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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.
SQL statementsThis chapter describes the syntax and semantics of SQL statements that are recognized by HCL OneDB™.
CREATE OPAQUE TYPE statementUse the CREATE OPAQUE TYPE statement to create an opaque data type.
Opaque-Type Modifier

Opaque-Type Modifier


Element	Description	Restrictions	Syntax
align_value	Byte boundary on which to align an opaque type that is passed to a user-defined routine. Default is 4 bytes.	Must be 1, 2, 4, or 8, depending on the C definition of the opaque data type and hardware and compiler used to build the object file for the data type	Literal Number
length	Maximum length to allocate for instances of varying-length opaque types. Default is 2 kilobytes.	Must be a positive integer < 32 kilobytes. Do not specify for fixed-length data types. Values that exceed this length return errors.	Literal Number

Modifiers can specify the following optional information for opaque types:

MAXLEN specifies the maximum length for varying-length types.
CANNOTHASH specifies that the database server cannot use the built-in hash function on the opaque type.
ALIGNMENT specifies the byte boundary on which the database server aligns the opaque type.
PASSEDBYVALUE specifies that an opaque type that requires 4 bytes or fewer of storage is passed by value.

By default, opaque types are passed to user-defined routines by reference.