Papers by Euclid Keramopoulos
The GOQL Graphical Query Language
International Journal of Computers and Applications, 2002
The authors present a graphical query language, GOQL (Graphical Object Query Language), for objec... more The authors present a graphical query language, GOQL (Graphical Object Query Language), for object-oriented data base systems, in general, and the object model of ODMG 2.0, in particular. A detailed literature survey of related work is given, and an analysis ...
KINISIS, a Graphical Xquery Language
ABSTRACT EXtensible Markup Language (XML) tends to become a standard way of data interchanging on... more ABSTRACT EXtensible Markup Language (XML) tends to become a standard way of data interchanging on the Web. XQuery is the W3C standard to retrieve information from XML documents. Moreover, graphical user interfaces are user friendly enough for naive users to use them. Thus, a graphical query language for XML documents is a very interesting research field. In this paper we introduce KINISIS a new graphical query language which is designed and implemented upon XQuery which uses metaphors extracted from the road traffic act. Moreover, we present the results of the controlledexperiment that we developed in order to evaluate KINISIS usability against XQuery.
The user's view level of the GOQL graphical query language
Abstract The paper addresses issues related to the design of a graphical query mechanism that can... more Abstract The paper addresses issues related to the design of a graphical query mechanism that can act as an interface to any Object-Oriented Data Base System (OODBS), in general, and the Object Model of ODMG 2.0, in particular. In the paper, a brief literature survey of related ...
The Graphical Object Query Language (GOQL) is a graphical query language that complies with the O... more The Graphical Object Query Language (GOQL) is a graphical query language that complies with the ODMG 3.0 standard and runs on top of the o2 DBMS. GOQL provides users with the User's View (UV) and the Folders Window (FW), which serve as the foundation upon which end-users pose ad-hoc queries. The UV is a graphical representation of any underlying ODMG scheme. Among its advantages is that it hides from end-users most of the perplexing details of the object-oriented database model, such as methods, hierarchies and relationships. To achieve this, the UV does not distinguish between methods, attributes and relationships, it encapsulates is-a hierarchies and it utilises a number of desktop metaphors whose semantics can be easily understood by end-users. The FW is a condensed version of the UV and provides the starting point for constructing queries. In this paper, we demonstrate the UV and the FW and discuss GOQL's system architecture, its various components and the way these components interact to generate the UV and the FW and to provide an ad hoc query construction mechanism.
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Language (GOQL). The UV provides a graphical representation for object-oriented database schemas ... more Language (GOQL). The UV provides a graphical representation for object-oriented database schemas and hides from end-users most of the perplexing details of the object-oriented database model, such as methods, hierarchies and relationships. In particular, the UV does not distinguish between methods, attributes and relationships, encapsulates the is-a hierarchy and utilises a number of desktop metaphors to present a graphical schema that is easy to be understood by end-users. Thus, the UV provides the environment, through which endusers, can pose ad-hoc queries through GOQL.
The Student Module of ReProTool – Allowing Student Input in ECTS Re-Engineering of University Programmes
International Journal of Web Engineering and Technology, 2013
The study presented in this paper is a controlled experiment, aiming at investigating the underst... more The study presented in this paper is a controlled experiment, aiming at investigating the understandability and correctness in two query languages, namely KINISIS against XQuery. XQuery is the W3C standard query language for XML documents. KINISIS is a graphical query language which is designed and implemented upon XQuery, using metaphors extracted from the European Road Traffic Act. We conducted a controlled experiment in order to assess users' performance, with respect to understanding and correctness, in developing queries in KINISIS and in XQuery. The findings, from the collected and statistically analysed data, showed that users performing on KINISIS had significantly better results comparing to those using XQuery. As an output of this study, is that a graphical XQuery language that is based on successful metaphors is more appropriate for novice users in XQuery technology, instead of textual XQuery.
During the last two decades, information has been stored in a plethora of different databases, lo... more During the last two decades, information has been stored in a plethora of different databases, locations and data models. In many cases, companies and organizations use data, that is stored in a variety of data models and remote database servers, which can be correlated. A challenge would be to define queries joining data from all those different sources. Thus, data can be found in Relational, Object-Relational, Object-Oriented, XML databases or even in text files. For each model there is a corresponding query language, i.e. SQL, SQL3, OQL and XQuery. Moreover, it is very tricky to join data from different sources and we have not found in the literature a query language that has been designed to use data in the same query from Relational, Object-Relational, Object-Oriented and XML databases.
the 6th WSEAS International …, 2002
In this paper we present a comparison analysis of the most important graphical models of objector... more In this paper we present a comparison analysis of the most important graphical models of objectoriented databases. These models are also compared with the graphical model (User's View -UV) of GOQLour graphical query language for object-oriented databases. The comparison is based on an example of an object-oriented database schema whose graphical representation is given in the most important graphical models that exist in the literature -including GOQL. The comparison illustrates the limitations of these models as compared with the UV of GOQL.
The GOQL graphical query language
International journal of …, 2002
The authors present a graphical query language, GOQL (Graphical Object Query Language), for objec... more The authors present a graphical query language, GOQL (Graphical Object Query Language), for object-oriented data base systems, in general, and the object model of ODMG 2.0, in particular. A detailed literature survey of related work is given, and an analysis ...
HERMES: A Tool for Querying Heterogeneous Data Stores
2012 16th Panhellenic Conference on Informatics, 2012
ABSTRACT Data are organized/stored in a plethora of different databases, locations and data model... more ABSTRACT Data are organized/stored in a plethora of different databases, locations and data models. In many cases, companies and organizations utilize data stored in a variety of data models at remote database servers. A challenge would be to construct queries that join data from such disparate sources. In this paper, we report on research work relating to graphical query languages and data modeling. More specifically, we report on a new software tool for the novice user, one that transforms databases of different data models (Relational, Object-Relational, Object-Oriented) into an equivalent XML model, plus on a new graphical XQuery type query language that facilitates the construction of user queries that join data from different data models.
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Papers by Euclid Keramopoulos