<s>
A	O
spatial	B-Algorithm
database	I-Algorithm
is	O
a	O
general-purpose	O
database	O
(	O
usually	O
a	O
relational	B-Application
database	I-Application
)	O
that	O
has	O
been	O
enhanced	O
to	O
include	O
spatial	B-General_Concept
data	I-General_Concept
that	O
represents	O
objects	O
defined	O
in	O
a	O
geometric	O
space	O
,	O
along	O
with	O
tools	O
for	O
querying	B-Library
and	O
analyzing	O
such	O
data	O
.	O
</s>
<s>
Most	O
spatial	B-Algorithm
databases	I-Algorithm
allow	O
the	O
representation	O
of	O
simple	O
geometric	O
objects	O
such	O
as	O
points	O
,	O
lines	O
and	O
polygons	B-General_Concept
.	O
</s>
<s>
Some	O
spatial	B-Algorithm
databases	I-Algorithm
handle	O
more	O
complex	O
structures	O
such	O
as	O
3D	O
objects	O
,	O
topological	B-General_Concept
coverages	I-General_Concept
,	O
linear	O
networks	O
,	O
and	O
triangulated	B-Algorithm
irregular	I-Algorithm
networks	I-Algorithm
(	O
TINs	O
)	O
.	O
</s>
<s>
While	O
typical	O
databases	B-Application
have	O
developed	O
to	O
manage	O
various	O
numeric	O
and	O
character	O
types	O
of	O
data	O
,	O
such	O
databases	B-Application
require	O
additional	O
functionality	O
to	O
process	O
spatial	B-General_Concept
data	I-General_Concept
types	O
efficiently	O
,	O
and	O
developers	O
have	O
often	O
added	O
geometry	O
or	O
feature	O
data	O
types	O
.	O
</s>
<s>
The	O
Open	O
Geospatial	B-General_Concept
Consortium	O
(	O
OGC	O
)	O
developed	O
the	O
Simple	O
Features	O
specification	O
(	O
first	O
released	O
in	O
1997	O
)	O
and	O
sets	O
standards	O
for	O
adding	O
spatial	O
functionality	O
to	O
database	B-Application
systems	I-Application
.	O
</s>
<s>
The	O
SQL/MM	O
Spatial	O
ISO/IEC	O
standard	O
is	O
a	O
part	O
the	O
SQL/MM	O
multimedia	O
standard	O
and	O
extends	O
the	O
Simple	O
Features	O
standard	O
with	O
data	O
types	O
that	O
support	O
circular	O
interpolations	O
.	O
</s>
<s>
Almost	O
all	O
current	O
relational	O
and	O
object-relational	O
database	B-Application
management	I-Application
systems	I-Application
now	O
have	O
spatial	O
extensions	O
,	O
and	O
some	O
GIS	B-Application
software	I-Application
vendors	O
have	O
developed	O
their	O
own	O
spatial	O
extensions	O
to	O
database	B-Application
management	I-Application
systems	I-Application
.	O
</s>
<s>
Geographic	O
database	O
(	O
or	O
geodatabase	O
)	O
is	O
a	O
georeferenced	O
spatial	B-Algorithm
database	I-Algorithm
,	O
used	O
for	O
storing	O
and	O
manipulating	O
geographic	B-General_Concept
data	I-General_Concept
(	O
or	O
geodata	B-General_Concept
)	O
,	O
i.e.	O
,	O
data	O
associated	O
with	O
a	O
location	O
on	O
Earth	O
.	O
</s>
<s>
The	O
term	O
"	O
geodatabase	O
"	O
may	O
also	O
refer	O
specifically	O
to	O
a	O
set	O
of	O
proprietary	O
spatial	B-Algorithm
database	I-Algorithm
formats	O
,	O
Geodatabase	O
(	O
Esri	O
)	O
.	O
</s>
<s>
The	O
core	O
functionality	O
add	O
by	O
a	O
spatial	O
extension	O
to	O
a	O
database	O
is	O
one	O
or	O
more	O
spatial	O
datatypes	O
,	O
which	O
allow	O
for	O
the	O
storage	O
of	O
spatial	B-General_Concept
data	I-General_Concept
as	O
attribute	O
values	O
in	O
a	O
table	O
.	O
</s>
<s>
Most	O
commonly	O
,	O
a	O
single	O
spatial	O
value	O
would	O
be	O
a	O
geometric	B-Algorithm
primitive	I-Algorithm
(	O
point	O
,	O
line	O
,	O
polygon	B-General_Concept
,	O
etc	O
.	O
)	O
</s>
<s>
The	O
datatypes	O
in	O
most	O
spatial	B-Algorithm
databases	I-Algorithm
