Abstract
Database manipulating systems (DMS) formalize operations on
relational databases like adding new tuples or deleting
existing ones. To ensure sufficient expressiveness for
capturing practical database systems, DMS operations
incorporate guarding expressions first-order formulas over
countable value domains. Those features impose infinite
state, infinitely branching processes thus making automated
reasoning about properties like the reachability of states
intractable. Most recent approaches, therefore, restrict DMS
to obtain decidable fragments. Nevertheless, a comprehensive
semantic framework capturing full DMS, yet incorporating
effective notions of data abstraction and process equivalence
is an open issue. In this paper, we propose DMS process
semantics based on principles of abstract interpretation. The
concrete domain consists of all valid databases, whereas the
abstract domain employs different constructions for unifying
sets of databases being semantically equivalent up to
particular fragments of the DMS guard language. The
connection between abstract and concrete domains is
effectively established by homomorphic mappings whose
properties and restrictions depend on the expressiveness of
the DMS fragment under consideration. We instantiate our
framework for canonical DMS fragments and investigate
semantical preservation of abstractions up to bisimilarity,
being one of the strongest equivalence notions for
operational process semantics.
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