Controlling Query Processing

Any user can set limits on the amount of time spent processing a particular query. Users with the SET ANY PUBLIC OPTION system privilege can give certain users’ queries priority over others, or change processing algorithms to influence the speed of query processing.

• Setting Query Time Limits
  Set the MAX_QUERY_TIME option to limit the time a query can run. If a query takes longer to execute than the MAX_QUERY_TIME , SAP Sybase IQ stops the query with an appropriate error.
• Setting Query Priority
  Setting query priority options assigns query processing priorities by user.
• Setting Query Optimization Options
  Optimization options affect query processing speed.
• Setting User-Supplied Condition Hints
  Selectivity hints help the optimizer choose an appropriate query strategy.
• Monitoring Workloads
  Use the stored procedures that monitor table, column, and index usage for better query performance.