are	O
based	O
on	O
the	O
OGC	O
Simple	O
Features	O
specification	O
for	O
representing	O
geometric	B-Algorithm
primitives	I-Algorithm
.	O
</s>
<s>
Some	O
spatial	B-Algorithm
databases	I-Algorithm
also	O
support	O
the	O
storage	O
of	O
raster	B-Algorithm
data	I-Algorithm
.	O
</s>
<s>
Because	O
all	O
geographic	O
locations	O
must	O
be	O
specified	O
according	O
to	O
a	O
spatial	O
reference	O
system	O
,	O
spatial	B-Algorithm
databases	I-Algorithm
must	O
also	O
allow	O
for	O
the	O
tracking	O
and	O
transformation	O
of	O
coordinate	O
systems	O
.	O
</s>
<s>
The	O
second	O
major	O
functionality	O
extension	O
in	O
a	O
spatial	B-Algorithm
database	I-Algorithm
is	O
the	O
addition	O
of	O
spatial	O
capabilities	O
to	O
the	O
query	B-Library
language	O
(	O
e.g.	O
,	O
SQL	B-Language
)	O
;	O
these	O
give	O
the	O
spatial	B-Algorithm
database	I-Algorithm
the	O
same	O
query	B-Library
,	O
analysis	O
,	O
and	O
manipulation	O
operations	O
that	O
are	O
available	O
in	O
traditional	O
GIS	B-Application
software	I-Application
.	O
</s>
<s>
In	O
most	O
relational	B-Application
database	I-Application
management	O
systems	O
,	O
this	O
functionality	O
is	O
implemented	O
as	O
a	O
set	O
of	O
new	O
functions	O
that	O
can	O
be	O
used	O
in	O
SQL	B-Language
SELECT	O
statements	O
.	O
</s>
<s>
Several	O
types	O
of	O
operations	O
are	O
specified	O
by	O
the	O
Open	O
Geospatial	B-General_Concept
Consortium	O
standard	O
:	O
</s>
<s>
Measurement	O
:	O
Computes	O
line	O
length	O
,	O
polygon	B-General_Concept
area	O
,	O
the	O
distance	O
between	O
geometries	O
,	O
etc	O
.	O
</s>
<s>
Predicates	O
:	O
Allows	O
true/false	O
queries	B-Library
about	O
spatial	O
relationships	O
between	O
geometries	O
.	O
</s>
<s>
Examples	O
include	O
"	O
do	O
two	O
polygons	B-General_Concept
overlap	O
?	O
"	O
</s>
<s>
Observer	O
Functions	O
:	O
Queries	B-Library
that	O
return	O
specific	O
information	O
about	O
a	O
feature	O
,	O
such	O
as	O
the	O
location	O
of	O
the	O
center	O
of	O
a	O
circle	O
.	O
</s>
<s>
Some	O
databases	B-Application
support	O
only	O
simplified	O
or	O
modified	O
sets	O
of	O
these	O
operations	O
,	O
especially	O
in	O
cases	O
of	O
NoSQL	B-General_Concept
systems	O
like	O
MongoDB	B-Application
and	O
CouchDB	B-Application
.	O
</s>
<s>
A	O
Spatial	O
index	O
is	O
used	O
by	O
a	O
spatial	B-Algorithm
database	I-Algorithm
to	O
optimize	O
spatial	B-Language
queries	I-Language
.	O
</s>
<s>
Database	B-Application
systems	I-Application
use	O
indices	O
to	O
quickly	O
look	O
up	O
values	O
by	O
sorting	O
data	O
values	O
in	O
a	O
linear	O
(	O
e.g.	O
</s>
<s>
alphabetical	O
)	O
order	O
;	O
however	O
,	O
this	O
way	O
of	O
indexing	O
data	O
is	O
not	O
optimal	O
for	O
spatial	B-Language
queries	I-Language
in	O
two	O
-	O
or	O
three-dimensional	O
space	O
.	O
</s>
<s>
Instead	O
,	O
spatial	B-Algorithm
databases	I-Algorithm
use	O
a	O
spatial	O
index	O
designed	O
specifically	O
for	O
multi-dimensional	O
ordering	O
.	O
</s>
<s>
m-tree	B-Data_Structure
–	O
an	O
m-tree	B-Data_Structure
index	O
can	O
be	O
used	O
for	O
the	O
efficient	O
resolution	O
of	O
similarity	O
queries	B-Library
on	O
complex	O
objects	O
as	O
compared	O
using	O
an	O
arbitrary	O
metric	O
.	O
</s>
<s>
R-tree	B-Library
:	O
Typically	O
the	O
preferred	O
method	O
for	O
indexing	O
spatial	B-General_Concept
data	I-General_Concept
.	O
</s>
<s>
