#gStoreD
gStoreD is a distributed RDF data management system (or what is commonly called a "triple store") that is based on "partial evaluation" and maintains the graph structure of the original RDF data. Its data model is a labeled, directed multiedge graph, where each vertex corresponds to a subject or an object. We also represent a given SPARQL query by a query graph Q. Query processing involves finding subgraph matches of Q over the RDF graph G.
System Requirement: 64-bit linux server with GCC, mpich-3.0.4, make, readline installed. We have tested on linux server with CentOS 6.2 x86_64. The version of GCC should be 4.4.7 or later.
You can install gStore v0.3.0-D in one command. Just run
# make
to compile the gStore code and build executable "gloadD", "gqueryD".
gStore v0.3.0-D currently includes four executables and others.
####1. gloadD gloadD is used to build a new database from a RDF triple format file.
# mpiexec -f host_file_name -n host_number + 1 ./gloadD db_name rdf_triple_file_name internal_vertices_file_name
The host file is used to idenitfy the hosts. "host_number + 1" means that there should be one more process as the master site.
Each line in the file of the internal vertices consists of two parts: the first part is the URI of an resouce, and the second part is the identifier of the partition that the resouce belongs to. The tab "\t" is used as the separator.
For example, we build a database from dbpedia_example_distgStore.n3 which can be found in example folder.
[root@master Gstore]# mpiexec -f hosts.txt -n 5 bin/gloadD db_dbpedia_example_distgStore ./example/dbpedia_example_distgStore.n3 ./example/dbpedia_example_distgStore_internal.TXT
####2. gqueryD gqueryD is used to query an exsisting database with SPARQL files.
mpiexec -f host_file_name -n host_number + 1 ./gqueryD db_name query_file_name
When the program finish answering the query, the SPARQL matches are written in the file named finalRes.txt.
gStorev0.3.0-D only support simple "select" queries and "ask" queries of BGP now, and all variables occuring in the "where" clause of a "select" query should also occur in the "selsect" clause.
We also take dbpedia_example_distgStore.n3 as an example.
[root@master Gstore]# mpiexec -f hosts.txt -n 5 bin/gqueryD db_dbpedia_example_distgStore ./example/query.txt
Notice:
All results are output into finalRes.txt.
If you encounter any problems, please send emails to me (email address: hnu16pp@hnu.edu.cn).