GN is used to retrieve the next segment that satisfies the specified SSA, searching from current position. After locating the segment, the current position is updated for sequential processing. If no current position established in the DB, GN acts like GU (i.e., searching from the beginning). Sequential retrieval in hierarchy DB is always from top to bottom and from left to right, i.e. pre-order retrieval in a tree.

GHN locks the returned segment for sequential write operation on it, in addition to GN. GHN is not applicable for GSAM.