Optimization and Performance
The optimization feature collects statistics that are used by the query optimizer to determine the best query execution plan (QEP) to use for your queries.
Follow these optimization guidelines:
• Periodically run optimization on all your databases to generate statistics for columns that are keys or indexed. List the other columns you need as an argument to this command.
• Run full optimization statistics on columns referenced in WHERE clauses of strategic queries that are having problems.
• For very large tables, create statistics based on sample data.
• When there are significant changes to your data distribution, run optimization on the affected columns.
• Do not collect excessive statistics, because you build up large optimizer tables with unused data.
• Run system modification after every optimization.
To perform optimization, use the optimizedb command, Director, or VDBA.
Last modified date: 04/03/2024