Authors:
Giuseppe Psaila
1
;
Stefania Marrara
2
and
Paolo Fosci
1
Affiliations:
1
University of Bergamo, DIGIP, Viale Marconi 5, 24044 Dalmine (BG), Italy
;
2
Cefriel, viale Sarca 226, 20126 Milano, Italy
Keyword(s):
GeoJSON Documents, Soft Querying of GeoJSON Documents, Fuzzy J-CO-QL Queries.
Abstract:
GeoJSON documents have become important sources of information over the Web, because they describe geographical information layers. Supposing to have such documents stored in some JSON store, the problem of querying them in a flexible and easy way arises. In this paper, we propose a soft-querying model to easily express queries on features (i.e., data items) within GeoJSON documents, based on linguistic predicates. These are fuzzy predicates that evaluate the membership degree to fuzzy sets; this way, imprecise conditions can be expressed and features can be ranked, accordingly. The paper presents a rewriting technique that translates soft queries on GeoJSON documents into fuzzy J-CO-QL queries: this is the query language of the J-CO Framework, an Internet-based framework able to get, manipulate and save collections of JSON documents in a way totally independent of the source JSON store.