GeoCouch: A spatial index for CouchDB - FOSS4G2010.foss4g.org/presentations/3048.pdf ·...

Intro CouchDB GeoCouch GeoCouch:A spatial index for CouchDB

GeoCouch:

A spatial index for CouchDB

Volker Mische

Free and Open Source Software for GeospatialSeptember 6–9th 2010

Barcelona

Volker Mische FOSS4G 2010 Barcelona 1 / 33


What is GeoCouch?

A spatial index for CouchDB



?Volker Mische FOSS4G 2010 Barcelona 3 / 33


NoSQL



Documents

{"_id": "Station-2942_001","_rev": "3-77f17a55f6ab11f7f6668e63a75f2281",

"name": "Station-2942","date": "2010-09-09","loc": [2.183333, 41.383333],"country": "Spain","temperature": 25,"rainfall": 3

}



RESTful HTTP API

The four basic functions of a database (CRUD):

Create HTTP PUT /db/Station-2942_001

Read HTTP GET /db/Station-2942_001

Update HTTP PUT /db/Station-2942_001

Delete HTTP DELETE /db/Station-2942_001



Fancy Features



Schema free



Arbitrary input/output

JSON + JavaScript=

anything



Concurrency/Robustness

No lock on reads (MVCC)

Append-only

Durability (crash-only design)



Replication



GeoCouch



Previous version

CouchDB Python

SpatiaLite

HTTP Request stdin/out

HTTP Response

GeoCouch



Current version

CouchDBHTTP Request

HTTP Response GeoCouch



GeoCouch Features



GeometryCollection

Polygon

MultiPolygonMultiLineString

MultiPoint

Point

LineString

XXX OpenSeaarchVolker Mische FOSS4G 2010 Barcelona 16 / 33


Barcelona

La Barceloneta

Palau Reial

Pius XII

Maria Cristina

Avinguda de Xile

Zona Universitària

Ernest Lluch

Prat de la Riba

Ildefons Cerdà

Europa-Fira

Fira

Parc Logistic

Zona Franca Port

Foc Cisell

Foneria

Bellvitge

Can Rigal

Campus Nord

Campus Sud

Manel Girona

Provençana

Torrassa

Gornal

Collblanc

Marina

Zona Franca Litoral

Motors

Plaça del Centre

Plaça de Sants

L'Illa

Mercat Nou

Les Corts

Numancia

Santa Eulàlia

Badal

Bellvitge

Sant Josep

Pubilla Cases

Florida

Rocafort

Espanya

Hospital Clínic

Entença

Tarragona

Francesc Macià

Passeig de Gràcia

Sant Antoni

Universitat

Barcelona - Passeig de Gràcia

Poble Sec

Urgell

Magòria-La Campana

Sants Estació

Tetuan

Drassanes

Liceu

Barcelona - Plaça Catalunya

Paral·lel

Girona

Barcelona - Arc de Triomf

Ciutadella - Vila Olímpica

Bogatell

Wellington

Arc de Triomf

Hostafrancs

Barceloneta

Urquinaona

Jaume I Estació de França

senalataC stroC sel ed aiV narG

airàcI 'd adinevA

Passeig de Gràcia

anat

eiaL

a

iV

lanogaiD .va

àirraS ed adugnivA

B-10

Carrer d

e Ber

lin

Gran Via

de les C

orts

Cat

alan

es

Pass

eig

de C

olom

B-10

Carrer N

umancia

amoR ed adugnivA

giM l

ed

ad

no

R

Ronda d

el M

ig

Trav

esse

ra de le

s Cor

ts

Avingu

da de Madrid

giM led adnoR

Carrer de Sants

alaz

irA'

d rer

raC

stroC sel ed aressevarT

tlaD ed adno

R

B-20

B-20

ógarA

B-20

redaugiA rotcoD led rerraC

lanogaiD .va

av. Diagonal

lanogaiD adugnivA

Avinguda Diagonal

Avinguda del Paral·lellel·laraP led adugnivA

L'Hospitaletde Llobregat

Antiguocircuito

de Montjuic

TERCAT

Cementiride Montjuïc

Parcdel migdia

Parcde La

Ciutadella

JardíBotànic

de BarcelonaVolker Mische FOSS4G 2010 Barcelona 17 / 33


Count



List function(arbitrary output)



R-Tree vs. Geohash

R-Tree Geohash

Data Structure R-Tree B-Tree

Approximation bounding box point

BBox precision exact approximate

Good for all geometries points

Used by PostGIS,SpatiaLite, Oracle

Spatial

MongoDB



Benchmarks



Benchmarks: Competitors

PostGIS 1.4.0

SpatiaLite 2.4.0RC2

GeoCouch tag: diplomathesis



Benchmarks: Datasets

100 000 points

USGS GNIS

350 000 polygons

TIGER



Benchmarks: Test 1

50%Volker Mische FOSS4G 2010 Barcelona 24 / 33


50 000 75 000 100 000 125 000 150 000 175 000Number of returned polygons

0

500

1000

1500

Tim

e in

mill

isec

onds

Bounding box query returning approx. 50% of the polygons

PostGIS 1.4.0SpatiaLite 2.4.0GeoCouch tag: diplomathesis



20 000 30 000 40 000 50 000Number of returned points

0

100

200

300

400

500

Tim

e in

mill

isec

onds

Bounding box query returning approx. 50% of the points




Benchmarks: Test 2

25%20%

15%10%

5%



17 500 35 000 52 500 70 000 87 500Number of returned polygons

0

500

1000

1500

2000Ti

me

in m

illis

econ

ds

Query with changing bounding box sizes(350 000 polygons)




5 000 10 000 15 000 20 000 25 000Number of returned points

0

50

100

150

200

250

300

350

400

Tiem

in m

illis

econ

ds

Query with changing bounding box sizes(100 000 points)




Applications



http://pdxapi.com/



Next steps

Polygon search (→ Erlang geometry library)

Sharding

Layer on top (e.g. for clustering, reprojection)



Thanks!



Get in touch with me

Webiste: http://vmx.cx/

IRC: vmx @ freenode

Email: [email protected]

Jabber: [email protected]


GeoCouch: A spatial index for CouchDB - FOSS4G2010.foss4g.org/presentations/3048.pdf ·...

Documents

Transcript of GeoCouch: A spatial index for CouchDB - FOSS4G2010.foss4g.org/presentations/3048.pdf ·...