<s>
Percona	B-Language
XtraDB	I-Language
is	O
a	O
storage	B-General_Concept
engine	I-General_Concept
for	O
the	O
MariaDB	B-Application
and	O
Percona	B-Application
Server	I-Application
databases	O
,	O
and	O
is	O
intended	O
as	O
a	O
drop-in	O
replacement	O
to	O
InnoDB	B-Language
,	O
which	O
is	O
the	O
default	O
engine	O
in	O
MySQL	B-Application
.	O
</s>
<s>
Up	O
until	O
version	O
10.1	O
,	O
MariaDB	B-Application
used	O
Percona	B-Language
XtraDB	I-Language
in	O
place	O
of	O
InnoDB	B-Language
as	O
the	O
default	O
storage	B-General_Concept
engine	I-General_Concept
.	O
</s>
<s>
As	O
of	O
MariaDB	B-Application
10.2	O
,	O
InnoDB	B-Language
is	O
the	O
default	O
again	O
.	O
</s>
<s>
XtraDB	B-Language
incorporates	O
InnoDB	B-Language
's	O
ACID-compliant	O
design	O
and	O
MVCC	B-Operating_System
architecture	I-Operating_System
,	O
and	O
allows	O
for	O
a	O
greater	O
degree	O
of	O
tuning	O
and	O
scalability	O
.	O
</s>
<s>
The	O
engine	O
is	O
also	O
better	O
suited	O
to	O
multi-core	O
processing	O
,	O
which	O
addresses	O
some	O
of	O
the	O
issues	O
known	O
to	O
InnoDB	B-Language
.	O
</s>
