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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™.
ALTER INDEX statementUse the ALTER INDEX statement to change the clustering attribute of an existing index. This statement is an extension to the ANSI/ISO standard for SQL.
TO NOT CLUSTER Option The TO NOT CLUSTER option drops the cluster attribute on the specified index without affecting the physical order of rows in the table.

TO NOT CLUSTER Option

The TO NOT CLUSTER option drops the cluster attribute on the specified index without affecting the physical order of rows in the table.

Because no more than one clustered index can exist on a given table, you must use the TO NOT CLUSTER option to release the cluster attribute from one index before you assign it to another index on the same table.

Example of dropping the clustering attribute

The following statements illustrate how to remove clustering from one index and how a second index physically reclusters the table:

CREATE UNIQUE INDEX ix_ord ON orders (order_num);

CREATE CLUSTER INDEX ix_cust ON orders (customer_num); 
. . .
ALTER INDEX ix_cust TO NOT CLUSTER; 
 
ALTER INDEX ix_ord TO CLUSTER;

The first two statements create indexes for the orders table and cluster the physical table in ascending order on the customer_num column. The last two statements recluster the physical table in ascending order on the order_num column.