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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.
Statement cache directiveUse the statement cache directive to prevent the statement from being stored in the statement cache. The AVOID_STMT_CACHE optimizer directive forces the optimizer to reoptimize the statement every time that the statement is run.

Statement cache directive

Use the statement cache directive to prevent the statement from being stored in the statement cache. The AVOID_STMT_CACHE optimizer directive forces the optimizer to reoptimize the statement every time that the statement is run.


Element	Description	Restrictions	Syntax
comments	Text documenting the directive	Must appear between comment symbols	Character string

The AVOID_STMT_CACHE directive is useful for those statements whose query plans can change significantly depending on the values of the placeholders that are passed to the database server when the statements are run. Using a cached query plan for those sorts of statements might result in poor performance.

For example, the following statement is not stored in the statement cache:

SELECT {+AVOID_STMT_CACHE}
    c.customer_num, c.lname, o.order_date
    FROM customer c, order o
    WHERE c.customer_num = o.customer_num;