01037naa a2200169 a 450000100080000000500110000800800410001910000200006024501010008026000090018130000150019050000490020552004610025470000220071570000200073777301100075710032612007-12-19       1994    bl uuuu     u00u1 u    #d1 aSILVA, A. S. da  aSobre a manutenção da consistência de representações relacionais otimizadas de esquemas ER.  c1994  ap.276-292.  aSBBD'94. Editado por Caetano Traina Júnior.  aThis paper discusses the problem of maintaining the semantic consistency of optimized relational represeentations of entity-relationship schemas produced by colapsing entity and relationship schemas according to common database design heuristics. An intrarelation type of integrity cconstraint, called null dependency, is proposed which enforces the correction of such relational representations according to the semantics of the entity-relationship model.1 aLAENDER, A. H. F.1 aCASANOVA, M. A.  tIn: SIMPÓSIO BRASILEIRO DE BANCO DE DADOS, 9., 1994, São Carlos. Anais... São Carlos: USP-ICMSC, 1994.