<s>
Array	B-General_Concept
database	I-General_Concept
management	I-General_Concept
systems	I-General_Concept
(	O
array	B-Data_Structure
DBMSs	O
)	O
provide	O
database	B-Application
services	O
specifically	O
for	O
arrays	O
(	O
also	O
called	O
raster	B-Algorithm
data	I-Algorithm
)	O
,	O
that	O
is	O
:	O
homogeneous	O
collections	O
of	O
data	O
items	O
(	O
often	O
called	O
pixels	B-Algorithm
,	O
voxels	B-Algorithm
,	O
etc	O
.	O
</s>
<s>
Such	O
arrays	O
tend	O
to	O
be	O
Big	B-Application
Data	I-Application
,	O
with	O
single	O
objects	O
frequently	O
ranging	O
into	O
Terabyte	O
and	O
soon	O
Petabyte	O
sizes	O
;	O
for	O
example	O
,	O
today	O
's	O
earth	O
and	O
space	O
observation	O
archives	O
typically	O
grow	O
by	O
Terabytes	O
a	O
day	O
.	O
</s>
<s>
Array	B-Data_Structure
databases	B-Application
aim	O
at	O
offering	O
flexible	O
,	O
scalable	B-Architecture
storage	O
and	O
retrieval	O
on	O
this	O
information	O
category	O
.	O
</s>
<s>
In	O
the	O
same	O
style	O
as	O
standard	O
database	B-Application
systems	I-Application
do	O
on	O
sets	O
,	O
Array	B-Data_Structure
DBMSs	O
offer	O
scalable	B-Architecture
,	O
flexible	O
storage	O
and	O
flexible	O
retrieval/manipulation	O
on	O
arrays	O
of	O
(	O
conceptually	O
)	O
unlimited	O
size	O
.	O
</s>
<s>
As	O
in	O
practice	O
arrays	O
never	O
appear	O
standalone	O
,	O
such	O
an	O
array	B-Data_Structure
model	O
normally	O
is	O
embedded	O
into	O
some	O
overall	O
data	O
model	O
,	O
such	O
as	O
the	O
relational	O
model	O
.	O
</s>
<s>
Management	O
of	O
arrays	O
requires	O
novel	O
techniques	O
,	O
particularly	O
due	O
to	O
the	O
fact	O
that	O
traditional	O
database	B-Application
tuples	O
and	O
objects	O
tend	O
to	O
fit	O
well	O
into	O
a	O
single	O
database	B-Application
page	O
a	O
unit	O
of	O
disk	O
access	O
on	O
server	O
,	O
typically	O
4KB	O
while	O
array	B-Data_Structure
objects	O
easily	O
can	O
span	O
several	O
media	O
.	O
</s>
<s>
The	O
prime	O
task	O
of	O
the	O
array	B-Data_Structure
storage	O
manager	O
is	O
to	O
give	O
fast	O
access	O
to	O
large	O
arrays	O
and	O
sub-arrays	O
.	O
</s>
<s>
Array	B-Data_Structure
DBMSs	O
offer	O
query	B-Language
languages	I-Language
giving	O
declarative	B-Language
access	O
to	O
such	O
arrays	O
,	O
allowing	O
to	O
create	O
,	O
manipulate	O
,	O
search	O
,	O
and	O
delete	O
them	O
.	O
</s>
<s>
Like	O
with	O
,	O
e.g.	O
,	O
SQL	B-Language
,	O
expressions	O
of	O
arbitrary	O
complexity	O
can	O
be	O
built	O
on	O
top	O
of	O
a	O
set	O
of	O
core	O
array	B-Data_Structure
operations	O
.	O
</s>
<s>
Due	O
to	O
the	O
extensions	O
made	O
in	O
the	O
data	O
and	O
query	O
model	O
,	O
Array	B-Data_Structure
DBMSs	O
sometimes	O
are	O
subsumed	O
under	O
the	O
NoSQL	B-General_Concept
category	O
,	O
in	O
the	O
sense	O
of	O
"	O
not	B-General_Concept
only	I-General_Concept
SQL	I-General_Concept
"	O
.	O
</s>
<s>
Query	B-Language
optimization	I-Language
and	O
parallelization	B-Operating_System
are	O
important	O
for	O
achieving	O
scalability	B-Architecture
;	O
actually	O
,	O
many	O
array	B-Data_Structure
