6/16/2023 0 Comments Sql with recompile![]() Keep in mind with version 15 of SQL Server, Microsoft introduced a feature called “Table Variable Deferred Compilation” that solves the problem mentioned here, without the use of option RECOMPILE. If you find your Table Variable queries are not performing well then you might consider adding the optimizer hint RECOMPILE to see if your query starts performing better. Once the optimizer has a better guess at the actual number of rows in a table variable, then it has a much better chance of picking an operator that works well for larger record sets, like a Hash Match for a join operation. 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. The estimated recompile threshold starts an automatic recompile for the query when the estimated number of indexed column changes have been made to a table by running one of the following statements: UPDATE DELETE MERGE INSERT Specifying KEEP PLAN makes sure a query won't be recompiled as frequently when there are multiple updates to a table. This will allow the optimizer to know how many rows are in the table variable. We use stored procedures in sql server to get the benefit of reusability. Jump to Simple Examples to skip the details of the syntax and get to a quick example of a basic stored procedure. CLR integration does not apply to Azure SQL Database. Therefore, to improve the performance of your code that use table variables that contain lots of rows, you should consider adding the optimizer hint RECOMPILE as shown below: SELECT O., TV.īy adding the optimizer hint RECOMPILE, a statement that uses a table variable will be recompiled after the temporary table has been populated. NET Framework CLR into SQL Server is discussed in this topic. Operators that perform well for small numbers of rows do not always scale when large numbers of rows are involved. If we know that a statement returns a varying amount of data (based on the parameters supplied) then we can use the SQL Server 2005 feature WITH RECOMPILE to tell SQL Server that the statement being executed should have it’s own plan created and that prior plans (if they exist) should not reuse the statement. Having an estimated row count of 1 works well for operators that have small row counts, like a NESTED LOOP operator for a join operation. This occurs because table variables don’t have statistics. This is because when a batch is compiled the table variable has yet to be populated with any rows, and therefore the optimizer uses an estimated row count of 1 for table variables. ![]() Thom A at 14:50 3 But WHY It is highly unlikely - in this scenario - that recompiling does anything useful. Your requirement is like asking how to define a query where the FROM is defined before the SELECT. Table Variables have been known to run slowly when the table variable contains lots of rows. As per the syntax documentation the WITH clause, and the procedure options (with includes RECOMPILE ), goes before the AS. Should ruby-plsql be recompiling database code that has been left in an invalid state (Eg a related table changes etc).
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