<s>
GT.M	B-Application
is	O
a	O
high-throughput	O
key	B-Data_Structure
–	I-Data_Structure
value	I-Data_Structure
database	I-Data_Structure
engine	O
optimized	O
for	O
transaction	B-General_Concept
processing	I-General_Concept
.	O
</s>
<s>
(	O
It	O
is	O
a	O
type	O
also	O
referred	O
to	O
as	O
"	O
schema-less	O
"	O
,	O
"	O
schema-free	O
"	O
,	O
or	O
"	O
NoSQL	B-General_Concept
"	O
.	O
)	O
</s>
<s>
GT.M	B-Application
is	O
also	O
an	O
application	O
development	O
platform	O
and	O
a	O
compiler	B-Language
for	O
the	O
ISO	O
standard	O
M	B-Language
language	O
,	O
also	O
known	O
as	O
MUMPS	B-Language
.	O
</s>
<s>
GT.M	B-Application
,	O
an	O
abbreviation	O
for	O
Greystone	O
Technology	O
M	B-Language
,	O
was	O
developed	O
by	O
the	O
Greystone	O
Technology	O
Corp	O
in	O
the	O
1980s	O
.	O
</s>
<s>
It	O
is	O
an	O
implementation	O
of	O
ANSI	O
standard	O
M	B-Language
for	O
AIX	B-Application
and	O
Linux	B-Application
.	O
</s>
<s>
In	O
addition	O
to	O
preserving	O
the	O
traditional	O
features	O
of	O
M	B-Language
,	O
GT.M	B-Application
also	O
offers	O
an	O
optimizing	B-Application
compiler	I-Application
that	O
produces	O
object	O
code	O
that	O
does	O
not	O
require	O
internal	O
interpreters	B-Application
during	O
execution	O
.	O
</s>
<s>
The	O
database	O
engine	O
,	O
made	O
open	B-License
source	I-License
in	O
2000	O
,	O
is	O
maintained	O
by	O
FIS	O
.	O
</s>
<s>
GT.M	B-Application
is	O
used	O
as	O
the	O
backend	O
of	O
their	O
FIS	O
Profile	O
banking	O
application	O
,	O
and	O
it	O
powers	O
banks	O
in	O
Spain	O
,	O
France	O
,	O
Italy	O
,	O
the	O
Netherlands	O
,	O
Romania	O
and	O
India	O
;	O
Capital	O
One	O
360	O
in	O
the	O
United	O
States	O
;	O
Tangerine	O
(	O
Scotiabank	O
)	O
in	O
Canada	O
;	O
Atom	O
Bank	O
;	O
Tandem	O
Bank	O
;	O
Sainsbury	O
's	O
Bank	O
;	O
Scottish	O
Widows	O
and	O
Barclays	O
Direct	O
in	O
the	O
UK	O
.	O
</s>
<s>
It	O
is	O
also	O
used	O
as	O
an	O
open	B-License
source	I-License
backend	O
for	O
the	O
Electronic	B-Application
Health	I-Application
Record	I-Application
system	O
WorldVistA	O
and	O
other	O
open	B-License
source	I-License
EHRs	B-Application
such	O
as	O
Medsphere	O
's	O
OpenVista	B-Application
.	O
</s>
<s>
It	O
is	O
listed	O
as	O
an	O
open	B-License
source	I-License
healthcare	O
solution	O
partner	O
of	O
Red	O
Hat	O
.	O
</s>
<s>
GT.M	B-Application
consists	O
of	O
a	O
language	O
subsystem	O
,	O
a	O
database	O
subsystem	O
,	O
and	O
utility	O
programs	O
.	O
</s>
<s>
Like	O
MUMPS	B-Language
,	O
GT.M	B-Application
has	O
no	O
real	O
concept	O
of	O
different	O
data	O
types	O
,	O
though	O
strings	O
(	O
those	O
which	O
are	O
not	O
fully	O
numeric	O
