SPI_scroll_cursor_move skips over some number of rows
in a cursor. This is equivalent to the SQL command
portal containing the cursor
one of FETCH_FORWARD, FETCH_BACKWARD, FETCH_ABSOLUTE or FETCH_RELATIVE
number of rows to move for FETCH_FORWARD or FETCH_BACKWARD; absolute row number to move to for FETCH_ABSOLUTE; or relative row number to move to for FETCH_RELATIVE
SPI_processed is set as in
SPI_execute if successful.
SPI_tuptable is set to NULL, since
no rows are returned by this function.
See the SQL FETCH command for details of the interpretation of the direction and count parameters.
Direction values other than FETCH_FORWARD may fail if the cursor's plan was not created with the CURSOR_OPT_SCROLL option.