operators	O
lend	O
themselves	O
well	O
towards	O
parallel	O
evaluation	O
,	O
by	O
processing	O
each	O
tile	O
on	O
separate	O
nodes	O
or	O
cores	O
.	O
</s>
<s>
Important	O
application	O
domains	O
of	O
Array	B-Data_Structure
DBMSs	O
include	O
Earth	O
,	O
Space	O
,	O
Life	O
,	O
and	O
Social	O
sciences	O
,	O
as	O
well	O
as	O
the	O
related	O
commercial	O
applications	O
(	O
such	O
as	O
hydrocarbon	O
exploration	O
in	O
industry	O
and	O
OLAP	B-Application
in	O
business	O
)	O
.	O
</s>
<s>
The	O
relational	B-Application
data	I-Application
model	I-Application
,	O
which	O
is	O
prevailing	O
today	O
,	O
does	O
not	O
directly	O
support	O
the	O
array	B-Data_Structure
paradigm	O
to	O
the	O
same	O
extent	O
as	O
sets	O
and	O
tuples	O
.	O
</s>
<s>
ISO	O
SQL	B-Language
lists	O
an	O
array-valued	O
attribute	O
type	O
,	O
but	O
this	O
is	O
only	O
one-dimensional	O
,	O
with	O
almost	O
no	O
operational	O
support	O
,	O
and	O
not	O
usable	O
for	O
the	O
application	O
domains	O
of	O
Array	B-Data_Structure
DBMSs	O
.	O
</s>
<s>
Another	O
option	O
is	O
to	O
resort	O
to	O
BLOBs	B-General_Concept
(	O
"	O
binary	B-General_Concept
large	I-General_Concept
objects	I-General_Concept
"	O
)	O
which	O
are	O
the	O
equivalent	O
to	O
files	O
:	O
byte	O
strings	O
of	O
(	O
conceptually	O
)	O
unlimited	O
length	O
,	O
but	O
again	O
without	O
any	O
query	O
language	O
functionality	O
,	O
such	O
as	O
multi-dimensional	O
subsetting	O
.	O
</s>
<s>
First	O
significant	O
work	O
in	O
going	O
beyond	O
BLOBs	B-General_Concept
has	O
been	O
established	O
with	O
PICDMS	O
.	O
</s>
<s>
This	O
system	O
offers	O
the	O
precursor	O
of	O
a	O
2-D	O
array	B-Data_Structure
query	O
language	O
,	O
albeit	O
still	O
procedural	O
and	O
without	O
suitable	O
storage	O
support	O
.	O
</s>
<s>
A	O
first	O
declarative	B-Language
query	O
language	O
suitable	O
for	O
multiple	O
dimensions	O
and	O
with	O
an	O
algebra-based	O
semantics	O
has	O
been	O
published	O
by	O
Baumann	O
,	O
together	O
with	O
a	O
scalable	B-Architecture
architecture	O
.	O
</s>
<s>
Another	O
array	B-Data_Structure
database	B-Application
language	O
,	O
constrained	O
to	O
2-D	O
,	O
has	O
been	O
presented	O
by	O
Marathe	O
and	O
Salem	O
.	O
</s>
<s>
;	O
in	O
their	O
model	O
,	O
called	O
NCRA	O
,	O
they	O
extend	O
a	O
nested	O
relational	O
calculus	O
with	O
multidimensional	O
arrays	O
;	O
among	O
the	O
results	O
are	O
important	O
contributions	O
on	O
array	B-Data_Structure
query	O
complexity	O
analysis	O
.	O
</s>
<s>
A	O
map	O
algebra	O
,	O
suitable	O
for	O
2-D	O
and	O
3-D	O
spatial	O
raster	B-Algorithm
data	I-Algorithm
,	O
has	O
been	O
published	O
by	O
Mennis	O
et	O
al	O
.	O
</s>
<s>
In	O
terms	O
of	O
Array	B-General_Concept
DBMS	I-General_Concept
implementations	O
,	O
the	O
rasdaman	B-Application
system	O
has	O
the	O
longest	O
implementation	O
track	O
record	O
of	O
n-D	O
arrays	O
with	O
full	O
query	O
support	O
.	O
</s>
<s>
Oracle	B-Application
GeoRaster	I-Application
offers	O
chunked	O
storage	O
of	O
2-D	O
raster	O
maps	O
,	O
