<s>
A	O
data	B-General_Concept
lake	I-General_Concept
is	O
a	O
system	O
or	O
repository	O
of	O
data	O
stored	O
in	O
its	O
natural/raw	O
format	O
,	O
usually	O
object	O
blobs	B-General_Concept
or	O
files	O
.	O
</s>
<s>
A	O
data	B-General_Concept
lake	I-General_Concept
is	O
usually	O
a	O
single	O
store	O
of	O
data	O
including	O
raw	O
copies	O
of	O
source	O
system	O
data	O
,	O
sensor	O
data	O
,	O
social	O
data	O
etc.	O
,	O
and	O
transformed	O
data	O
used	O
for	O
tasks	O
such	O
as	O
reporting	B-General_Concept
,	O
visualization	B-Application
,	O
advanced	B-General_Concept
analytics	I-General_Concept
and	O
machine	O
learning	O
.	O
</s>
<s>
A	O
data	B-General_Concept
lake	I-General_Concept
can	O
include	O
structured	B-Application
data	I-Application
from	O
relational	B-Application
databases	I-Application
(	O
rows	O
and	O
columns	O
)	O
,	O
semi-structured	O
data	O
(	O
CSV	O
,	O
logs	O
,	O
XML	B-Protocol
,	O
JSON	B-General_Concept
)	O
,	O
unstructured	B-Application
data	I-Application
(	O
emails	O
,	O
documents	O
,	O
PDFs	B-Application
)	O
and	O
binary	O
data	O
(	O
images	O
,	O
audio	O
,	O
video	O
)	O
.	O
</s>
<s>
A	O
data	B-General_Concept
lake	I-General_Concept
can	O
be	O
established	O
"	O
on	O
premises	O
"	O
(	O
within	O
an	O
organization	O
's	O
data	O
centers	O
)	O
or	O
"	O
in	O
the	O
cloud	O
"	O
(	O
using	O
cloud	O
services	O
from	O
vendors	O
such	O
as	O
Amazon	B-Application
,	O
Microsoft	O
,	O
or	O
Google	B-Application
)	O
.	O
</s>
<s>
James	O
Dixon	O
,	O
then	O
chief	O
technology	O
officer	O
at	O
Pentaho	B-Application
,	O
coined	O
the	O
term	O
by	O
2011	O
to	O
contrast	O
it	O
with	O
data	B-General_Concept
mart	I-General_Concept
,	O
which	O
is	O
a	O
smaller	O
repository	O
of	O
interesting	O
attributes	O
derived	O
from	O
raw	O
data	O
.	O
</s>
<s>
In	O
promoting	O
data	B-General_Concept
lakes	I-General_Concept
,	O
he	O
argued	O
that	O
data	B-General_Concept
marts	I-General_Concept
have	O
several	O
inherent	O
problems	O
,	O
such	O
as	O
information	O
siloing	O
.	O
</s>
<s>
PricewaterhouseCoopers	O
(	O
PwC	O
)	O
said	O
that	O
data	B-General_Concept
lakes	I-General_Concept
could	O
"	O
put	O
an	O
end	O
to	O
data	B-Application
silos	I-Application
"	O
.	O
</s>
<s>
In	O
their	O
study	O
on	O
data	B-General_Concept
lakes	I-General_Concept
they	O
noted	O
that	O
enterprises	O
were	O
"	O
starting	O
to	O
extract	O
and	O
place	O
data	O
for	O
analytics	O
into	O
a	O
single	O
,	O
Hadoop-based	O
repository.	O
"	O
</s>
<s>
Many	O
companies	O
use	O
cloud	B-Application
storage	I-Application
services	I-Application
such	O
as	O
Google	B-General_Concept
Cloud	I-General_Concept
Storage	I-General_Concept
and	O
Amazon	B-General_Concept
S3	I-General_Concept
or	O
a	O
distributed	O
file	O
system	O
such	O
as	O
Apache	B-Application
Hadoop	I-Application
distributed	O
file	O
system	O
(	O
HDFS	O
)	O
.	O
</s>
<s>
There	O
is	O
a	O
gradual	O
academic	O
interest	O
in	O
the	O
concept	O
of	O
data	B-General_Concept
lakes	I-General_Concept
.	O
</s>
<s>
For	O
example	O
,	O
Personal	O
DataLake	B-General_Concept
at	O
Cardiff	O
University	O
is	O
a	O
new	O
type	O
of	O
data	B-General_Concept
lake	I-General_Concept
which	O
aims	O
at	O
managing	O
big	B-Application
data	I-Application
