<s>
Multidimensional	B-Language
Expressions	I-Language
(	O
MDX	O
)	O
is	O
a	O
query	B-Language
language	I-Language
for	O
online	B-Application
analytical	I-Application
processing	I-Application
(	O
OLAP	B-Application
)	O
using	O
a	O
database	B-Application
management	I-Application
system	I-Application
.	O
</s>
<s>
Much	O
like	O
SQL	B-Language
,	O
it	O
is	O
a	O
query	B-Language
language	I-Language
for	O
OLAP	B-Application
cubes	O
.	O
</s>
<s>
The	O
MultiDimensional	B-Language
eXpressions	I-Language
(	O
MDX	O
)	O
language	O
provides	O
a	O
specialized	O
syntax	O
for	O
querying	O
and	O
manipulating	O
the	O
multidimensional	O
data	O
stored	O
in	O
OLAP	B-Application
cubes	O
.	O
</s>
<s>
While	O
it	O
is	O
possible	O
to	O
translate	O
some	O
of	O
these	O
into	O
traditional	O
SQL	B-Language
,	O
it	O
would	O
frequently	O
require	O
the	O
synthesis	O
of	O
clumsy	O
SQL	B-Language
expressions	O
even	O
for	O
very	O
simple	O
MDX	O
expressions	O
.	O
</s>
<s>
MDX	O
has	O
been	O
embraced	O
by	O
a	O
wide	O
majority	O
of	O
OLAP	B-Application
vendors	O
and	O
has	O
become	O
the	O
standard	O
for	O
OLAP	B-Application
systems	O
.	O
</s>
<s>
MDX	O
was	O
first	O
introduced	O
as	O
part	O
of	O
the	O
OLE	O
DB	O
for	O
OLAP	B-Application
specification	O
in	O
1997	O
from	O
Microsoft	O
.	O
</s>
<s>
It	O
was	O
invented	O
by	O
the	O
group	O
of	O
SQL	B-Application
Server	I-Application
engineers	O
including	O
Mosha	O
Pasumansky	O
.	O
</s>
<s>
The	O
specification	O
was	O
quickly	O
followed	O
by	O
commercial	O
release	O
of	O
Microsoft	O
OLAP	B-Application
Services	I-Application
7.0	O
in	O
1998	O
and	O
later	O
by	O
Microsoft	B-Application
Analysis	I-Application
Services	I-Application
.	O
</s>
<s>
The	O
latest	O
version	O
of	O
the	O
OLE	O
DB	O
for	O
OLAP	B-Application
specification	O
was	O
issued	O
by	O
Microsoft	O
in	O
1999	O
.	O
</s>
<s>
While	O
it	O
was	O
not	O
an	O
open	O
standard	O
,	O
but	O
rather	O
a	O
Microsoft-owned	O
specification	O
,	O
it	O
was	O
adopted	O
by	O
a	O
wide	O
range	O
of	O
OLAP	B-Application
vendors	O
.	O
</s>
<s>
The	O
XML	O
for	O
Analysis	O
specification	O
referred	O
back	O
to	O
the	O
OLE	O
DB	O
for	O
OLAP	B-Application
specification	O
for	O
details	O
on	O
the	O
MDX	O
Query	B-Language
Language	I-Language
.	O
</s>
<s>
In	O
Analysis	O
Services	O
2005	O
,	O
Microsoft	O
added	O
some	O
MDX	O
Query	B-Language
Language	I-Language
extensions	O
like	O
subselects	O
.	O
</s>
<s>
Products	O
like	O
Microsoft	O
Excel	O
2007	O
started	O
to	O
use	O
these	O
new	O
MDX	O
Query	B-Language
Language	I-Language
extensions	O
.	O
</s>
<s>
In	O
2001	O
the	O
XMLA	O
Council	O
released	O
the	O
XML	O
for	O
Analysis	O
(	O
XMLA	O
)	O
standard	O
,	O
which	O
included	O
mdXML	B-Language
as	O
a	O
query	B-Language
language	I-Language
.	O
</s>
<s>
In	O
the	O
XMLA	O
1.1	O
specification	O
,	O
mdXML	B-Language
is	O
essentially	O
MDX	O
wrapped	O
in	O
the	O
XML	O
<Statement>	O
tag	O
.	O
</s>
<s>
number	O
5	O
or	O
string	O
"	O
OLAP	B-Application
"	O
or	O
it	O
can	O
be	O
returned	O
by	O
an	O
MDX	O
function	O
,	O
e.g.	O
</s>
<s>
(	O
OLEDB	O
for	O
OLAP	B-Application
MDX	O
specification	O
does	O
not	O
distinguish	O
between	O
dimension	O
and	O
hierarchy	O
data	O
types	O
.	O
</s>
<s>
Some	O
implementations	O
,	O
such	O
as	O
Microsoft	B-Application
Analysis	I-Application
Services	I-Application
,	O
treat	O
them	O
differently	O
.	O
)	O
</s>
<s>
The	O
following	O
example	O
,	O
adapted	O
from	O
the	O
SQL	B-Application
Server	I-Application
2000	O
Books	O
Online	O
,	O
shows	O
a	O
basic	O
MDX	O
query	O
that	O
uses	O
the	O
SELECT	O
statement	O
.	O
</s>
