Szukana fraza: [Abstract = "A comparison is made between problem\-oriented databases for multistage decision making and general\-purpose databases. An exemplary problem\-oriented database IDEN for supporting the process of multistage identification is discussed in detail. An equivalence condition for problem\-oriented databases is formulated and then the equivalence with respect to data structures and operations is proved for hierarchical, network and relational models of the IDEN database."]