  We address the problem of semantic querying of relational databases (RDB)
modulo knowledge bases using very expressive knowledge representation
formalisms, such as full first-order logic or its various fragments. We propose
to use a first-order logic (FOL) reasoner for computing schematic answers to
deductive queries, with the subsequent instantiation of these schematic answers
using a conventional relational DBMS. In this research note, we outline the
main idea of this technique -- using abstractions of databases and constrained
clauses for deriving schematic answers. The proposed method can be directly
used with regular RDB, including legacy databases. Moreover, we propose it as a
potential basis for an efficient Web-scale semantic search technology.