albeit	O
without	O
SQL	B-Language
integration	O
.	O
</s>
<s>
TerraLib	B-Application
is	O
an	O
open-source	O
GIS	O
software	O
that	O
extends	O
object-relational	O
DBMS	O
technology	O
to	O
handle	O
spatio-temporal	O
data	O
types	O
;	O
while	O
main	O
focus	O
is	O
on	O
vector	O
data	O
,	O
there	O
is	O
also	O
some	O
support	O
for	O
rasters	O
.	O
</s>
<s>
Starting	O
with	O
version	O
2.0	O
,	O
PostGIS	B-Application
embeds	O
raster	O
support	O
for	O
2-D	O
rasters	O
;	O
a	O
special	O
function	O
offers	O
declarative	B-Language
raster	O
query	O
functionality	O
.	O
</s>
<s>
SciQL	O
is	O
an	O
array	B-Data_Structure
query	O
language	O
being	O
added	O
to	O
the	O
MonetDB	B-Application
DBMS	O
.	O
</s>
<s>
SciDB	B-Operating_System
is	O
a	O
more	O
recent	O
initiative	O
to	O
establish	O
array	B-Data_Structure
database	B-Application
support	O
.	O
</s>
<s>
Like	O
SciQL	O
,	O
arrays	O
are	O
seen	O
as	O
an	O
equivalent	O
to	O
tables	O
,	O
rather	O
than	O
a	O
new	O
attribute	O
type	O
as	O
in	O
rasdaman	B-Application
and	O
PostGIS	B-Application
.	O
</s>
<s>
For	O
the	O
special	O
case	O
of	O
sparse	B-Algorithm
data	I-Algorithm
,	O
OLAP	B-Application
data	O
cubes	O
are	O
well	O
established	O
;	O
they	O
store	O
cell	O
values	O
together	O
with	O
their	O
location	O
an	O
adequate	O
compression	O
technique	O
in	O
face	O
of	O
the	O
few	O
locations	O
carrying	O
valid	O
information	O
at	O
all	O
and	O
operate	O
with	O
SQL	B-Language
on	O
them	O
.	O
</s>
<s>
As	O
this	O
technique	O
does	B-Architecture
not	I-Architecture
scale	I-Architecture
in	O
density	O
,	O
standard	O
databases	B-Application
are	O
not	O
used	O
today	O
for	O
dense	O
data	O
,	O
like	O
satellite	O
images	O
,	O
where	O
most	O
cells	O
carry	O
meaningful	O
information	O
;	O
rather	O
,	O
proprietary	O
ad	O
hoc	O
implementations	O
prevail	O
in	O
scientific	O
data	O
management	O
and	O
similar	O
situations	O
.	O
</s>
<s>
Hence	O
,	O
this	O
is	O
where	O
Array	B-Data_Structure
DBMSs	O
can	O
make	O
a	O
particular	O
contribution	O
.	O
</s>
<s>
Generally	O
,	O
Array	B-Data_Structure
DBMSs	O
are	O
an	O
emerging	O
technology	O
.	O
</s>
<s>
While	O
operationally	O
deployed	O
systems	O
exist	O
,	O
like	O
Oracle	B-Application
GeoRaster	I-Application
,	O
PostGIS	B-Application
2.0	I-Application
and	O
rasdaman	B-Application
,	O
there	O
are	O
still	O
many	O
open	O
research	O
questions	O
,	O
including	O
query	O
language	O
design	O
and	O
formalization	O
,	O
query	B-Language
optimization	I-Language
,	O
parallelization	B-Operating_System
and	O
distributed	B-Architecture
processing	I-Architecture
,	O
and	O
scalability	B-Architecture
issues	O
in	O
general	O
.	O
</s>
<s>
Besides	O
,	O
scientific	O
communities	O
still	O
appear	O
reluctant	O
in	O
taking	O
up	O
array	B-Data_Structure
database	B-Application
technology	O
and	O
tend	O
to	O
favor	O
specialized	O
,	O
proprietary	O
technology	O
.	O
</s>
<s>
When	O
adding	O
arrays	O
to	O
databases	B-Application
,	O
all	O
facets	O
of	O
database	B-Application
design	O
need	O
to	O
be	O