Objects	O
(	O
shapes	O
,	O
lines	O
and	O
points	O
)	O
are	O
grouped	O
using	O
the	O
minimum	B-Algorithm
bounding	I-Algorithm
rectangle	I-Algorithm
(	O
MBR	O
)	O
.	O
</s>
<s>
A	O
spatial	B-Language
query	I-Language
is	O
a	O
special	O
type	O
of	O
database	B-Application
query	I-Application
supported	O
by	O
spatial	B-Algorithm
databases	I-Algorithm
,	O
including	O
geodatabases	O
.	O
</s>
<s>
The	O
queries	B-Library
differ	O
from	O
non-spatial	O
SQL	B-Language
queries	B-Library
in	O
several	O
important	O
ways	O
.	O
</s>
<s>
Two	O
of	O
the	O
most	O
important	O
are	O
that	O
they	O
allow	O
for	O
the	O
use	O
of	O
geometry	O
data	O
types	O
such	O
as	O
points	O
,	O
lines	O
and	O
polygons	B-General_Concept
and	O
that	O
these	O
queries	B-Library
consider	O
the	O
spatial	O
relationship	O
between	O
these	O
geometries	O
.	O
</s>
<s>
The	O
function	O
names	O
for	O
queries	B-Library
differ	O
across	O
geodatabases	O
.	O
</s>
<s>
The	O
following	O
are	O
a	O
few	O
of	O
the	O
functions	O
built	O
into	O
PostGIS	B-Application
,	O
a	O
free	O
geodatabase	O
which	O
is	O
a	O
PostgreSQL	B-Application
extension	O
(	O
the	O
term	O
'	O
geometry	O
 '	O
refers	O
to	O
a	O
point	O
,	O
line	O
,	O
box	O
or	O
other	O
two	O
or	O
three	O
dimensional	O
shape	O
)	O
:	O
</s>
<s>
Thus	O
,	O
a	O
spatial	O
join	O
between	O
a	O
points	O
layer	O
of	O
cities	O
and	O
a	O
polygon	B-General_Concept
layer	O
of	O
countries	O
could	O
be	O
performed	O
in	O
a	O
spatially-extended	O
SQL	B-Language
statement	O
as	O
:	O
</s>
<s>
The	O
Intersect	B-Application
vector	B-Application
overlay	I-Application
operation	O
(	O
a	O
core	O
element	O
of	O
GIS	B-Application
software	I-Application
)	O
could	O
be	O
replicated	O
as	O
:	O
</s>
<s>
AllegroGraph	B-Language
–	O
a	O
graph	B-Application
database	I-Application
which	O
provides	O
a	O
mechanism	O
for	O
efficient	O
storage	O
and	O
retrieval	O
of	O
two-dimensional	O
geospatial	B-General_Concept
coordinates	O
for	O
Resource	O
Description	O
Framework	O
data	O
.	O
</s>
<s>
It	O
includes	O
an	O
extension	O
syntax	O
for	O
SPARQL	B-Language
queries	B-Library
.	O
</s>
<s>
ArangoDB	B-Operating_System
-	O
a	O
multi-model	O
database	O
which	O
provides	O
geoindexing	O
capability	O
.	O
</s>
<s>
Apache	B-General_Concept
Drill	I-General_Concept
-	O
A	O
MPP	O
SQL	B-Language
query	B-Library
engine	O
for	O
querying	B-Library
large	O
datasets	O
.	O
</s>
<s>
Drill	O
supports	O
spatial	B-General_Concept
data	I-General_Concept
types	O
and	O
functions	O
similar	O
to	O
PostgreSQL	B-Application
.	O
</s>
<s>
Elasticsearch	B-Application
is	O
a	O
document-based	O
database	B-Application
system	I-Application
that	O
supports	O
two	O
types	O
of	O
geo	O
data	O
:	O
geo_point	O
fields	O
which	O
support	O
lat/lon	O
pairs	O
,	O
and	O
geo_shape	O
fields	O
,	O
which	O
support	O
points	O
,	O
lines	O
,	O
circles	O
,	O
polygons	B-General_Concept
,	O
multi-polygons	O
,	O
etc	O
.	O
</s>
<s>
GeoMesa	B-Language
is	O
a	O
cloud-based	O
spatio-temporal	B-General_Concept
database	I-General_Concept
built	O
on	O
top	O
of	O
Apache	B-Language
Accumulo	I-Language
and	O
Apache	B-Application
Hadoop	I-Application
(	O
also	O
supports	O
Apache	B-Language
HBase	I-Language
,	O
Google	B-Application
Bigtable	B-Application
,	O
Apache	B-Application
Cassandra	I-Application
,	O
and	O
Apache	B-Language
Kafka	I-Language
)	O
.	O
</s>
