<s>
H-Store	B-Application
is	O
an	O
experimental	O
database	B-Application
management	I-Application
system	I-Application
(	O
DBMS	O
)	O
.	O
</s>
<s>
It	O
was	O
designed	O
for	O
online	B-General_Concept
transaction	I-General_Concept
processing	I-General_Concept
applications	O
.	O
</s>
<s>
H-Store	B-Application
was	O
developed	O
by	O
a	O
team	O
at	O
Brown	O
University	O
,	O
Carnegie	O
Mellon	O
University	O
,	O
the	O
Massachusetts	O
Institute	O
of	O
Technology	O
,	O
and	O
Yale	O
University	O
in	O
2007	O
by	O
researchers	O
Michael	O
Stonebraker	O
,	O
Sam	O
Madden	O
,	O
Andy	O
Pavlo	O
and	O
Daniel	O
Abadi	O
.	O
</s>
<s>
H-Store	B-Application
was	O
promoted	O
as	O
a	O
new	O
class	O
of	O
parallel	O
database	B-Application
management	I-Application
systems	I-Application
,	O
called	O
NewSQL	B-General_Concept
,	O
that	O
provide	O
the	O
high-throughput	O
and	O
high-availability	O
of	O
NoSQL	B-General_Concept
systems	O
,	O
but	O
without	O
giving	O
up	O
the	O
transactional	O
consistency	O
of	O
a	O
traditional	O
DBMS	O
known	O
as	O
ACID	O
(	O
atomicity	O
,	O
consistency	O
,	O
isolation	O
and	O
durability	O
)	O
.	O
</s>
<s>
H-Store	B-Application
is	O
able	O
to	O
execute	O
transaction	B-General_Concept
processing	I-General_Concept
with	O
high	O
throughput	O
by	O
forgoing	O
many	O
features	O
of	O
traditional	O
relational	B-Application
database	I-Application
management	I-Application
systems	I-Application
.	O
</s>
<s>
H-Store	B-Application
was	O
designed	O
as	O
a	O
parallel	O
system	O
to	O
run	O
on	O
a	O
cluster	O
of	O
shared-nothing	B-Operating_System
,	O
main	O
memory	O
executor	O
nodes	O
(	O
processor	O
+	O
memory	O
+	O
storage	O
)	O
.	O
</s>
<s>
The	O
database	O
is	O
partitioned	B-General_Concept
into	O
disjoint	O
subsets	O
each	O
assigned	O
to	O
a	O
single-threaded	O
execution	O
engine	O
assigned	O
to	O
one	O
core	B-Architecture
on	O
one	O
node	O
.	O
</s>
<s>
Each	O
engine	O
has	O
exclusive	O
access	O
to	O
all	O
of	O
the	O
data	O
in	O
its	O
partition	B-General_Concept
.	O
</s>
<s>
Because	O
it	O
is	O
single-threaded	O
,	O
only	O
one	O
transaction	O
at	O
a	O
time	O
can	O
access	O
the	O
data	O
stored	O
on	O
that	O
partition	B-General_Concept
.	O
</s>
<s>
Throughput	O
is	O
increased	O
by	O
increasing	O
the	O
number	O
of	O
nodes	O
in	O
the	O
system	O
and	O
reducing	O
partition	B-General_Concept
sizes	O
.	O
</s>
<s>
H-Store	B-Application
was	O
licensed	O
under	O
the	O
BSD	B-Operating_System
license	I-Operating_System
and	O
GPL	B-License
licenses	I-License
.	O
</s>
<s>
By	O
2009	O
,	O
the	O
VoltDB	B-Application
company	O
developed	O
a	O
commercial	O
version	O
,	O
and	O
the	O
H-Store	B-Application
research	O
group	O
shut	O
down	O
in	O
2016	O
.	O
</s>