reconsidered	O
ranging	O
from	O
conceptual	O
modeling	O
(	O
such	O
as	O
suitable	O
operators	O
)	O
over	O
storage	O
management	O
(	O
such	O
as	O
management	O
of	O
arrays	O
spanning	O
multiple	O
media	O
)	O
to	O
query	B-Application
processing	I-Application
(	O
such	O
as	O
efficient	O
processing	O
strategies	O
)	O
.	O
</s>
<s>
Formally	O
,	O
an	O
array	B-Data_Structure
A	O
is	O
given	O
by	O
a	O
(	O
total	O
or	O
partial	O
)	O
function	O
A	O
:	O
X	O
→	O
V	O
where	O
X	O
,	O
the	O
domain	O
is	O
a	O
d-dimensional	O
integer	O
interval	O
for	O
some	O
d0	O
and	O
V	O
,	O
called	O
range	O
,	O
is	O
some	O
(	O
non-empty	O
)	O
value	O
set	O
;	O
in	O
set	O
notation	O
,	O
this	O
can	O
be	O
rewritten	O
as	O
{	O
(	O
p	O
,	O
v	O
)	O
|	O
p	O
in	O
X	O
,	O
v	O
in	O
V	O
}	O
.	O
</s>
<s>
Each	O
(	O
p	O
,	O
v	O
)	O
in	O
A	O
denotes	O
an	O
array	B-Data_Structure
element	I-Data_Structure
or	O
cell	O
,	O
and	O
following	O
common	O
notation	O
we	O
write	O
A[p]	O
=	O
v	O
.	O
Examples	O
for	O
X	O
include	O
0	O
..	O
767	O
×	O
0	O
..	O
1023	O
(	O
for	O
XGA	O
sized	O
images	O
)	O
,	O
examples	O
for	O
V	O
include	O
0	O
..	O
255	O
for	O
8-bit	O
greyscale	O
images	O
and	O
0	O
..	O
255	O
×	O
0	O
..	O
255	O
×	O
0	O
..	O
255	O
for	O
standard	O
RGB	O
imagery	O
.	O
</s>
<s>
Following	O
established	O
database	B-Application
practice	O
,	O
an	O
array	B-Data_Structure
query	O
language	O
should	O
be	O
declarative	B-Language
and	O
safe	O
in	O
evaluation	O
.	O
</s>
<s>
As	O
iteration	O
over	O
an	O
array	B-Data_Structure
is	O
at	O
the	O
heart	O
of	O
array	B-Data_Structure
processing	O
,	O
declarativeness	O
very	O
much	O
centers	O
on	O
this	O
aspect	O
.	O
</s>
<s>
The	O
requirement	O
,	O
then	O
,	O
is	O
that	O
conceptually	O
all	O
cells	O
should	O
be	O
inspected	O
simultaneously	O
in	O
other	O
words	O
,	O
the	O
query	O
does	O
not	O
enforce	O
any	O
explicit	O
iteration	O
sequence	O
over	O
the	O
array	B-Data_Structure
cells	O
during	O
evaluation	O
.	O
</s>
<s>
At	O
the	O
same	O
time	O
,	O
avoiding	O
explicit	O
loop	O
sequences	O
opens	O
up	O
manifold	O
optimization	B-Language
opportunities	O
.	O
</s>
<s>
As	O
an	O
example	O
for	O
array	B-Data_Structure
query	O
operators	O
the	O
rasdaman	B-Application
algebra	O
and	O
query	O
language	O
can	O
serve	O
,	O
which	O
establish	O
an	O
expression	O
language	O
over	O
a	O
minimal	O
set	O
of	O
array	B-Data_Structure
primitives	O
.	O
</s>
<s>
The	O
marray	O
operator	O
creates	O
an	O
array	B-Data_Structure
over	O
some	O
given	O
domain	O
extent	O
and	O
initializes	O
its	O
cells	O
:	O
</s>
<s>
This	O
subsetting	O
keeps	O
the	O
dimension	O
of	O
the	O
array	B-Data_Structure
;	O
to	O
reduce	O
dimension	O
by	O
extracting	O
slices	O
,	O
a	O
single	O
slicepoint	O
value	O
is	O
indicated	O
in	O
the	O
slicing	O
dimension	O
.	O
</s>
<s>
The	O
wildcard	O
operator	O
*	O
indicates	O
that	O
the	O
current	O
boundary	O
of	O
the	O
array	B-Data_Structure
is	O
to	O
be	O
used	O
;	O
note	O
that	O
arrays	O
where	O
dimension	O
boundaries	O
are	O
left	O
open	O
at	O
