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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.
DBA control of resources for PDQ and DSS queriesTo manage the total amount of resources that the database server allocates to parallel database and decision-support (DSS) queries, the database server administrator can set the environment variable and configuration parameters.
Controlling resources allocated to PDQTo control resources allocated to PDQ, you can set the PDQPRIORITY environment variable. The queries that do not set the PDQPRIORITY environment variable before they issue a query do not use PDQ. In addition, to place a ceiling on user-specified PDQ priority levels, you can set the MAX_PDQPRIORITY configuration parameter.

Controlling resources allocated to PDQ

To control resources allocated to PDQ, you can set the PDQPRIORITY environment variable. The queries that do not set the PDQPRIORITY environment variable before they issue a query do not use PDQ. In addition, to place a ceiling on user-specified PDQ priority levels, you can set the MAX_PDQPRIORITY configuration parameter.

When you set the PDQPRIORITY environment variable and MAX_PDQPRIORITY parameter, you exert control over the resources that the database server allocates between OLTP and DSS applications. For example, if OLTP processing is particularly heavy during a certain period of the day, you might want to set MAX_PDQPRIORITY to 0. This configuration parameter puts a ceiling on the resources requested by users who use the PDQPRIORITY environment variable, so PDQ is turned off until you reset MAX_PDQPRIORITY to a nonzero value.