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AdministeringIn addition to administering the database server, you can tune performance, replicate data, and archive data.
System administrationThese topics contain concepts, procedures, and reference information for database and database server administrators to use for managing and tuning HCL OneDB™ database servers.
Performance GuideThe HCL OneDB™ Performance Guide describes how to configure and operate your HCL OneDB™ database server to improve overall system throughput and to improve the performance of SQL queries.
Parallel database query (PDQ)You can manage how the database server performs PDQ and you can monitor the resources that the database server uses for PDQ.
Managing PDQ queriesThe database server administrator, the writer of an application, and the users all have a certain amount of control over the amount of resources that OneDB allocates to processing a query. The database server administrator exerts control through the use of configuration parameters. The application developer or the user can exert control through an environment variable or SQL statement.
User control of PDQ resourcesTo indicate the PDQ priority of a query, you can set the PDQPRIORITY environment variable or execute the SET PDQPRIORITY statement prior to issuing a query. These PDQ priority options allow you to request a certain amount of parallel-processing resources for the query.

User control of PDQ resources

To indicate the PDQ priority of a query, you can set the PDQPRIORITY environment variable or execute the SET PDQPRIORITY statement prior to issuing a query. These PDQ priority options allow you to request a certain amount of parallel-processing resources for the query.

The resources that you request and the amount of resources that the database server allocates for the query can differ. This difference occurs when the database server administrator uses the MAX_PDQPRIORITY configuration parameter to put a ceiling on user-requested resources, as the following topic explains.