<s>
MySQL	B-Application
(	O
)	O
is	O
an	O
open-source	B-Application
relational	B-Application
database	I-Application
management	I-Application
system	I-Application
(	O
RDBMS	B-Application
)	O
.	O
</s>
<s>
Its	O
name	O
is	O
a	O
combination	O
of	O
"	O
My	O
"	O
,	O
the	O
name	O
of	O
co-founder	O
Michael	O
Widenius	O
's	O
daughter	O
My	O
,	O
and	O
"	O
SQL	B-Language
"	O
,	O
the	O
acronym	O
for	O
Structured	B-Language
Query	I-Language
Language	I-Language
.	O
</s>
<s>
A	O
relational	B-Application
database	I-Application
organizes	O
data	O
into	O
one	O
or	O
more	O
data	O
tables	O
in	O
which	O
data	O
may	O
be	O
related	O
to	O
each	O
other	O
;	O
these	O
relations	O
help	O
structure	O
the	O
data	O
.	O
</s>
<s>
SQL	B-Language
is	O
a	O
language	O
programmers	O
use	O
to	O
create	O
,	O
modify	O
and	O
extract	O
data	O
from	O
the	O
relational	B-Application
database	I-Application
,	O
as	O
well	O
as	O
control	O
user	O
access	O
to	O
the	O
database	O
.	O
</s>
<s>
In	O
addition	O
to	O
relational	B-Application
databases	I-Application
and	O
SQL	B-Language
,	O
an	O
RDBMS	B-Application
like	O
MySQL	B-Application
works	O
with	O
an	O
operating	B-General_Concept
system	I-General_Concept
to	O
implement	O
a	O
relational	B-Application
database	I-Application
in	O
a	O
computer	O
's	O
storage	O
system	O
,	O
manages	O
users	O
,	O
allows	O
for	O
network	O
access	O
and	O
facilitates	O
testing	O
database	O
integrity	O
and	O
creation	O
of	O
backups	O
.	O
</s>
<s>
MySQL	B-Application
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
under	O
the	O
terms	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
,	O
and	O
is	O
also	O
available	O
under	O
a	O
variety	O
of	O
proprietary	B-Application
licenses	I-Application
.	O
</s>
<s>
MySQL	B-Application
was	O
owned	O
and	O
sponsored	O
by	O
the	O
Swedish	O
company	O
MySQL	B-Application
AB	O
,	O
which	O
was	O
bought	O
by	O
Sun	O
Microsystems	O
(	O
now	O
Oracle	B-Application
Corporation	I-Application
)	O
.	O
</s>
<s>
In	O
2010	O
,	O
when	O
Oracle	B-Application
acquired	O
Sun	O
,	O
Widenius	O
forked	B-Application
the	O
open-source	B-Application
MySQL	B-Application
project	O
to	O
create	O
MariaDB	B-Application
.	O
</s>
<s>
MySQL	B-Application
has	O
stand-alone	O
clients	O
that	O
allow	O
users	O
to	O
interact	O
directly	O
with	O
a	O
MySQL	B-Application
database	O
using	O
SQL	B-Language
,	O
but	O
more	O
often	O
,	O
MySQL	B-Application
is	O
used	O
with	O
other	O
programs	O
to	O
implement	O
applications	O
that	O
need	O
relational	B-Application
database	I-Application
capability	O
.	O
</s>
<s>
MySQL	B-Application
is	O
a	O
component	O
of	O
the	O
LAMP	B-Application
web	B-Application
application	I-Application
software	B-Application
stack	I-Application
(	O
and	O
others	B-Application
)	O
,	O
which	O
is	O
an	O
acronym	O
for	O
Linux	B-Application
,	O
Apache	B-Application
,	O
MySQL	B-Application
,	O
Perl/PHP/Python	O
.	O
</s>
<s>
MySQL	B-Application
is	O
used	O
by	O
many	O
database-driven	O
web	B-Application
applications	I-Application
,	O
including	O
Drupal	B-Application
,	O
Joomla	B-Protocol
,	O
phpBB	B-Application
,	O
and	O
WordPress	B-Application
.	O
</s>
<s>
MySQL	B-Application
is	O
also	O
used	O
by	O
many	O
popular	O
websites	O
,	O
including	O
Facebook	B-Application
,	O
Flickr	B-Algorithm
,	O
MediaWiki	B-Application
,	O
Twitter	B-Application
,	O
and	O
YouTube	B-General_Concept
.	I-General_Concept
</s>
<s>
MySQL	B-Application
is	O
written	O
in	O
C	B-Language
and	O
C++	B-Language
.	O
</s>
<s>
Its	O
SQL	B-Language
parser	O
is	O
written	O
in	O
yacc	B-Application
,	O
but	O
it	O
uses	O
a	O
home-brewed	O
lexical	B-Application
analyzer	I-Application
.	O
</s>
<s>
MySQL	B-Application
works	O
on	O
many	O
system	B-Device
platforms	I-Device
,	O
including	O
AIX	B-Application
,	O
BSDi	B-Operating_System
,	O
FreeBSD	B-Operating_System
,	O
HP-UX	B-Application
,	O
ArcaOS	B-Device
,	O
eComStation	B-Device
,	O