)	O
must	O
be	O
placed	O
in	O
quotes	O
to	O
differentiate	O
them	O
from	O
variables	O
.	O
</s>
<s>
Numbers	O
can	O
be	O
treated	O
as	O
strings	O
of	O
digits	O
,	O
or	O
strings	O
can	O
be	O
treated	O
as	O
numbers	O
by	O
numeric	O
operators	O
(	O
coerced	O
,	O
in	O
MUMPS	B-Language
terminology	O
)	O
.	O
</s>
<s>
Data	O
is	O
treated	O
based	O
on	O
context	O
and	O
the	O
rules	O
of	O
GT.M	B-Application
:	O
1+	O
"	O
42	O
"	O
yields	O
the	O
result	O
43	O
,	O
the	O
first	O
character	O
of	O
43	O
is	O
4	O
,	O
and	O
20+	O
"	O
30	O
DUCKS	O
"	O
is	O
50	O
(	O
as	O
non-numeric	O
characters	O
are	O
dropped	O
during	O
numeric	O
operations	O
)	O
.	O
</s>
<s>
GT.M	B-Application
uses	O
Unicode	O
(	O
ISO/IEC	O
-10646	O
)	O
for	O
international	O
character	O
set	O
support	O
.	O
</s>
<s>
The	O
logical	O
database	O
of	O
a	O
GT.M	B-Application
process	O
consists	O
of	O
one	O
or	O
more	O
global	O
variable	O
name	O
spaces	O
,	O
each	O
consisting	O
of	O
unlimited	O
number	O
of	O
global	O
variables	O
.	O
</s>
<s>
The	O
database	O
engine	O
is	O
daemonless	O
and	O
processes	O
accessing	O
the	O
database	O
operate	O
with	O
normal	O
user	O
and	O
group	O
ids	O
-	O
a	O
process	O
has	O
access	O
to	O
a	O
database	O
file	O
if	O
and	O
only	O
if	O
the	O
ownership	O
and	O
permissions	O
of	O
that	O
database	O
file	O
(	O
plus	O
any	O
layered	O
access	O
control	O
such	O
as	O
SELinux	B-Application
)	O
permits	O
access	O
.	O
</s>
<s>
The	O
database	O
engine	O
also	O
supports	O
transaction	B-General_Concept
processing	I-General_Concept
.	O
</s>
<s>
GT.M	B-Application
uses	O
optimistic	B-Operating_System
concurrency	I-Operating_System
control	I-Operating_System
to	O
manage	O
transactions	O
.	O
</s>
<s>
GT.M	B-Application
is	O
distributed	O
with	O
reference	O
plug-in	O
that	O
uses	O
GnuPG	B-Application
.	O
</s>
<s>
The	O
GT.M	B-Application
run-time	O
provides	O
dynamic	O
storage	O
allocation	O
with	O
garbage	O
collection	O
.	O
</s>
<s>
GT.M	B-Application
routines	O
are	O
dynamically	O
compiled	B-Language
and	O
linked	O
for	O
execution	O
in	O
the	O
address	O
space	O
of	O
each	O
process	O
.	O
</s>
<s>
With	O
the	O
exception	O
of	O
the	O
32-bit	O
implementation	O
of	O
GT.M	B-Application
for	O
the	O
x86	B-Operating_System
Linux	B-Application
platform	O
,	O
object	O
modules	O
can	O
also	O
be	O
placed	O
in	O
shared	O
libraries	O
with	O
the	O
standard	O
ld	O
command	O
,	O
in	O
which	O
case	O
the	O
memory	O
used	O
is	O
shared	O
.	O
</s>
<s>
This	O
is	O
important	O
because	O
an	O
application	O
such	O
as	O
VistA	B-Application
has	O
over	O
20,000	O
routines	O
whose	O
compiled	B-Language
object	O
code	O
