, Volume 97, Issue 12, pp 1141–1164 | Cite as

An interactive SQL relational interface for querying main-memory data structures

  • Marios FragkoulisEmail author
  • Diomidis Spinellis
  • Panos Louridas


Query formalisms and facilities have received significant attention in the past decades resulting in the development of query languages with varying characteristics; many of them resemble sql. Query facilities typically ship as part of database management systems or, sometimes, bundled with programming languages. For applications written in imperative programming languages, database management systems impose an expensive model transformation. In-memory data structures can represent sophisticated relationships in a manner that is efficient in terms of storage and processing overhead, but most general purpose programming languages lack an interpreter and/or an expressive query language for manipulating interactive queries. Issuing interactive ad-hoc queries on program data structures is tough. This work presents a method and an implementation for representing an application’s arbitrary imperative programming data model as a queryable relational one. The Pico COllections Query Library (pico ql) uses a domain specific language to define a relational representation of application data structures and an sql interface implementation. Queries are issued interactively and are type safe. We demonstrate our relational representation for objects and the library’s usefulness on three large c++ projects. pico ql enhances query expressiveness and boosts productivity compared to querying via traditional programming constructs.


sql Interactive Query Main-memory  Object 

Mathematics Subject Classification




The authors would like to thank Georgios Gousios, Damianos Chatziantoniou, and Yannis Smaragdakis for their comments on earlier drafts of this paper. This work was funded by Foundation Propondis.


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Copyright information

© Springer-Verlag Wien 2015

Authors and Affiliations

  1. 1.Department of Management Science and TechnologyAthens University of Economics and BusinessAthensGreece

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