Any database, no matter how complex, can be represented as a set of binary-relationships. Consequently, a structure which can store such binary-relationships is logically sufficient as the storage mechanism for a general purpose database management system. For certain applications, the advantages of using such a structure would appear to outweigh the disadvantages. Surprisingly, however, very few systems have been built which use a binary-relational storage structure. The main reason would appear to be the difficulty of implementing such structures efficiently.