Open Problems

Abstract

We have presented an extended ER model together with relevant theoretical investigations. Although the extensions are simple they are very useful for practical database modeling. We have developed some theoretical fundamentals and illustrated that this model has a sound, well-founded theory similar to that of the relational model.

Ay, in this though I pledge my faith unswerving, Here wisdom speaks its final word and true, None is of freedom or of life deserving Unless he daily conquers it anew. With dangers thus begirt, defying fears, Childhood, youth, age shall strive through strenuous years. Such busy, teeming throngs I long to see, Standing on freedom’s soil, a people free. Then to the moment could I say: Linger you now, you are so fair! Now records of my earthly day No flight of aeons can impair — Foreknowledge comes, and fills me with such bliss, I take my joy, my highest moment this.

Goethe, Faust II, The Great Outer-Court of the Palace