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)

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Detailed Description

#include <rel/rdb.h>

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Function Documentation

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:

RDB_INVALID_ARGUMENT_ERROR

name is not a valid index name.

RDB_ELEMENT_EXIST_ERROR

An index with name name already exists.

RDB_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.

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:

RDB_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.

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