definition	O
time	O
may	O
change	O
size	O
in	O
that	O
dimensions	O
over	O
the	O
array	B-Data_Structure
's	O
lifetime	O
.	O
</s>
<s>
Through	O
a	O
principle	O
called	O
induced	O
operations	O
,	O
the	O
query	O
language	O
offers	O
all	O
operations	O
the	O
cell	O
type	O
offers	O
on	O
array	B-Data_Structure
level	O
,	O
too	O
.	O
</s>
<s>
The	O
condense	O
operator	O
aggregates	O
cell	O
values	O
into	O
one	O
scalar	O
result	O
,	O
similar	O
to	O
SQL	B-Language
aggregates	O
.	O
</s>
<s>
In	O
the	O
same	O
manner	O
and	O
in	O
analogy	O
to	O
SQL	B-Language
aggregates	O
,	O
a	O
number	O
of	O
further	O
shorthands	O
are	O
provided	O
,	O
including	O
counting	O
,	O
average	O
,	O
minimum	O
,	O
maximum	O
,	O
and	O
Boolean	O
quantifiers	O
.	O
</s>
<s>
The	O
induced	O
comparison	O
,	O
A	O
=	O
bucket	O
,	O
establishes	O
a	O
Boolean	O
array	B-Data_Structure
of	O
the	O
same	O
extent	O
as	O
A	O
.	O
</s>
<s>
The	O
aggregation	O
operator	O
counts	O
the	O
occurrences	O
of	O
true	O
for	O
each	O
value	O
of	O
bucket	O
,	O
which	O
subsequently	O
is	O
put	O
into	O
the	O
proper	O
array	B-Data_Structure
cell	O
of	O
the	O
1-D	O
histogram	O
array	B-Data_Structure
.	O
</s>
<s>
It	O
has	O
been	O
proven	O
that	O
the	O
expressive	O
power	O
of	O
such	O
array	B-Data_Structure
languages	O
in	O
principle	O
is	O
equivalent	O
to	O
relational	B-Application
query	I-Application
languages	O
with	O
ranking	O
.	O
</s>
<s>
Array	B-Data_Structure
storage	O
has	O
to	O
accommodate	O
arrays	O
of	O
different	O
dimensions	O
and	O
typically	O
large	O
sizes	O
.	O
</s>
<s>
Note	O
that	O
an	O
emulation	O
of	O
multi-dimensional	O
arrays	O
as	O
nested	O
lists	O
(	O
or	O
1-D	O
arrays	O
)	O
will	O
not	O
per	O
se	O
accomplish	O
this	O
and	O
,	O
therefore	O
,	O
in	O
general	O
will	O
not	O
lead	O
to	O
scalable	B-Architecture
architectures	O
.	O
</s>
<s>
Array	B-Data_Structure
partitioning	O
can	O
improve	O
access	O
to	O
array	B-Data_Structure
subsets	O
significantly	O
:	O
by	O
adjusting	O
tiling	O
to	O
the	O
access	O
pattern	O
,	O
the	O
server	O
ideally	O
can	O
fetch	O
all	O
required	O
data	O
with	O
only	O
one	O
disk	O
access	O
.	O
</s>
<s>
A	O
tile-based	O
storage	O
structure	O
suggests	O
a	O
tile-by-tile	O
processing	O
strategy	O
(	O
in	O
rasdaman	B-Application
called	O
tile	O
streaming	O
)	O
.	O
</s>
<s>
Due	O
to	O
the	O
massive	O
sizes	O
of	O
arrays	O
in	O
scientific/technical	O
applications	O
in	O
combination	O
with	O
often	O
complex	O
queries	O
,	O
optimization	B-Language
plays	O
a	O
central	O
role	O
in	O
making	O
array	B-Data_Structure
queries	O
efficient	O
.	O
</s>
<s>
Both	O
hardware	O
and	O
software	O
parallelization	B-Operating_System
can	O
be	O
applied	O
.	O
</s>
<s>
An	O
example	O
for	O
heuristic	O
optimization	B-Language
is	O
the	O
rule	O
"	O
maximum	O
value	O
of	O
an	O
array	B-Data_Structure
resulting	O
from	O
the	O
cell-wise	O
addition	O
of	O
two	O
input	O
images	O
is	O
equivalent	O
to	O
adding	O
the	O
maximum	O
values	O
of	O
each	O
input	O
array	B-Data_Structure
"	O
.	O
</s>
