offset is an optional parameter which is only evaluated (and required) if whence is either SESAM_SEEK_RELATIVE or SESAM_SEEK_ABSOLUTE.
When using "scrollable" cursors, the cursor can be freely positioned on the result set. If the whence parameter is omitted, the global default values for the scrolling type (initialized to: SESAM_SEEK_NEXT, and settable by sesam_seek_row()) are used. If whence is supplied, its value replaces the global default.