Configure the user connections Server Configuration Option

This topic describes how to set the user connections server configuration option in SQL Server 2012 by using SQL Server Management Studio or Transact-SQL. The user connections option specifies the maximum number of simultaneous user connections that are allowed on an instance of SQL Server. The actual number of user connections allowed also depends on the version of SQL Server that you are using, and also the limits of your application or applications and hardware. SQL Server allows a maximum of 32,767 user connections. Because user connections is a dynamic (self-configuring) option, SQL Server adjusts the maximum number of user connections automatically as needed, up to the maximum value allowable. For example, if only 10 users are logged in, 10 user connection objects are allocated. In most cases, you do not have to change the value for this option. The default is 0, which means that unlimited user connections are allowed.

To determine the maximum number of user connections that your system allows, you can execute sp_configure or query the sys.configuration catalog view.

In This Topic

• Before you begin:

  Recommendations

  Security

• To configure the user connections option, using:

  SQL Server Management Studio

  Transact-SQL

• Follow Up:  After you configure the user connections option

Before You Begin

Recommendations

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

• Using the user connections option helps avoid overloading the server with too many concurrent connections. You can estimate the number of connections based on system and user requirements. For example, on a system with many users, each user would not usually require a unique connection. Connections can be shared among users. Users running OLE DB applications need a connection for each open connection object, users running Open Database Connectivity (ODBC) applications need a connection for each active connection handle in the application, and users running DB-Library applications need one connection for each process started that calls the DB-Library dbopen function.

  Ważne:
  If you must use this option, do not set the value too high, because each connection has overhead regardless of whether the connection is being used. If you exceed the maximum number of user connections, you receive an error message and are not able to connect until another connection becomes available.

Security

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.

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Using SQL Server Management Studio

To configure the user connections option

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

2. Click the Connections node.

3. Under Connections, in the Max number of concurrent connections box, type or select a value from 0 through 32767 to set the maximum number of users that are allowed to connect simultaneously to the instance of SQL Server.

4. Restart SQL Server.

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Using Transact-SQL

To configure the user connections option

1. Connect to the Database Engine.

2. From the Standard bar, click New Query.

3. Copy and paste the following example into the query window and click Execute. This example shows how to use sp_configure to configure the value of the user connections option to 325 users.

USE AdventureWorks2012 ;
GO
EXEC sp_configure 'show advanced options', 1;
GO
RECONFIGURE ;
GO
EXEC sp_configure 'user connections', 325 ;
GO
RECONFIGURE;
GO

For more information, see Server Configuration Options (SQL Server).

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Follow Up: After you configure the user connections option

The server must be restarted before the setting can take effect.

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Zobacz także

Zadania

Configure the user connections Server Configuration Option

Odwołanie

RECONFIGURE (Transact-SQL)

sp_configure (Transact-SQL)

Koncepcje

Server Configuration Options (SQL Server)