Talk given at Smart Data 2017 Relational Databases are inflexible due to the rigid constraints of the relational data model. If you have new data that doesn’t fit your schema, you will need to alter your schema (add a column or a new table). This is a task that is not always possible. IT departments don't have time, or they won't allow it - just more nulls that can lead to query performance degradation, etc. A goal of graph databases is to address this problem with their schema-less graph data model. However, many businesses have large investments in commercial RDBMSs and their associated applications and can't expect to move all of their data to a graph database. In this talk, I will present a multi-model graph/relational architecture solution. Keep your relational data where it is, virtualize it as a graph, and then connect it with additional data stored in a graph database. This way, both graph and relational technologies can seamlessly interact together.

1. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Virtualizing Relational Databases as
Graphs: a multi-model approach
Juan F. Sequeda, Ph.D
Co-Founder
Capsenta
1
(i.e. Want Graphs? Have Relational? No Problem!)
Smart
Data/Graphorum Conference
– February
1,
2017

2. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Background
• Ph.D.
from
UT
Austin
Computer
Science
• Research
on
Integrating
Relational
Databases
with
Semantics
and
Graphs
• Editor
W3C
Standard
on
Mapping
Relational
Databases
to
Graphs
• Co-­‐Founder
Capsenta,
spinout
from
UTCS
2

3. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Takeaway
• Relational
Databases
can
be
virtualized
as
Graphs!
• Do
you
really
need
to
create
another
database?
3

4. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com 4

5. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Graphs
are
Cool!
5

6. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Flexible
6
:US_Constitution_1992/
section/123
“Excessive
bail
shall
not
be
required,
nor
excessive
fines
imposed,
nor
cruel
and
unusual
punishments
inflicted.”
:text
:US_Constitution_1992
“United
States
of
America
1789
(rev.
1992)”
:text
:isSectionOf
:Cruelty
:hasTopic
“Prohibition
of
cruel
or
degrading
treatment”
:label
“inhumane
treatment”
:keyword

7. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Integration
7
:US_Constitution_1992/
section/123
“Excessive
bail
shall
not
be
required,
nor
excessive
fines
imposed,
nor
cruel
and
unusual
punishments
inflicted.”
:text
:US_Constitution_1992
“United
States
of
America
1789
(rev.
1992)”
:isSectionOf
:Cruelty
:hasTopic
“Prohibition
of
cruel
or
degrading
treatment”
:label
“inhumane
treatment”
:keyword
:text
:EighthAmendment_US
Constitution
:Farmer_vs_Brennan
:lawsApplied
“A
prison
official’s
‘deliberate
indifference’
to
a
substantial
risk
of
a
serious
harm
to
an
inmate
violates
the
Eighth
Amendment”
:holding
:sameAs
:Prisons_in
_Indiana
:LGBT_right
_case_laws
:subject
:subject

8. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Data
and
Metadata
are
One
8
:US_Constitution_1992/
section/123
“Excessive
bail
shall
not
be
required,
nor
excessive
fines
imposed,
nor
cruel
and
unusual
punishments
inflicted.”
:text
:US_Constitution_1992
“United
States
of
America
1789
(rev.
1992)”
:isSectionOf
:Cruelty
:hasTopic
“Prohibition
of
cruel
or
degrading
treatment”
:label
“inhumane
treatment”
:keyword
:text
:Section :Constitution:Topic
:Rights
_and_
Duties
:Physical
_Integrity
_Rights
:subClass
:subClass
:subClass
:hasTopic :isSectionOf
:type
:type

9. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Common
denominator
9
<constitution id=“US_Constitution_1992”>
<section id="US_Constitution_1992/section/123">
<text>Excessive bail shall ...</text>
</section>
<topic>Cruelty</topic>
</constitution>
“Excessive
bail
shall
not
be
required,
nor
excessive
fines
imposed,
nor
cruel and
unusual
punishments
inflicted.”
id text topic
123 Excessive
bail
shall…
Cruelty
:US_Constitution_1992/
section/123
“Excessive
bail
shall
not
be
required,
nor
excessive
fines
imposed,
nor
cruel
and
unusual
punishments
inflicted.”
:text
:Cruelty
:hasTopic
XML Text
Tabular

10. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Traversal,
Navigation,
Reachability
10
:US_Constitution_1992/
section/123
“Excessive
bail
shall
not
be
required,
nor
excessive
fines
imposed,
nor
cruel
and
unusual
punishments
inflicted.”
:text
:US_Constitution_1992
“United
States
of
America
1789
(rev.
1992)”
:isSectionOf
:Cruelty
:hasTopic
“Prohibition
of
cruel
or
degrading
treatment”
:label
“inhumane
treatment”
:keyword
:text
:EighthAmendment_US
Constitution
:Farmer_vs_Brennan
:lawsApplied
“A
prison
official’s
‘deliberate
indifference’
to
a
substantial
risk
of
a
serious
harm
to
an
inmate
violates
the
Eighth
Amendment”
:holding
:sameAs
:Prisons_in
_Indiana
:LGBT_right
_case_laws
:subject
:subject

11. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Semantics
11
:US_Constitution_1992/
section/123
“Excessive
bail
shall
not
be
required,
nor
excessive
fines
imposed,
nor
cruel
and
unusual
punishments
inflicted.”
:text
:Cruelty
:hasTopic
“Prohibition
of
cruel
or
degrading
treatment”
:label
“inhumane
treatment”
:keyword
:Physical
_Integrity
_Rights
:subClass
:hasTopic

12. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
(Summary)
Why
are
Graphs
Cool?
12
• Flexible
• Integration
• Data
and
Metadata
are
one
• Common
Denominator
• Traversal,
Navigation,
Reachability
• Semantics
ACM
Computing
Surveys
2008

13. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Are
Relational
Databases
cool?
13

14. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Flexible
14
id attr1 attr2 attr3 attr4 … attrn …
id attribute value
id attr1 val1 attr2 val2 attr3 val3
id value
attr1
id value
attr2
id value
attr3
Copeland
and
Khoshafian.
A
decomposition
storage
model.
SIGMOD
1985
Agrawal
et
al.
Storage
and
Querying
of
E-­‐Commerce
Data.
VLDB
2001

15. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Integration
15
Extract
Transform
Load

16. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Data
and
Metadata
are
One
16
CREATE TABLE Person (
id int primary key,
Name varchar not null,
…
)
Company closePrice closeDate
IBM 130 1/15/2016
MSFT 50.99 1/15/2016
IBM MSFT closeDate
130 50.99 1/15/2016
closePrice closeDate
130 1/15/2016
closePrice closeDate
50.99 1/15/2016
IBM MSFT
-­‐ Krishnamurthy
et
al.
Language
features
for
interoperability
of
databases
with
schematic
discrepancies.
SIGMOD
1991
-­‐ Lakshmanan et
al.
SchemaSQL -­‐ A
Language
for
Interoperability
in
Relational
Multi-­‐database
Systems.
VLDB
1996

17. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Common
denominator
• Social
Network
• Hierarchical
Data
17

18. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Traversal,
Navigation,
Reachability
• Write
a
bunch
of
Joins
• Recursion
18

19. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Semantics
• Views
• Triggers
19

20. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
(Summary)
Are
Relational
Databases
Cool?
• Flexible
• Integration
• Data
and
Metadata
are
one
• Common
Denominator
• Traversal,
Navigation,
Reachability
• Semantics
20

21. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Ditch
your
Relational
Database
and
move
to
Graphs!?
Feasible?
21

22. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Query
Federation
What
if
…
22
Virtualize
Relational
Databases
as
Graphs
Keep
your
legacy
data
in
the
RDBMS
Run
graph
queries
over
the
virtual
graph
data
Add
new
data
that
doesn’t
fit
into
the
schema
into
a
separate
graph
Federate
queries
over
Virtualized
Graph
and
the
Real
Graph

23. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Query
Federation
What
if
…
23

24. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
What
type
of
graphs
are
we
talking
about?
24

25. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Property
Graphs
vs
RDF
Graphs
25
:Bob :Alice
foaf:knows
“Bob
Smith”
foaf:name
“Alice
Smith”
foaf:name
id1 id2
knowskey value
name Bob
Smith
key value
name Alice
Smith
key value
since 2005
:g1
2005
:since
http://db-­‐engines.com/en/ranking/graph+dbms http://db-­‐engines.com/en/ranking/rdf+store

26. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
RDF:
Resource
Description
Framework
• Graph
Data
Model
• Subject
(Node)
– Predicate
(Edge)
– Object
(Node)
• W3C
Standard
for
data
on
the
web
• URIs
26
:US_Constitution_1992/
section/123
:US_Constitution_1992
“United
States
of
America
1789
(rev.
1992)”
:isSectionOf
:text

27. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Schemas,
Taxonomies,
Ontologies
27
:Cruelty
:Section :Constitution:Topic
:Rights
_and_
Duties
:Physical
_Integrity
_Rights
:subClass
:subClass
:subClass
:hasTopic :isSectionOf

28. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
SELECT ?x ?title
WHERE{
?x :hasTopic :cruelty.
?x :text ?t
}
SPARQL
Graph
RDF
Graph
:USConst/146
:cruelty
:prerel
“Excesses
bail
shall
not
be
required
…
“
:text
?x :cruelty
:hasTopic
?text
SPARQL
Protocol
and
RDF
Query
Language
28
SPARQL
is
a
Query
Language
• Graph
query
language
for
RDF
• Match
SPARQL
graph
with
RDF
graph
• Much
more
features
in
SPARQL
1.1:
Property
Paths
SPARQL
is
a
Protocol
• Send
query
over
HTTP
GET
or
POST
• Response
to
a
query
is
either
in
XML,
JSON
or
CSV
format
:text

29. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
SPARQL
Graph
RDF
Graph
:USConst/146
:cruelty
:prerel
“Excesses
bail
shall
not
be
required
…
“
:text
?x :cruelty
:hasTopic
?text
:text
SPARQL
Protocol
and
RDF
Query
Language
29
?x ?text
:USConst/146 “Excesses
bail
shall
not
be
required
…
“
SELECT ?x ?title
WHERE{
?x :hasTopic :cruelty.
?x :text ?t
}

30. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Virtualizing
Relational
Databases
as
Graphs
30

31. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Relational
Database
to
RDF
(RDB2RDF)
31
ID NAME AGE CID
1 Alice 25 100
2 Bob NULL 100
Person
CID NAME
100 Austin
200 Madrid
City
<Person/1>
<City/100>
Alice
25
Austin
<Person/2>
Bob
<City/200> Madrid
foaf:namefoaf:name foaf:age
rdfs:label
rdfs:label
foaf:based_near
Mapping

32. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
W3C
RDB2RDF
Standards
• W3C
Standards
to
map
Relational
Data
to
RDF
• A
Direct
Mapping
of
Relational
Data
to
RDF
– Default
automatic
mapping
of
relational
data
to
RDF
• R2RML:
RDB
to
RDF
Mapping
Language
– Customizable
language
to
map
relational
data
to
RDF
32

33. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
RDF
W3C
Direct
Mapping
33
Relational
Database
Direct
Mapping
Engine
Input:
Database
(Schema
and
Data)
Primary
Keys
Foreign
Keys
Output
RDF
graph
https://www.w3.org/TR/rdb-­‐direct-­‐mapping/

34. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
W3C
Direct
Mapping
Result
34
ID NAME AGE CID
1 Alice 25 100
2 Bob NULL 100
Person
CID NAME
100 Austin
200 Madrid
City
<Person/ID=1>
<City/CID=100>
Alice
25
Austin
<Person/ID=2>
Bob
<City/CID=200> Madrid
Person#Name Person#Age
City#Name
City#Name
Person#ref-­‐CID
Direct
Mapping
Person#Name

35. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
R2RML
35
R2RML
Engine
R2RML
File
:Cruelty
:Section :Constitution:Topic
:Rights
_and_
Duties
:Physical
_Integrity
_Rights
:subClass:subClass
:subClass
:hasTopic :isSectionOf
RDF
Relational
Database
Target
Schema
https://www.w3.org/TR/r2rml/

36. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
<TriplesMap1>
a rr:TriplesMap;
rr:logicalTable [ rr:tableName”Person" ];
rr:subjectMap [ rr:template
"http://www.ex.com/Person/{ID}";
rr:class
foaf:Person ];
rr:predicateObjectMap [
rr:predicate foaf:based_near ;
rr:objectMap [
rr:parentTripelMap <TripleMap2>;
rr:joinCondition [
rr:child “CID”;
rr:parent “CID”;
]
]
]
.
<TriplesMap2>
a rr:TriplesMap;
rr:logicalTable [ rr:tableName ”City" ];
rr:subjectMap [ rr:template "http://ex.com/City/{CID}";
rr:class ex:City ];
rr:predicateObjectMap [
rr:predicate foaf:name;
rr:objectMap [ rr:column ”TITLE" ]
]
.
Example
R2RML
36

37. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Graph
Data
Virtualization
37
SPARQL
RDBMS Graph
SQL
SQL
Results
SPARQL
Results
R2RML
Mapping
by

38. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Performance
of
Ultrawrap
• Reuse
existing
relational
infrastructure
– 30+
years
of
optimizations
– Semantic
Query
Optimizations
• Result:
SPARQL
as
fast
as
SQL
38
Sequeda
J.
Integrating
Relational
Databases
with
the
Semantic
Web.
IOS
Press.
2016
http://www.iospress.nl/book/integrating-­‐relational-­‐databases-­‐with-­‐the-­‐semantic-­‐web/

39. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Demo
39

40. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Semantic
Data
Virtualization
as
a
Bridge
for
BI
40
HIVE
Impala,
etc
Oracle
SQL
Server
Postgres
Unstructured
Semi-­‐
Structured
Enterprise
Knowledge
Graph
Search ReportsAPI
BI
Connectors
(Tableau,
…)

41. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
Takeaway:
Tipping
Point
41
Relational
Database
Graphs
• Flexible
• Integration
• Data
and
Metadata
are
One
• Common
Denominator
• Traversal,
Navigation,
Reachability
• Semantics
Do
you
really
need
another
database?
Relational
Databases
can
be
virtualized
as
Graphs

42. Smart Data for Smarter Business | © 2016 Capsenta | capsenta.com
THANK
YOU
Juan
Sequeda,
Ph.D
Co-­‐Founder
– Capsenta
juan@capsenta.com
@juansequeda
42