ASA SQL Reference
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ESTIMATE function [Miscellaneous]

Function 

Provides selectivity estimates for the query optimizer, based on specified parameters.

Syntax 

ESTIMATE ( column-name [, value  [, relation-string ] ] )

Parameters 

column-name    The column used in the estimate.

value    The value to which the column is compared.

relation-string     The comparison operator used for the comparison, enclosed in single quotes; the default is '='.

Standards and compatibility 

• SQL/92    Vendor extension.

• SQL/99    Vendor extension.

• Sybase    Not supported in Adaptive Server Enterprise.

See also 

INDEX_ESTIMATE function [Miscellaneous]

ESTIMATE_SOURCE function [Miscellaneous]

Example 

The following statement returns the percentage of emp_id values estimated to be greater than 200. The precise value depends on the actions you have carried out on the database.

SELECT FIRST ESTIMATE( emp_id, 200, '>' )
   FROM employee