Statistics Properties (General Page)
Statistics are used by the query optimizer to calculate the best query plan. When automatic statistics is enabled (the default), SQL Server automatically retains statistics that it finds useful.
Use the Statistics Properties (General Page) to add or remove columns to the statistics and to update the statistics. Updating the statistics is an important maintenance action if you have turned off the automatic statistics feature.
Options
- Table Name
Displays the name of the table described by the statistics.
- Statistics Name
Displays the name of the database object where the statistics are stored. Statistics unrelated to an index, which were created automatically by SQL Server, have names that start with _WA_Sys.
- Statistics Columns
This grid shows the columns described by this set of statistics. All values in the grid are read-only.
- Name
Displays the name of the column described by the statistics. This can be a single column or a combination of columns in a single table.
- Data Type
Indicates the data type of the columns described by the statistics.
- Size
Size of the data type for each column.
- Identity
Indicates an identity column when checked.
- Allow Nulls
Indicates whether the column accepts null values.
- Add
Add additional columns from the table to the statistics grid.
- Remove
Remove the selected column from the statistics grid.
- Move Up
Move the selected column to an earlier location in the statistics grid. The column's location in the grid can substantially affect the usefulness of the statistics.
- Move Down
Move the selected column to a later location in the statistics grid. The column's location in the grid can substantially affect the usefulness of the statistics.
- Statistics for these columns were last updated:
Indicates how old the statistics are. Statistics are more valuable when they are current. Update statistics after large changes to the data. Statistics for tables that have a consistent distribution of data need to be updated less frequently.
- Update statistics for these columns
Check to update the statistics when the dialog box is closed.