Why we execute Update Statistics?

1.	Why we execute Update Statistics?
Answer» By Default, SQL SERVER works in Simple Parameterization where SQL Server internally will add parameters to an SQL statement EXECUTED without parameters so that it can try to reuse a cached execution plan. But Simple parametrization has lots of limitation but did not work in the following cases:- JOIN IN BULK INSERT UNION INTO DISTINCT TOP GROUP BY HAVING COMPUTE Sub Queries To FORCE SQL Server to have Auto Parameterization for EVERY SQL execution, You need to enable Force Parameterization at the database level. Force Parameterization settings need proper testing as it may also create an adverse IMPACT on performance.

Answer»

By Default, SQL SERVER works in Simple Parameterization where SQL Server internally will add parameters to an SQL statement EXECUTED without parameters so that it can try to reuse a cached execution plan. But Simple parametrization has lots of limitation but did not work in the following cases:-

JOIN
IN
BULK INSERT
UNION
INTO
DISTINCT
TOP
GROUP BY
HAVING
COMPUTE
Sub Queries

To FORCE SQL Server to have Auto Parameterization for EVERY SQL execution, You need to enable Force Parameterization at the database level.

Force Parameterization settings need proper testing as it may also create an adverse IMPACT on performance.

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