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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 INDEX statementUse the CREATE INDEX statement to create an index for one or more columns in a table, or on values returned by a UDR that uses column values as arguments.
Index-type optionsUse the DISTINCT or UNIQUE and CLUSTER options of the CREATE INDEX statement to specify the characteristics of the index.
How indexes affect primary-key, unique, and referential constraintsThe database server creates internal B-tree indexes for primary-key, unique, and referential constraints. If a primary-key, unique, or referential constraint is added after the table is created, any user-created indexes on the constrained columns are used, if appropriate.

How indexes affect primary-key, unique, and referential constraints

The database server creates internal B-tree indexes for primary-key, unique, and referential constraints. If a primary-key, unique, or referential constraint is added after the table is created, any user-created indexes on the constrained columns are used, if appropriate.

An appropriate index is one that indexes the same columns that are used in the primary-key, referential, or unique constraint.

If an appropriate user-created index is not available, the database server creates a nonfragmented internal index on the constrained column or columns.