of	O
individual	O
users	O
by	O
providing	O
a	O
single	O
point	O
of	O
collecting	O
,	O
organizing	O
,	O
and	O
sharing	O
personal	O
data	O
.	O
</s>
<s>
An	O
earlier	O
data	B-General_Concept
lake	I-General_Concept
(	O
Hadoop	B-Application
1.0	O
)	O
had	O
limited	O
capabilities	O
with	O
its	O
batch-oriented	O
processing	O
(	O
Map	B-Operating_System
Reduce	I-Operating_System
)	O
and	O
was	O
the	O
only	O
processing	O
paradigm	O
associated	O
with	O
it	O
.	O
</s>
<s>
Interacting	O
with	O
the	O
data	B-General_Concept
lake	I-General_Concept
meant	O
one	O
had	O
to	O
have	O
expertise	O
in	O
Java	O
with	O
map	B-Operating_System
reduce	I-Operating_System
and	O
higher-level	O
tools	O
like	O
Apache	B-Language
Pig	I-Language
,	O
Apache	B-Language
Spark	I-Language
and	O
Apache	B-General_Concept
Hive	I-General_Concept
(	O
which	O
by	O
themselves	O
were	O
originally	O
batch-oriented	O
)	O
.	O
</s>
<s>
Poorly-managed	O
data	B-General_Concept
lakes	I-General_Concept
have	O
been	O
facetiously	O
called	O
data	B-General_Concept
swamps	I-General_Concept
.	O
</s>
<s>
In	O
June	O
2015	O
,	O
David	O
Needle	O
characterized	O
"	O
so-called	O
data	B-General_Concept
lakes	I-General_Concept
"	O
as	O
"	O
one	O
of	O
the	O
more	O
controversial	O
ways	O
to	O
manage	O
big	B-Application
data	I-Application
"	O
.	O
</s>
<s>
PwC	O
was	O
also	O
careful	O
to	O
note	O
in	O
their	O
research	O
that	O
not	O
all	O
data	B-General_Concept
lake	I-General_Concept
initiatives	O
are	O
successful	O
.	O
</s>
<s>
They	O
describe	O
companies	O
that	O
build	O
successful	O
data	B-General_Concept
lakes	I-General_Concept
as	O
gradually	O
maturing	O
their	O
lake	O
as	O
they	O
figure	O
out	O
which	O
data	O
and	O
metadata	O
are	O
important	O
to	O
the	O
organization	O
.	O
</s>
<s>
Another	O
criticism	O
is	O
that	O
the	O
term	O
"	O
data	B-General_Concept
lake	I-General_Concept
"	O
is	O
not	O
useful	O
because	O
it	O
is	O
used	O
in	O
so	O
many	O
different	O
ways	O
.	O
</s>
<s>
While	O
critiques	O
of	O
data	B-General_Concept
lakes	I-General_Concept
are	O
warranted	O
,	O
in	O
many	O
cases	O
they	O
apply	O
to	O
other	O
data	O
projects	O
as	O
well	O
.	O
</s>
<s>
In	O
response	O
to	O
various	O
critiques	O
,	O
McKinsey	O
noted	O
that	O
the	O
data	B-General_Concept
lake	I-General_Concept
should	O
be	O
viewed	O
as	O
a	O
service	O
model	O
for	O
delivering	O
business	O
value	O
within	O
the	O
enterprise	O
,	O
not	O
a	O
technology	O
outcome	O
.	O
</s>
<s>
Data	O
lakehouse	O
is	O
a	O
proposed	O
hybrid	O
approach	O
of	O
a	O
data	B-General_Concept
lake	I-General_Concept
and	O
a	O
data	O
warehouse	O
,	O
and	O
attempts	O
to	O
solve	O
some	O
of	O
the	O
challenges	O
with	O
data	B-General_Concept
lakes	I-General_Concept
.	O
</s>
<s>
It	O
has	O
been	O
described	O
as	O
starting	O
with	O
a	O
"	O
data	B-General_Concept
lake	I-General_Concept
architecture	O
[	O
and	O
attempting ]	O
to	O
add	O
data	O
warehouse	O
capabilities	O
to	O
it	O
"	O
.	O
</s>
<s>
According	O
to	O
Oracle	O
,	O
it	O
combines	O
the	O
"	O
flexible	O
storage	O
of	O
unstructured	B-Application
data	I-Application
from	O
a	O
data	B-General_Concept
lake	I-General_Concept
and	O
the	O
management	O
features	O
and	O
tools	O
from	O
data	O
warehouses	O
"	O
.	O
</s>
