_rewind_extfn

The _rewind_extfn v4 API method restarts a result set at the beginning of the table.

Declaration

void _rewind_extfn(
a_v4_extfn_table_context *cntxt, 
)

Usage

This function is an optional entry point. The UDF implements the _rewind_extfn method when the result table is rewound to the beginning. The UDF should consider implementing this method only if it can provide the rewind functionality in an efficient and cost-effective manner.

If a UDF chooses to implement the _rewind_extfn method, it should tell the consumer during the state EXTFNAPIV4_STATE_OPTIMIZATION by setting the EXTFNAPIV4_DESCRIBE_PARM_TABLE_HAS_REWIND parameter for argument 0.

The UDF may decide not to provide the rewind functionality, in which case the server compensates and provides the functionality.

Note: The server can choose not to call the _rewind_extfn method to perform the rewind.

Parameters

Parameter Description
cntxt The procedure context object

Returns

No return value.

Parent topic: Table Functions (a_v4_extfn_table_func)