This document describes an RDF saturation algorithm implemented in Java within the RDFVS project. The saturation algorithm is responsible for finding and storing implicit RDF triples by reasoning over input RDF data and RDFS schema. It uses PostgreSQL for data storage and supports updating the saturated triples when new data or schema information is received. The algorithm has been implemented as modules with over 6,000 lines of code by a single contributor.

1. RDF
satura*on
algorithm
based
on
Postgres
Owner
:
Alexandra
ROATIS
Presenter
:
Stama*s
ZAMPETAKIS
2%

2. RDF
Satura*on
algorithms
• Overview:
The
saturator
is
responsible
for
finding
and
storing
implicit
RDF
instance
triples
for
the
RDF
data
and
the
RDFS
schema
that
were
given
as
an
input.
It
also
supports
smart
updates
when
new
data/
new
schema
informaAon
arrives.
• SVN
LocaAon:
hEps://scm.gforge.inria.fr/svn/distriples/trunk/Sat-­‐vs-­‐Ref
• Code
specificaAons:
• It
is
implemented
inside
RDFVS
project
• Lines
of
code:
6016
• Types:
18
• Language:
JAVA
• Contributors:
Alexandra
RoaAs
• Current
Users:
None
2

3. Modules
3
Conjunctive
Query Result User preferences
SAT Manager Schema Manager
RDF Data
Query Manager
Update Manager
Data Loader
RDF Schema
S P O K V S P O S P O C I
Postgres
Data
Table
Dictionary
Table
Saturated
Table
ExtSaturated
Table

4. Modules
4
Conjunctive
Query Result User preferences
SAT Manager Schema Manager
RDF Data
Query Manager
Update Manager
Data Loader
RDF Schema
S P O K V S P O S P O C I
Postgres
Data
Table
Dictionary
Table
Saturated
Table
ExtSaturated
Table
Holds how many times
this tuple is inferred
A boolean value that is
showing if this is an
inferred tuple or not

5. Satura*on
Algorithms
5
DirectSaturation
S P O K V
S P O S P O I1 I2
Saturated
Table
ExtSaturated
Table
Data
Table
Dictionary
Table
Distributed
Saturation
DictDistributed
Saturation
DictTruthMaint
Saturation
TruthMaint
Saturation
SAT Module
INPUT ALGORITHM OUTPUT
<Partition size>

6. Technical
Dependencies
–
TODOS
• Dependencies:
• Postgres
• Jena
• Log4j-­‐logger
• TODO:
Separate
saturaAon
algorithms
from
RDFVS
project
• Known
bugs:
none
6

7. Related
Publica*ons
• François
Goasdoué,
Ioana
Manolescu,
Alexandra
RoaAs:
Efficient
query
answering
against
dynamic
RDF
databases.
EDBT
2013
7

8. Merci
8