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SQL programmingYou can use the HCL OneDB™ implementation of the SQL language to develop applications for HCL OneDB™ database servers.
Guide to SQL: SyntaxThe HCL OneDB™ Guide to SQL: Syntax describes the syntax of the statements, data types, expressions, operators, and built-in functions of the HCL OneDB™ dialect of the SQL language.
Other syntax segmentsThese topics describe syntax segments, which are language elements, such as database object names or optimizer directives, that appear as a subdiagram reference in the syntax diagrams of some SQL or SPL statements.
Optimizer DirectivesThe Optimizer Directives segment specifies keywords that you can use to partially or fully specify the query plan of the optimizer. Use this segment whenever you see a reference to Optimizer Directives in a syntax diagram.
External DirectivesYou can use the SAVE EXTERNAL DIRECTIVES statement to store optimizer directives in the sysdirectives table of the system catalog. HCL OneDB™ applies these external directives automatically to subsequent queries and subqueries that match a specified SELECT statement.

External Directives

You can use the SAVE EXTERNAL DIRECTIVES statement to store optimizer directives in the sysdirectives table of the system catalog. HCL OneDB™ applies these external directives automatically to subsequent queries and subqueries that match a specified SELECT statement.

The EXT_DIRECTIVES configuration parameter and the IFX_EXTDIRECTIVES environment variable can be set to control whether external directives are enabled or disabled for the database server instance or for the session. Setting either of these to zero disables external directives; setting both to 1 enables external directives.

You can also use the EXTDIRECTIVES option of the SET ENVIRONMENT statement to enable or disable external directives during a session. For more information, see Enabling or disabling external directives for a session.