<s>
The	O
DBC/1012	O
Data	B-Application
Base	I-Application
Computer	O
was	O
a	O
database	B-Device
machine	I-Device
introduced	O
by	O
Teradata	O
Corporation	O
in	O
1984	O
,	O
as	O
a	O
back-end	O
data	B-Application
base	I-Application
management	I-Application
system	I-Application
for	O
mainframe	O
computers	O
.	O
</s>
<s>
The	O
DBC/1012	O
harnessed	O
multiple	O
Intel	O
microprocessors	O
,	O
each	O
with	O
its	O
own	O
dedicated	O
disk	B-Device
drive	I-Device
,	O
by	O
interconnecting	O
them	O
with	O
the	O
Ynet	O
switching	O
network	O
in	O
a	O
massively	B-Operating_System
parallel	I-Operating_System
processing	I-Operating_System
system	O
.	O
</s>
<s>
The	O
DBC/1012	O
was	O
designed	O
to	O
manage	O
databases	B-Application
up	O
to	O
one	O
terabyte	O
(	O
1,000,000,000,000	O
characters	O
)	O
in	O
size	O
;	O
"	O
1012	O
"	O
in	O
the	O
name	O
refers	O
to	O
"	O
10	O
to	O
the	O
power	O
of	O
12	O
"	O
.	O
</s>
<s>
The	O
DBC/1012	O
was	O
designed	O
to	O
scale	O
up	O
to	O
1024	O
Ynet	O
interconnected	O
processor-disk	O
units	O
.	O
</s>
<s>
Rows	B-Application
of	O
a	O
relation	B-Application
(	O
table	O
)	O
were	O
distributed	O
by	O
hashing	O
on	O
the	O
primary	O
database	B-Data_Structure
index	I-Data_Structure
.	O
</s>
<s>
The	O
DBC/1012	O
used	O
a	O
474	O
megabyte	O
Winchester	O
disk	B-Device
drive	I-Device
with	O
an	O
average	O
seek	O
time	O
of	O
18	O
milliseconds	O
.	O
</s>
<s>
The	O
disk	B-Device
drive	I-Device
was	O
capable	O
of	O
transferring	O
data	O
at	O
1.9	O
MB/s	O
although	O
in	O
practice	O
the	O
sustainable	O
data	O
rate	O
was	O
lower	O
because	O
the	O
IO	O
pattern	O
tended	O
towards	O
random	O
access	O
and	O
transfer	O
lengths	O
of	O
8	O
to	O
12	O
kilobytes	O
.	O
</s>
<s>
The	O
storage	O
cabinet	O
was	O
60inches	O
high	O
and	O
27inches	O
wide	O
,	O
weighed	O
625	O
pounds	O
,	O
and	O
held	O
up	O
to	O
4	O
disk	B-Device
storage	I-Device
units	O
.	O
</s>
<s>
The	O
DBC/1012	O
preceded	O
the	O
advent	O
of	O
redundant	B-Architecture
array	I-Architecture
of	I-Architecture
independent	I-Architecture
disks	I-Architecture
(	O
RAID	B-Architecture
)	O
technology	O
,	O
so	O
data	O
protection	O
was	O
provided	O
by	O
the	O
"	O
fallback	O
"	O
feature	O
,	O
which	O
kept	O
a	O
logical	O
copy	O
of	O
rows	B-Application
of	O
a	O
relation	B-Application
on	O
different	O
AMPs	O
.	O
</s>
<s>
The	O
collection	O
of	O
AMPs	O
that	O
provided	O
this	O
protection	O
for	O
each	O
other	O
was	O
called	O
a	O
cluster	B-Architecture
.	O
</s>
<s>
A	O
cluster	B-Architecture
could	O
have	O
from	O
2	O
to	O
16	O
AMPs	O
.	O
</s>
<s>
The	O
product	O
could	O
be	O
integrated	O
with	O
optical	O
disc	B-Device
drives	I-Device
.	O
</s>
