Index functions

Functions
int	RDB_create_table_index (const char *name, RDB_object *tbp, int idxcompc, const RDB_seq_item idxcompv[], int flags, RDB_exec_context *ecp, RDB_transaction *txp)
int	RDB_drop_table_index (const char *name, RDB_exec_context *ecp, RDB_transaction *txp)
RDB_bool	RDB_expr_is_serial (const RDB_expression *exp)

Detailed Description

#include <rel/rdb.h>

Function Documentation

RDB_create_table_index()

int RDB_create_table_index	(	const char *	name,
		RDB_object *	tbp,
		int	idxcompc,
		const RDB_seq_item	idxcompv[],
		int	flags,
		RDB_exec_context *	ecp,
		RDB_transaction *	txp
	)

RDB_create_table_index creates an index with name name for the table specified by tbp over the attributes specified by idxcompc and idxcompv. The flags argument must be either 0 or RDB_ORDERED. If flags is 0, a hash index is created. If flags is RDB_ORDERED, a B-tree index is created.

Functions which read tuples from a table (like RDB_table_to_array and RDB_extract_tuple) try to use available indexes to achieve better performance.

Returns

RDB_OK on success, RDB_ERROR if an error occurred.

Errors:

invalid_argument_error

name is not a valid index name.

element_exist_error

An index with name name already exists.

name_error

An attribute specified by idxcompv does not appear in the table.

The call may also fail for a system error, in which case the transaction may be implicitly rolled back.

RDB_drop_table_index()

int RDB_drop_table_index	(	const char *	name,
		RDB_exec_context *	ecp,
		RDB_transaction *	txp
	)

RDB_drop_table_index drops the index specified by name.

Returns

RDB_OK on success, RDB_ERROR if an error occurred.

Errors:

not_found_error

An index with name name does not exist.

The call may also fail for a system error, in which case the transaction may be implicitly rolled back.