Xoql: object query Markup language

Modern corporate information systems (CIS) are designed by employing object-oriented paradigm and concepts. This approach is often applied both to implement client applications and to build a server component (target DBMS). The application of object-oriented design pattern in software development enables to save business objects from RAM to persistent memory. This paper focuses on XOQL (XML Object Query Language) - an object query language that uses XML to describe syntax. This article presents a deep and comprehensive review of existing publications. Abundance of examples enables to demonstrate various currently available languages. This paper suggests a feasible option to present basic syntactic constructions of object query language in the form of XML-documents. Prior to syntax design the optimality criteria have been formulated (these are described in detail in this paper). Query language syntax extensions are outlined in addition to basic ones, as well as extension approaches by involving proprietary constructions. An optimal language structure is presented accompanied by descriptions of tags, attributes and admissible values. At the end of this article there are plenty of examples of various common queries.