<s>
By	O
replacing	O
the	O
left-hand	O
variant	O
by	O
the	O
right-hand	O
expression	O
,	O
costs	O
shrink	O
from	O
three	O
(	O
costly	O
)	O
array	B-Data_Structure
traversals	O
to	O
two	O
array	B-Data_Structure
traversals	O
plus	O
one	O
(	O
cheap	O
)	O
scalar	O
operation	O
(	O
see	O
Figure	O
,	O
which	O
uses	O
the	O
SQL/MDA	O
query	O
standard	O
)	O
.	O
</s>
<s>
In	O
many	O
if	O
not	O
most	O
cases	O
where	O
some	O
phenomenon	O
is	O
sampled	O
or	O
simulated	O
the	O
result	O
is	O
a	O
rasterized	O
data	O
set	O
which	O
can	O
conveniently	O
be	O
stored	O
,	O
retrieved	O
,	O
and	O
forwarded	O
as	O
an	O
array	B-Data_Structure
.	O
</s>
<s>
Typically	O
,	O
the	O
array	B-Data_Structure
data	O
are	O
ornamented	O
with	O
metadata	O
describing	O
them	O
further	O
;	O
for	O
example	O
,	O
geographically	O
referenced	O
imagery	O
will	O
carry	O
its	O
geographic	O
position	O
and	O
the	O
coordinate	O
reference	O
system	O
in	O
which	O
it	O
is	O
expressed	O
.	O
</s>
<s>
The	O
following	O
are	O
representative	O
domains	O
in	O
which	O
large-scale	O
multi-dimensional	O
array	B-Data_Structure
data	O
are	O
handled	O
:	O
</s>
<s>
More	O
and	O
more	O
spatial	O
and	O
time	O
dimensions	O
are	O
combined	O
with	O
abstract	O
axes	O
,	O
such	O
as	O
sales	O
and	O
products	O
;	O
one	O
example	O
where	O
such	O
abstract	O
axes	O
are	O
explicitly	O
foreseen	O
is	O
the	O
[	O
Open_Geospatial_Consortium	O
|Open	O
Geospatial	O
Consortium ]	O
(	O
OGC	O
)	O
coverage	B-General_Concept
model	I-General_Concept
.	O
</s>
<s>
Many	O
communities	O
have	O
established	O
data	O
exchange	O
formats	O
,	O
such	O
as	O
HDF	B-Application
,	O
NetCDF	B-Application
,	O
and	O
TIFF	O
.	O
</s>
<s>
A	O
de	O
facto	O
standard	O
in	O
the	O
Earth	O
Science	O
communities	O
is	O
OPeNDAP	B-Application
,	O
a	O
data	O
transport	O
architecture	O
and	O
protocol	O
.	O
</s>
<s>
While	O
this	O
is	O
not	O
a	O
database	B-Application
specification	O
,	O
it	O
offers	O
important	O
components	O
that	O
characterize	O
a	O
database	B-Application
system	I-Application
,	O
such	O
as	O
a	O
conceptual	O
model	O
and	O
client/server	O
implementations	O
.	O
</s>
<s>
A	O
declarative	B-Language
geo	O
raster	O
query	O
language	O
,	O
Web	B-Application
Coverage	I-Application
Processing	I-Application
Service	I-Application
(	O
WCPS	O
)	O
,	O
has	O
been	O
standardized	O
by	O
the	O
Open	O
Geospatial	O
Consortium	O
(	O
OGC	O
)	O
.	O
</s>
<s>
In	O
June	O
2014	O
,	O
ISO/IEC	O
JTC1	O
SC32	O
WG3	O
,	O
which	O
maintains	O
the	O
SQL	B-Language
database	I-Language
standard	O
,	O
has	O
decided	O
to	O
add	O
multi-dimensional	O
array	B-Data_Structure
support	O
to	O
SQL	B-Language
as	O
a	O
new	O
column	O
type	O
,	O
based	O
on	O
the	O
initial	O
array	B-Data_Structure
support	O
available	O
since	O
the	O
2003	B-Language
version	I-Language
of	I-Language
SQL	I-Language
.	O
</s>
<s>
The	O
new	O
standard	O
,	O
adopted	O
in	O
Fall	O
2018	O
,	O
is	O
named	O
ISO	O
9075	O
SQL	B-Language
Part	O
15	O
:	O
MDA	O
(	O
Multi-Dimensional	O
Arrays	O
)	O
.	O
</s>
