Liu, H.C.2025-12-172025-12-172011Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2011; 6588:195-2090302-97431611-3349https://hdl.handle.net/1959.8/151873Motivated by constraint complex values which allow us to represent nested finitely representable sets, we study the expressive power of various query languages over constraint complex value databases. The tools we use come in the form of collapse results which are well established results in the context of first-order logic. We show that active-generic collapse carries over to second-order logic for structures with o-minimality and any relational signature in the complex value model. We also consider the problem of safety in the context of embedded finite complex value models and constraint complex value databases.enCopyright 2011 Springer-Verlag Berlin Heidelbergcomplex valuesexpressive powerfirst order logicminimalityover-constraintsecond-order logicgeographic information systemquery languageconstraint complextquery classJournal article10.1007/978-3-642-20152-3_152-s2.0-79955101948