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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.
Analyzing query plans with SET EXPLAIN outputYou can use SET EXPLAIN output to study the query plans of an application. The output of the SET EXPLAIN statement shows decisions that the query optimizer makes. It shows whether parallel scans are used, the maximum number of threads required to answer the query, and the type of join used for the query.

Analyzing query plans with SET EXPLAIN output

You can use SET EXPLAIN output to study the query plans of an application. The output of the SET EXPLAIN statement shows decisions that the query optimizer makes. It shows whether parallel scans are used, the maximum number of threads required to answer the query, and the type of join used for the query.

You can restructure a query or use OPTCOMPIND to change how the optimizer treats the query.