exceeds	O
200MB	O
.	O
</s>
<s>
A	O
large	O
hospital	O
running	O
VistA	B-Application
can	O
have	O
thousands	O
of	O
concurrently	O
running	O
user	O
processes	O
.	O
</s>
<s>
With	O
a	O
couple	O
of	O
small	O
exceptions	O
,	O
GT.M	B-Application
includes	O
a	O
nearly	O
complete	O
implementation	O
of	O
(	O
affectionately	O
known	O
as	O
MUMPS	B-Language
for	O
historical	O
reasons	O
)	O
.	O
</s>
<s>
In	O
GT.M	B-Application
,	O
M	B-Language
code	O
can	O
freely	O
call	O
out	O
to	O
C	B-Language
code	O
(	O
or	O
code	O
in	O
other	O
languages	O
with	O
a	O
C	B-Language
compatible	O
interface	O
)	O
,	O
and	O
C	B-Language
code	O
can	O
freely	O
call	O
in	O
to	O
M	B-Language
code	O
(	O
so	O
the	O
top	O
level	O
program	O
can	O
be	O
a	O
C	B-Language
main( )	O
)	O
.	O
</s>
<s>
For	O
example	O
,	O
is	O
a	O
,	O
for	O
access	O
from	O
Python	B-Language
or	O
binding	O
for	O
Erlang	B-Operating_System
.	O
</s>
<s>
Web	O
services	O
written	O
in	O
GT.M	B-Application
can	O
be	O
deployed	O
under	O
an	O
Internet	B-Protocol
super	I-Protocol
server	I-Protocol
such	O
as	O
inetd	B-Protocol
or	O
xinetd	B-Operating_System
.	O
</s>
<s>
GT.M	B-Application
is	O
fully	O
supported	O
on	O
the	O
following	O
platforms	O
:	O
</s>
<s>
Linux	B-Application
on	O
x86_64	B-Device
and	O
IA-32	B-Device
(	O
x86	B-Operating_System
)	O
architectures	O
.	O
</s>
<s>
The	O
YottaDB	O
fork	B-Application
of	O
GT.M	B-Application
adds	O
support	O
for	O
ARM	B-Architecture
.	O
</s>
<s>
GT.M	B-Application
is	O
no	O
longer	O
supported	O
on	O
these	O
platforms	O
:	O
</s>
<s>
The	O
code	O
base	O
for	O
GT.M	B-Application
on	O
Linux	B-Application
on	O
IA-32	B-Device
(	O
x86	B-Operating_System
)	O
includes	O
changes	O
needed	O
to	O
run	O
on	O
Cygwin	B-Language
on	O
Microsoft	B-Application
Windows	I-Application
but	O
this	O
is	O
not	O
a	O
supported	O
platform	O
.	O
</s>
<s>
On	O
Linux	B-Application
on	O
x86-64	B-Device
&	O
IA-32	B-Device
(	O
x86	B-Operating_System
)	O
,	O
and	O
on	O
OpenVMS	B-Operating_System
on	O
Alpha/AXP	B-Device
,	O
GT.M	B-Application
is	O
released	O
as	O
Free	O
/	O
Open	B-License
Source	I-License
Software	O
(	O
FOSS	O
)	O
under	O
the	O
terms	O
of	O
the	O
.	O
</s>
<s>
GT.M	B-Application
is	O
predominantly	O
used	O
in	O
healthcare	O
and	O
financial	O
services	O
industry	O
.	O
</s>
<s>
The	O
first	O
production	O
use	O
of	O
GT.M	B-Application
was	O
in	O
1986	O
at	O
the	O
Elvis	O
Presley	O
Memorial	O
Trauma	O
Center	O
in	O
Memphis	O
,	O
Tennessee	O
.	O
</s>
<s>
SQL	B-Language
and	O
ODBC	B-Application
access	O
to	O
GT.M	B-Application
databases	O
exists	O
as	O
separate	O
commercial	O
products	O
.	O
</s>
