## 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