<s>
GeoMesa	B-Language
supports	O
full	O
OGC	O
Simple	O
Features	O
and	O
a	O
GeoServer	O
plugin	O
.	O
</s>
<s>
H2	B-Language
supports	O
geometry	O
types	O
and	O
spatial	O
indices	O
as	O
of	O
version	O
1.3.173	O
(	O
2013-07-28	O
)	O
.	O
</s>
<s>
Any	O
edition	O
of	O
IBM	B-Application
Db2	I-Application
can	O
be	O
spatially-enabled	O
to	O
implement	O
the	O
OpenGIS	O
spatial	O
functionality	O
with	O
SQL	B-Language
spatial	O
types	O
and	O
functions	O
.	O
</s>
<s>
IBM	B-Application
Informix	I-Application
Geodetic	O
and	O
Spatial	O
datablade	O
extensions	O
auto-install	O
on	O
use	O
and	O
expand	O
Informix	B-Application
's	O
datatypes	O
to	O
include	O
multiple	O
standard	O
coordinate	O
systems	O
and	O
support	O
for	O
RTree	B-Library
indexes	O
.	O
</s>
<s>
Geodetic	O
and	O
Spatial	B-General_Concept
data	I-General_Concept
can	O
also	O
be	O
incorporated	O
with	O
Informix	B-Application
's	O
Timeseries	O
data	O
support	O
for	O
tracking	O
objects	O
in	O
motion	O
over	O
time	O
.	O
</s>
<s>
Linter	B-Application
SQL	I-Application
Server	I-Application
supports	O
spatial	O
types	O
and	O
spatial	O
functions	O
according	O
to	O
the	O
OpenGIS	O
specifications	O
.	O
</s>
<s>
MonetDB/GIS	O
extension	O
for	O
MonetDB	B-Application
adds	O
OGS	O
Simple	O
Features	O
to	O
the	O
relational	O
column-store	B-General_Concept
database	O
.	O
</s>
<s>
MySQL	B-Application
DBMS	O
implements	O
the	O
datatype	O
geometry	O
,	O
plus	O
some	O
spatial	O
functions	O
implemented	O
according	O
to	O
the	O
OpenGIS	O
specifications	O
.	O
</s>
<s>
However	O
,	O
in	O
MySQL	B-Application
version	O
5.5	O
and	O
earlier	O
,	O
functions	O
that	O
test	O
spatial	O
relationships	O
are	O
limited	O
to	O
working	O
with	O
minimum	B-Algorithm
bounding	I-Algorithm
rectangles	I-Algorithm
rather	O
than	O
the	O
actual	O
geometries	O
.	O
</s>
<s>
MySQL	B-Application
versions	O
earlier	O
than	O
5.0.16	O
only	O
supported	O
spatial	B-General_Concept
data	I-General_Concept
in	O
MyISAM	O
tables	O
.	O
</s>
<s>
PostgreSQL	B-Application
DBMS	O
(	O
database	B-Application
management	I-Application
system	I-Application
)	O
uses	O
the	O
extension	O
PostGIS	B-Application
to	O
implement	O
OGC-compliant	O
spatial	O
functionality	O
,	O
including	O
standardized	O
datatype	O
geometry	O
and	O
corresponding	O
functions	O
.	O
</s>
<s>
Redis	B-Operating_System
with	O
the	O
Geo	O
API	O
.	O
</s>
<s>
RethinkDB	B-Operating_System
supports	O
geospatial	B-General_Concept
indexes	O
in	O
2D	O
.	O
</s>
<s>
SAP	B-Application
HANA	I-Application
supports	O
geospatial	B-General_Concept
with	O
SPS08	O
.	O
</s>
<s>
Spatial	B-Application
Query	I-Application
Server	I-Application
from	O
Boeing	O
spatially	O
enables	O
Sybase	O
ASE	O
.	O
</s>
<s>
SpatiaLite	B-Language
extends	O
Sqlite	B-Language
with	O
spatial	O
datatypes	O
,	O
functions	O
,	O
and	O
utilities	O
.	O
</s>
<s>
Tarantool	B-Operating_System
supports	O
geospatial	B-General_Concept
queries	B-Library
with	O
RTREE	B-Library
index	O
.	O
</s>
<s>
Teradata	O
Geospatial	B-General_Concept
includes	O
2D	O
spatial	O
functionality	O
(	O
OGC-compliant	O
)	O
in	O
its	O
data	O
warehouse	O
system	O
.	O
</s>
<s>
Vertica	O
Place	O
,	O
the	O
geo-spatial	O
extension	O
for	O
HP	O
Vertica	O
,	O
adds	O
OGC-compliant	O
spatial	O
features	O
to	O
the	O
relational	O
column-store	B-General_Concept
database	O
.	O
</s>
