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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.
Optimizer directivesOptimizer directives are comments that tell the query optimizer how to execute a query. You can use optimizer directives to improve query performance.
What optimizer directives areOptimizer directives are specifications formatted as comments that provide information to the query optimizer about how to execute a query.
Optimizer directives that are embedded in queries Optimizer directives embedded in queries are comments in a SELECT statement that provide information to the query optimizer on how to execute a query. You can also place directives in UPDATE and DELETE statements, instructing the optimizer how to access the data.

Optimizer directives that are embedded in queries

Optimizer directives embedded in queries are comments in a SELECT statement that provide information to the query optimizer on how to execute a query. You can also place directives in UPDATE and DELETE statements, instructing the optimizer how to access the data.

Optimizer directives can either be explicit directions (for example, "use this index" or "access this table first"), or they can eliminate possible query plans (for example, "do not read this table sequentially" or "do not perform a nested-loop join").