<s>
Bigtable	B-Application
is	O
a	O
fully	O
managed	O
wide-column	O
and	O
key-value	O
NoSQL	B-General_Concept
database	O
service	O
for	O
large	O
analytical	O
and	O
operational	O
workloads	O
as	O
part	O
of	O
the	B-Application
Google	I-Application
Cloud	O
portfolio	O
.	O
</s>
<s>
Bigtable	B-Application
development	O
began	O
in	O
2004	O
.	O
</s>
<s>
It	O
is	O
now	O
used	O
by	O
a	O
number	O
of	O
Google	B-Application
applications	O
,	O
such	O
as	O
Google	B-Application
Analytics	I-Application
,	O
web	O
indexing	O
,	O
MapReduce	B-Operating_System
,	O
which	O
is	O
often	O
used	O
for	O
generating	O
and	O
modifying	O
data	O
stored	O
in	O
Bigtable	B-Application
,	O
Google	B-Application
Maps	I-Application
,	O
Google	B-Application
Books	I-Application
search	O
,	O
"	O
My	O
Search	O
History	O
"	O
,	O
Google	B-Application
Earth	I-Application
,	O
Blogger.com,	O
Google	B-Protocol
Code	I-Protocol
hosting	O
,	O
YouTube	B-General_Concept
,	O
and	O
Gmail	B-Application
.	O
</s>
<s>
Google	B-Application
's	I-Application
reasons	O
for	O
developing	O
its	O
own	O
database	O
include	O
scalability	O
and	O
better	O
control	O
of	O
performance	O
characteristics	O
.	O
</s>
<s>
Google	B-Application
's	I-Application
Spanner	B-Operating_System
RDBMS	I-Operating_System
is	O
layered	O
on	O
an	O
implementation	O
of	O
Bigtable	B-Application
with	O
a	O
Paxos	B-Operating_System
group	O
for	O
two-phase	B-General_Concept
commits	I-General_Concept
to	O
each	O
table	O
.	O
</s>
<s>
Google	B-Operating_System
F1	I-Operating_System
was	O
built	O
using	O
Spanner	B-Operating_System
to	O
replace	O
an	O
implementation	O
based	O
on	O
MySQL	B-Application
.	O
</s>
<s>
Apache	B-Language
HBase	I-Language
and	O
Cassandra	B-Application
are	O
some	O
of	O
the	O
best	O
known	O
open	O
source	O
projects	O
that	O
were	O
modeled	O
after	O
Bigtable	B-Application
.	O
</s>
<s>
On	O
May	O
6	O
,	O
2015	O
,	O
a	O
public	O
version	O
of	O
Bigtable	B-Application
was	O
made	O
available	O
as	O
a	O
part	O
of	O
Google	B-General_Concept
Cloud	I-General_Concept
under	O
the	O
name	O
Cloud	O
Bigtable	B-Application
.	O
</s>
<s>
As	O
of	O
January	O
2022	O
,	O
Bigtable	B-Application
manages	O
over	O
10	O
Exabytes	O
of	O
data	O
and	O
serves	O
more	O
than	O
5	O
billion	O
requests	O
per	O
second	O
.	O
</s>
<s>
On	O
January	O
27	O
,	O
2022	O
,	O
Google	B-Application
announced	O
a	O
number	O
of	O
updates	O
to	O
Bigtable	B-Application
,	O
including	O
automated	O
scalability	O
.	O
</s>
<s>
Bigtable	B-Application
is	O
one	O
of	O
the	O
prototypical	O
examples	O
of	O
a	O
wide-column	B-Application
store	I-Application
.	O
</s>
<s>
It	O
is	O
built	O
on	O
Colossus	B-Application
(	O
Google	B-Application
File	I-Application
System	I-Application
)	O
,	O
Chubby	O
Lock	O
Service	O
,	O
SSTable	O
(	O
log-structured	O
storage	O
like	O
LevelDB	B-Language
)	O
and	O
a	O
few	O
other	O
Google	B-Application
technologies	O
.	O
</s>
<s>
Bigtable	B-Application
is	O
designed	O
to	O
scale	O
into	O
the	O
petabyte	O
range	O
across	O
"	O
hundreds	O
or	O
thousands	O
of	O
machines	O
,	O
and	O
to	O
make	O
it	O
easy	O
to	O
add	O
more	O
machines	O
 [ to ] 	O
the	O
system	O
and	O
automatically	O
start	O
taking	O
advantage	O
of	O
those	O
resources	O
without	O
any	O
reconfiguration	O
"	O
.	O
</s>
<s>
For	O
example	O
,	O
Google	B-Application
's	I-Application
copy	O
of	O
the	O
web	O
can	O
be	O
stored	O
in	O
a	O
bigtable	B-Application
where	O
the	O
row	O
key	O
is	O
a	O
domain-reversed	B-Protocol
URL	I-Protocol
,	O
and	O
columns	O
describe	O
various	O
properties	O
of	O
a	O
web	O
page	O
,	O
with	O
one	O
particular	O
column	O
holding	O
the	O
page	O
itself	O
.	O
</s>
<s>
Each	O
cell	O
of	O
a	O
bigtable	B-Application
can	O
have	O
zero	O
or	O
more	O
timestamped	O
versions	O
of	O
the	O
data	O
.	O
</s>
<s>
Another	O
function	O
of	O
the	O
timestamp	O
is	O
to	O
allow	O
for	O
both	O
versioning	B-Architecture
and	O
garbage	B-General_Concept
collection	I-General_Concept
of	O
expired	O
data	O
.	O
</s>
<s>
A	O
bigtable	B-Application
is	O
somewhat	O
like	O
a	O
mapreduce	B-Operating_System
worker	O
pool	O
in	O
that	O
thousands	O
to	O
hundreds	O
of	O
thousands	O
of	O
tablet	O
shards	O
may	O
be	O
served	O
by	O
hundreds	O
to	O
thousands	O
of	O
BigTable	B-Application
servers	O
.	O
</s>
<s>
When	O
Table	O
size	O
threaten	O
to	O
grow	O
beyond	O
a	O
specified	O
limit	O
,	O
the	O
tablets	O
may	O
be	O
compressed	O
using	O
the	O
algorithm	O
BMDiff	O
and	O
the	O
Zippy	O
compression	O
algorithm	O
publicly	O
known	O
and	O
open-sourced	O
as	O
Snappy	B-Language
,	O
which	O
is	O
a	O
less	O
space-optimal	O
variation	O
of	O
LZ77	O
but	O
more	O
efficient	O
in	O
terms	O
of	O
computing	O
time	O
.	O
</s>
