<s>
TokuDB	B-Language
is	O
an	O
open-source	B-Application
,	O
high-performance	O
storage	B-General_Concept
engine	I-General_Concept
for	O
MySQL	B-Application
and	O
MariaDB	B-Application
.	O
</s>
<s>
It	O
achieves	O
this	O
by	O
using	O
a	O
fractal	B-Data_Structure
tree	I-Data_Structure
index	I-Data_Structure
.	O
</s>
<s>
It	O
is	O
scalable	O
,	O
ACID	O
and	O
MVCC	B-Operating_System
compliant	O
,	O
provides	O
indexing-based	O
query	O
improvements	O
,	O
offers	O
online	O
schema	B-Application
modifications	O
,	O
and	O
reduces	O
replication	O
lag	O
for	O
both	O
hard	B-Device
disk	I-Device
drives	I-Device
and	O
flash	B-Device
memory	I-Device
.	O
</s>
<s>
TokuDB	B-Language
is	O
included	O
in	O
Percona	B-Application
Server	I-Application
,	O
MariaDB	B-Application
and	O
Nagios	B-Application
based	O
opmon	O
.	O
</s>
<s>
However	O
,	O
it	O
is	O
deprecated	O
in	O
Percona	B-Application
Server	I-Application
8	O
and	O
MariaDB	B-Application
10.5	O
.	O
</s>
<s>
TokuDB	B-Language
uses	O
a	O
Fractal	B-Data_Structure
tree	I-Data_Structure
index	I-Data_Structure
tree	B-Application
data	I-Application
structure	I-Application
that	O
keeps	O
data	O
sorted	O
and	O
allows	O
searches	O
and	O
sequential	O
access	O
in	O
the	O
same	O
time	O
as	O
a	O
B-tree	B-Architecture
but	O
with	O
insertions	O
and	O
deletions	O
that	O
are	O
asymptotically	O
faster	O
than	O
a	O
B-tree	B-Architecture
.	O
</s>
<s>
Fractal	O
trees	O
also	O
allow	O
for	O
messages	O
to	O
be	O
injected	O
into	O
the	O
tree	O
in	O
such	O
a	O
fashion	O
that	O
schema	B-Application
changes	O
(	O
such	O
as	O
adding	O
or	O
dropping	O
a	O
column	B-Application
,	O
or	O
adding	O
an	O
index	O
)	O
can	O
be	O
done	O
online	O
and	O
in	O
the	O
background	O
.	O
</s>
<s>
This	O
is	O
because	O
adding	O
data	O
to	O
indexes	O
tends	O
to	O
stress	O
the	O
performance	O
of	O
B-trees	B-Architecture
,	O
but	O
performs	O
well	O
in	O
fractal	B-Data_Structure
tree	I-Data_Structure
indexes	I-Data_Structure
.	O
</s>
<s>
Fractal	B-Data_Structure
tree	I-Data_Structure
indexes	I-Data_Structure
can	O
be	O
applied	O
to	O
a	O
number	O
of	O
applications	O
characterized	O
by	O
near-real	O
time	O
analysis	O
of	O
streaming	O
data	O
.	O
</s>
<s>
When	O
used	O
in	O
a	O
database	O
,	O
they	O
can	O
be	O
used	O
in	O
any	O
setting	O
where	O
a	O
B-tree	B-Architecture
is	O
used	O
,	O
with	O
improved	O
performance	O
.	O
</s>
<s>
Other	O
uses	O
include	O
accelerated	O
crawler	B-Application
performance	O
for	O
search	B-Application
engines	I-Application
for	O
social	O
media	O
sites	O
.	O
</s>
<s>
In	O
general	O
,	O
it	O
performs	O
well	O
in	O
applications	O
that	O
must	O
simultaneously	O
store	O
log	B-Application
file	I-Application
data	O
and	O
execute	O
ad	O
hoc	O
queries	O
.	O
</s>
<s>
TokuDB	B-Language
is	O
named	O
as	O
one	O
of	O
the	O
technologies	O
that	O
enable	O
big	B-Application
data	I-Application
in	O
MySQL	B-Application
.	O
</s>
<s>
Tokutek	B-Language
was	O
a	O
Startup	O
Showcase	O
Finalist	O
at	O
the	O
O'Reilly	O
Strata	O
Conference	O
2012	O
on	O
big	B-Application
data	I-Application
.	O
</s>
