Minmax Statistics
Minmax statistics are “cheaper” than full statistics to create. In most cases they require only one scan of the entire table. Statistics created have information only about minimum and maximum values for a column. This can be acceptable if the distribution of values in the column is reasonably even. However, if the values of a particular column are skewed, minmax statistics can mislead the query optimizer and result in poor query plan choices.
Note: Minmax statistics cannot be created using the CREATE STATISTICS statement.
Example: Generate Statistics with Only Minimum and Maximum Values for a Table
This example generates statistics with only minimum and maximum values for the employee table:
optimizedb -zx empdata -remployee
In Director:
1. Open the Generate Statistics dialog
2. Click Specify Tables, and then click the Tables button.
3. Select the employee table and click OK.
4. Click Options under Select a page.
5. Select Determine Min/Max values for each Column, and then click OK.