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Server configuration: query governor cost limit

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Applies to: SQL Server

This article describes how to configure the query governor cost limit server configuration option in SQL Server by using SQL Server Management Studio or Transact-SQL. The cost limit option specifies an upper limit on the estimated cost allowed for a given query to run. Query cost is an abstract figure determined by the query optimizer based on estimated execution requirements such as CPU time, memory, and disk I/O. It refers to the estimated elapsed time, in seconds, that would be required to complete a query on a specific hardware configuration. This abstract figure doesn't equate to the time required to complete a query on the running instance. It should be treated as a relative measure. The default value for this option is 0, which sets the query governor to off. Setting the value to 0 allows all queries to run without any time limitation. If you specify a nonzero, nonnegative value, the query governor disallows execution of any query that has an estimated cost that exceeds that value.

Recommendations

This option is an advanced option and should be changed only by an experienced database administrator or certified SQL Server professional.

To change the value query governor cost limit on a per-connection basis, use the SET QUERY_GOVERNOR_COST_LIMIT statement.

Permissions

Execute permissions on sp_configure with no parameters or with only the first parameter are granted to all users by default. To execute sp_configure with both parameters to change a configuration option or to run the RECONFIGURE statement, a user must be granted the ALTER SETTINGS server-level permission. The ALTER SETTINGS permission is implicitly held by the sysadmin and serveradmin fixed server roles.

Use SQL Server Management Studio

  1. In Object Explorer, right-click a server and select Properties.

  2. Select the Connections page.

  3. Select or clear the Use query governor to prevent long-running queries check box.

    If you select this check box, in the box below, enter a positive value, which the query governor uses to disallow execution of any query with an estimated cost exceeding that value.

Use Transact-SQL

  1. Connect to the Database Engine.

  2. From the Standard bar, select New Query.

  3. Copy and paste the following example into the query window and select Execute. This example shows how to use sp_configure to set the value of the query governor cost limit option to an estimated query cost upper limit of 120.

    USE master;
GO

EXECUTE sp_configure 'show advanced options', 1;
GO

RECONFIGURE;
GO

EXECUTE sp_configure 'query governor cost limit', 120;
GO

RECONFIGURE;
GO

EXECUTE sp_configure 'show advanced options', 0;
GO

RECONFIGURE;
GO

For more information, see Server configuration options.

Follow up: After you configure the query governor cost limit option

The setting takes effect immediately without restarting the server.

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