good plan. This will cause a new plan to generate for all statements in the stored procedure. If the query with the bad plan is in a stored procedure, you can call sp_recompile on the stored procedure. If you are reading this because you are a SQLGrease user, you can generate the DBCC FREEPROCCACHE command by clicking the “Copy flush command” button. This will prevent you from freeing every plan from the cache (good or bad). If you plan to use DBCC FREEPROCCACHE I highly recommend passing a plan handle as input. You can free a bad plan from the cache with either DBCC FREEPROCCACHE or by recompiling a stored procedure. In the case of parameter sniffing, this option has a higher chance of solving problems. In some cases, freeing a bad plan from the cache may solve your problems. ![]() In this post I’ll cover some zero code change options and some of their pros-cons and limitations. Causes of this (stale statistics, parameter sniffing) won’t be covered in this post, but options to get around this will. In reality there are other factors that can cause an efficient plan to generate for one execution but not for other executions. In an ideal world all executions of the same query should perform well with one plan. This eliminates the need for subsequent calls to the same query to generate the plan. To avoid the expense, SQL Server attempts to cache a plan once it is generated. Hope it will give you enough idea of these concepts used in the SQL Server.SQL Server does the best it can to generate an efficient execution plan when a query is executed. ![]() We can't use WITH RECOMPILE and FOR REPLICATION options together in a Single stored procedure. So it optimises the execution time by regenerating each time different query plan for the the stored procedure.įOR REPLICATION:Whern the stored procedure is created with the option FOR REPLICATION, it means this stored pocedure will be execution in case of Replication happens. The advanatgaes of having the different execution plan each time is that the data in the execution will be distributed differently in case of parameters passed to the stored procedure. Then what is the advantage of havinf different execution plan each time while execution of the stored procedure? Wont it take more time to create the execution plan each time? The answer is no. WITH RECOMPILE: This option in SQL Server is used to generate a new query plan every time while executing the stored procedure. WITH ENCRYPTION: Is the key word used in stored procedure to make the text as the enrypt format for the stored procedure so that the text of stored procedure will not be open as in text format. ![]()
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