The authors consider relational databases organized over an ordered domain with some additional relations - a typical example is the ordered domain of rational numbers together with the operation of addition. In the f...The authors consider relational databases organized over an ordered domain with some additional relations - a typical example is the ordered domain of rational numbers together with the operation of addition. In the focus of our study are the FO (first-order) queries that are invariant under order-preserving permutations-such queries are called order-generic. It was discovered that for some domains order-generic FO queries fail to express more than pure order queries. The collapse result theorem was proved for locally genetic queries over a linearly ordered domain with the Pseudo finite Homogeneity Property (or / and the Isolation Property) by Belegradek et al.. Here the authors consider a circularly ordered domain and prove the collapse result theorem over a quasi circularly minimal domain.展开更多
文摘The authors consider relational databases organized over an ordered domain with some additional relations - a typical example is the ordered domain of rational numbers together with the operation of addition. In the focus of our study are the FO (first-order) queries that are invariant under order-preserving permutations-such queries are called order-generic. It was discovered that for some domains order-generic FO queries fail to express more than pure order queries. The collapse result theorem was proved for locally genetic queries over a linearly ordered domain with the Pseudo finite Homogeneity Property (or / and the Isolation Property) by Belegradek et al.. Here the authors consider a circularly ordered domain and prove the collapse result theorem over a quasi circularly minimal domain.