OPTIMIZERINFORMATION 
Definition
The system table OPTIMIZERINFORMATION contains the information about value distributions that is determined by the UPDATE STATISTICS statement and used by the SQL Optimizer.
Structure
OPTIMIZERINFORMATION
SCHEMANAME |
CHAR(32) |
Name of the schema of the table |
TABLENAME |
CHAR(32) |
Name of the table |
COLUMNNAME |
CHAR(32) |
Name of a single, non-indexed column |
INDEXNAME |
CHAR(32) |
Name of the index |
DISTINCTVALUECOUNT |
FIXED(10) |
Number of distinct values in column, index, or primary key |
CALCULATEDSIZE |
FIXED(10) |
Memory requirements of (primary key) index calculated by last UPDATE STATISTICS (KB) |
See also:
SQL Reference Manual, UPDATE STATISTICS Statement (update_statistics_statement), EXPLAIN Statement (explain_statement)
Concepts of the Database System, SQL Optimizer
Database Administration in CCMS, 
SQL Optimizer in
CCMS, Scheduling Updates of
the SQL Optimizer Statistics