<s>
A	O
database	B-Device
machines	I-Device
or	O
back	B-Device
end	I-Device
processor	I-Device
is	O
a	O
computer	O
or	O
special	O
hardware	B-Architecture
that	O
stores	O
and	O
retrieves	O
data	O
from	O
a	O
database	O
.	O
</s>
<s>
It	O
is	O
specially	O
designed	O
for	O
database	O
access	O
and	O
is	O
tightly	O
coupled	O
to	O
the	O
main	O
(	O
front-end	B-Architecture
)	O
computer(s )	O
by	O
a	O
high-speed	O
channel	O
,	O
whereas	O
a	O
database	B-Application
server	I-Application
is	O
a	O
general-purpose	O
computer	O
that	O
holds	O
a	O
database	O
and	O
it	O
's	O
loosely	O
coupled	O
via	O
a	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
to	O
its	O
clients	B-Protocol
.	O
</s>
<s>
Database	B-Device
machines	I-Device
can	O
retrieve	O
large	O
amount	O
of	O
data	O
using	O
hundreds	B-Operating_System
to	I-Operating_System
thousands	I-Operating_System
of	O
microprocessors	B-Architecture
with	O
database	B-General_Concept
software	I-General_Concept
.	O
</s>
<s>
The	O
front	B-Architecture
end	I-Architecture
processor	O
asks	O
the	O
back	B-Architecture
end	I-Architecture
(	O
typically	O
sending	O
a	O
query	O
expressed	O
in	O
a	O
query	B-Language
language	I-Language
)	O
the	O
data	O
and	O
further	O
processes	O
it	O
.	O
</s>
<s>
The	O
back	B-Device
end	I-Device
processor	I-Device
on	O
the	O
other	O
hand	O
analyzes	O
and	O
stores	O
the	O
data	O
from	O
the	O
front	B-Architecture
end	I-Architecture
processor	O
.	O
</s>
<s>
Back	B-Device
end	I-Device
processors	I-Device
result	O
in	O
higher	O
performance	O
,	O
increasing	O
host	O
main	B-General_Concept
memory	I-General_Concept
,	O
increasing	O
database	B-Application
recovery	I-Application
and	O
security	O
,	O
and	O
decreasing	O
cost	O
to	O
manufacture	O
.	O
</s>
<s>
Britton-Lee	O
(	O
IDM	O
)	O
,	O
Tandem	O
(	O
Non-Stop	B-Architecture
System	I-Architecture
)	O
,	O
and	O
Teradata	O
(	O
DBC	B-Device
)	O
all	O
offered	O
early	O
commercial	O
specialized	O
database	B-Device
machines	I-Device
.	O
</s>
<s>
A	O
more	O
recent	O
example	O
was	O
Oracle	B-Device
Exadata	I-Device
.	O
</s>
