Update Statistics Task (Maintenance Plan)

Applies to: SQL Server

Use the Update Statistics Task dialog to update Microsoft SQL Server information about the data in the tables and indexes. This task resamples the distribution statistics of each index created on user tables in the database. The distribution statistics are used by SQL Server to optimize navigation through tables during the processing of Transact-SQL statements. To build the distribution statistics automatically, SQL Server periodically samples the data in the corresponding table for each index. This size of the sample is based on the number of rows in the table and the frequency of data modification. Use this option to perform an additional sampling using the specified percentage of data in the tables. SQL Server uses this information to create better query plans.

This task executes the UPDATE STATISTICS statement.

Options

• Connection

  Select the server connection to use when performing this task.

• New

  Create a new server connection to use when performing this task. The New Connection dialog box is described below.

• Databases

  Specify the databases affected by this task.

  • All databases

    Generate a maintenance plan that runs maintenance tasks against all SQL Server databases, except tempdb.

  • All system databases

    Generate a maintenance plan that runs maintenance tasks against each of the SQL Server system databases except tempdb. No maintenance tasks are run against user-created databases.

  • All user databases

    Generate a maintenance plan that runs maintenance tasks against all user-created databases. No maintenance tasks are run against the SQL Server system databases.

  • These specific databases

    Generate a maintenance plan that runs maintenance tasks against only those databases that are selected. At least one database in the list must be selected if this option is chosen.

  Note

  Maintenance plans only run against databases set to compatibility level 80 or higher.

• Object

  Limit the Selection grid to display tables, views, or both.

• Selection

  Specify the tables or indexes affected by this task. Not available when Tables and Views is selected in the Object box.

• All existing statistics

  Update statistics for both columns and indexes.

• Column statistics only

  Only update column statistics.

• Index statistics only

  Only update index statistics.

• Scan type

  Type of scan used to gather updated statistics.

• Full scan

  Read all rows in the table or view to gather the statistics.

• Sample by

  Specify the percentage of the table or indexed view, or the number of rows to sample when collecting statistics for larger tables or views.

• View T-SQL

  View the Transact-SQL statements performed against the server for this task, based on the selected options.

  Note

  When the number of objects affected is large, this display can take a considerable amount of time.

New Connection dialog box

• Connection name

  Enter a name for the new connection.

• Select or enter a server name

  Select a server to connect to when performing this task.

• Refresh

  Refresh the list of available servers.

• Enter information to log on to the server

  Specify how to authenticate against the server.

• Use Windows integrated security

  Connect to an instance of the SQL Server Database Engine with Microsoft Windows Authentication.

• Use a specific user name and password

  Connect to an instance of the SQL Server Database Engine using SQL Server Authentication. This option isn't available.

• User name

  Provide a SQL Server login to use when authenticating. This option isn't available.

• Password

  Provide a password to use when authenticating. This option isn't available.

See also

• UPDATE STATISTICS (Transact-SQL)
• sp_updatestats
• Adaptive Index Defrag