technical solution that could increase geo-spatial data legal compliance, currency, accuracy, and efficiency of updates as well as address system scaling for performance

1. Kalyan K. Janakiraman
Land and Property Information / Macquarie University
kalyankj@gmail.com
Prof. Mehmet A Orgun
Department of Computing
Macquarie University, NSW
mehmet@comp.mq.edu.au
Dr. Abhaya Nayak
Department of Computing
Macquarie University, NSW
Abhaya@comp.mq.edu.au

2. Relevance
Geospatial Applications are becoming main
stream decision support Systems
Growing demand for accurate current geographic
information in critical sectors
Expensive and difficult to update and maintain
To explore for technical solution that could increase geo-spatial
data legal compliance, currency, accuracy, and efficiency of
updates as well as address system scalability
Objective:

3. LPI’sSpatialInformationExchange(SIX)portal
http://lite.maps.nsw.gov.au/
Tries to provide
current
information for
business and
Government of
NSW

4. DataandJurisdictionalDomains
NSW Land & Property Authority (LPI)
- Cadastral Lots feature class
- Address points feature class
- Elevation contours feature class
RTA / Dept of transport
- Road centre lines
- Road Corridors
- Roads under repair/restricted
-Traffic signals, operations, Bus routes
County / Dept of Planning
- Land-use Planning zones
-Planning height control/FSR restrictions
County / local Government Authority
- Suburbs boundaries
- State/Federal electoral boundaries
- LGA Boundaries
Data that makeup what we see is from many data layers and is distributed vertically
among many government agencies and horizontally among many different administrative
domains.

5. GeographicData–Transactionalperspective
• Typically, many DBMS transactions per geospatial
transactionLarge Atomicity:
• commonly takes many days to prepare and commit one
geospatial transaction
Multi-session,
Multi-user, long
transaction
• Direct – no concern for geospatial integrity
• Versioned– commonly used in most production
environments. 4 states: create version, edit, fix
conflicts (reconcile) and commit (Post)
• Local session -- OpenStreetMap uses
Versioned
Updating

6. GeospatialTransactionexample
A case of a release of a portion of forest-land for residential development.
Managed by State Forest Authority
Managed by LPI
Managed by Dept of Transport
To update consistently, 3 layers held by 3
departments needs to be modified as a
single geospatial transaction.
Version beginning:
Changes to State Forest Layer
Changes to Cadastral Layer
Changes toTransport Layer
Version end

7. GeographicTransactionsinNSW–2month
snapshotfromLPI
▪ 7756 geospatial transactions were recorded in LPI comprising 60 layers.
▪ One layer geospatial transaction: Only111occurrences
▪ Average: 9 layers, 118 changes per geospatial transaction.
▪ Maximum: 40 layers per geospatial transaction
▪ About 25% of edits (230,000 edits) - other agency data (unauthorized / redundant).
0
500
1000
1500
2000
2500
3000
3500
1
2to9
10-19
20-29
30-39
40-49
50-59
60-69
70-79
80-89
90-99
100-109
110-119
120-129
130-139
140-149
150-159
160-169
170-179
180-189
190-199
200-209
210-219
220-229
230-239
240-249
250-259
260-269
270-279
280-289
290-299
300+
Frequency
database transactions per geospatial transaction

8. LPI
State Forest Department
PresentUpdatingWorkflow(Silo)
Create
Version
Edit Reconcile Post
Dept of Transport
Each Agency is a silo. Each may be doing the same unaware of the other
agency’s activity

9. Serialized geospatial transaction distribution
▪ Each geospatial transaction captured and applied to other repositories serially
▪ Serializability property does not hold. Each geospatial transaction need to be
applied in the same order as they occurred in the source repository.
PostedVersion
PostedVersion
PostedVersion
Tn
Agent Handler
Posted
VersionPosted
VersionPosted
Version Tn-3
http-soap/
MQ/ftp transport
Time
Node1 Node2
Janakiraman, K. K; Hansen, L, Orgun, M; "Failed-tuple blocking strategy for near-real time geospatial database
replication," Proceedings of the First conference on Computing for Geospatial Research & Application InternationalConference
on , vol., no., pp.__, 21-23 June 2010.
Failure handling:

10. LPI
Versionedfederatedgeo-databaseworkflow
State Forest Dept
Create
Version
Edit Reconcile Request
Post
Dept ofTransport
Verify /
Change
Verify /
Change
Accept
Post
Accept
Post
Accept
Post

11. State Forest Dept
LPI
VersionedFederatedgeo-database(Crowdsourced)
Create
Version
Edit Reconcile Request Post
Dept of Transport
Verify / Change Accept
Post
Accept
Post
Accept
Post
{Public residents}
Verify /
Change
Accept
Post
Verify / Change

12. Geo-database scaling:
PostedVersion
PostedVersion
PostedVersion
Tn
Agent Handler
http-soap/
MQ/ftp transport
Time
Node-1
Node-2 Node…
Node-n
Handler
Handler
Handler-n
- Node synchronisation by serialised geospatial transaction propagation
- Will be accurate to last but one Committed geospatial transaction
replicated.

13. Lot
Boundary
WS
Cloudgeo-databaseDataaccessarchitecture
Roads
Centreline
WS
REST Style
Web-services (one for each layer)
Forest
Boundary
WS
Version
Controller
WS
Get
Get
Get
Create/
Reconcile/
RequestPost
Put/
post/
deleteCharacteristics:
• Data access only through web-services
• WS stateless
• WS rapidly scalable
• WS simple and pure REST style
Notification feed
Queue

14. @Entity
@Table(name = “suburb")
public class Suburb {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name = "gid")
private Long id;
@Column(name = "name")
private String name;
@Column(name = "the_geom")
@Type(type =
"org.hibernatespatial.GeometryUserType")
private MultiPolygon geometry;
public MultiPolygon getPolygon() {
return geometry;
}
}
GET
Envelope box = //Window rectangle;
List<RLSuburb> stnList = (List<RLSuburb>)RLSuburbDao.get(box);
for (RLSuburb event : stnList) {
System.out.println(event);
}
GET OPERATION – EXAMPLE FOR SUBURB LAYER
Output:
MULTIPOLYGON (((30 20, 10 40, 45 40, 30 20)),…))
…

15. Cloudgeo-database:Versionmanagement
Version_id Version_name
Version_id layer Feature_id timestamp Owner_decision timestamp
Unique
ActiveVersions
Active changes
Version
Post Background
Agent
Commit is initiated when OWNER_DECISION
For all the changed feature for a version = POST
{RequestPost, notified, Reject, Post}

16. OverallCloudGeo-databaseArchitecture
▪ Cloud as a Database Service – agencies subscribe.
▪ one unique URL per geospatial Layer.
▪ Write access to custodian Agency.
▪ Read access to all subscribing agency.
▪ versioning managed by cloud.
▪ Any layer can participate in versioned updating.
▪ Non-authorised updates would propagate to the responsible
authority for consideration for update.
▪ Scaling through node synchronisation by serialised geospatial
transaction propagation.
▪ Authentication/Access control for agency+user combination