IBM	B-Application
i	I-Application
,	O
IRIX	B-Operating_System
,	O
Linux	B-Application
,	O
macOS	B-Application
,	O
Microsoft	B-Application
Windows	I-Application
,	O
NetBSD	B-Device
,	O
Novell	B-Operating_System
NetWare	I-Operating_System
,	O
OpenBSD	B-Operating_System
,	O
OpenSolaris	B-Operating_System
,	O
OS/2	B-Application
Warp	O
,	O
QNX	B-Operating_System
,	O
Oracle	B-Application
Solaris	I-Application
,	O
Symbian	B-Operating_System
,	O
SunOS	B-Operating_System
,	O
SCO	B-Operating_System
OpenServer	I-Operating_System
,	O
SCO	B-Operating_System
UnixWare	I-Operating_System
,	O
Sanos	O
and	O
Tru64	B-Operating_System
.	O
</s>
<s>
A	O
port	O
of	O
MySQL	B-Application
to	O
OpenVMS	B-Operating_System
also	O
exists	O
.	O
</s>
<s>
The	O
MySQL	B-Application
server	I-Application
software	O
itself	O
and	O
the	O
client	O
libraries	B-Library
use	O
dual-licensing	B-License
distribution	O
.	O
</s>
<s>
They	O
are	O
offered	O
under	O
GPL	B-License
version	O
2	O
,	O
or	O
a	O
proprietary	B-Application
license	I-Application
.	O
</s>
<s>
Oracle	B-Application
offers	O
paid	O
support	O
via	O
its	O
MySQL	B-Language
Enterprise	I-Language
products	O
.	O
</s>
<s>
MySQL	B-Application
has	O
received	O
positive	O
reviews	O
,	O
and	O
reviewers	O
noticed	O
it	O
"	O
performs	O
extremely	O
well	O
in	O
the	O
average	O
case	O
"	O
and	O
that	O
the	O
"	O
developer	O
interfaces	O
are	O
there	O
,	O
and	O
the	O
documentation	O
(	O
not	O
to	O
mention	O
feedback	O
in	O
the	O
real	O
world	O
via	O
Web	O
sites	O
and	O
the	O
like	O
)	O
is	O
very	O
,	O
very	O
good	O
"	O
.	O
</s>
<s>
It	O
has	O
also	O
been	O
tested	O
to	O
be	O
a	O
"	O
fast	O
,	O
stable	O
and	O
true	O
multi-user	O
,	O
multi-threaded	O
SQL	B-Language
database	I-Language
server	O
"	O
.	O
</s>
<s>
MySQL	B-Application
was	O
created	O
by	O
a	O
Swedish	O
company	O
,	O
MySQL	B-Application
AB	O
,	O
founded	O
by	O
Swedes	O
David	O
Axmark	O
,	O
Allan	O
Larsson	O
and	O
Finland	O
Swede	O
Michael	O
"	O
Monty	O
"	O
Widenius	O
.	O
</s>
<s>
Original	O
development	O
of	O
MySQL	B-Application
by	O
Widenius	O
and	O
Axmark	O
began	O
in	O
1994	O
.	O
</s>
<s>
The	O
first	O
version	O
of	O
MySQL	B-Application
appeared	O
on	O
23	O
May	O
1995	O
.	O
</s>
<s>
It	O
was	O
initially	O
created	O
for	O
personal	O
usage	O
from	O
mSQL	B-Application
based	O
on	O
the	O
low-level	O
language	O
ISAM	B-Application
,	O
which	O
the	O
creators	O
considered	O
too	O
slow	O
and	O
inflexible	O
.	O
</s>
<s>
They	O
created	O
a	O
new	O
SQL	B-Language
interface	O
,	O
while	O
keeping	O
the	O
same	O
API	B-Application
as	O
mSQL	B-Application
.	O
</s>
<s>
By	O
keeping	O
the	O
API	B-Application
consistent	O
with	O
the	O
mSQL	B-Application
system	O
,	O
many	O
developers	O
were	O
able	O
to	O
use	O
MySQL	B-Application
instead	O
of	O
the	O
(	O
proprietarily	O
licensed	O
)	O
mSQL	B-Application
antecedent	O
.	O
</s>
<s>
Additional	O
milestones	O
in	O
MySQL	B-Application
development	O
included	O
:	O
</s>
<s>
Version	O
4.0	O
:	O
beta	O
from	O
August	O
2002	O
,	O
production	O
release	O
March	O
2003	O
(	O
unions	B-Language
)	O
.	O
</s>
<s>
Version	O
4.1	O
:	O
beta	O
from	O
June	O
2004	O
,	O
production	O
release	O
October	O
2004	O
(	O
R-trees	B-Library
and	O
B-trees	B-Architecture
,	O
subqueries	O
,	O
prepared	O
statements	O
)	O
.	O
</s>
<s>
Version	O
5.0	O
:	O
beta	O
from	O
March	O
2005	O
,	O
production	O
release	O
October	O
2005	O
(	O
cursors	B-Language
,	O
stored	B-General_Concept
procedures	I-General_Concept
,	O
triggers	B-Language
,	O
views	B-Language
,	O
XA	B-General_Concept
transactions	I-General_Concept
)	O
.	O
</s>
<s>
The	O
developer	O
of	O
the	O
Federated	B-Language
Storage	O
Engine	O
states	O
that	O
"	O
The	O
Federated	B-Language
Storage	O
Engine	O
is	O
a	O
proof-of-concept	O
storage	O
engine	O
"	O
,	O
but	O
the	O
main	O
distributions	O
of	O
MySQL	B-Application
version	O
5.0	O
included	O
it	O
and	O
turned	O
it	O
on	O
by	O
default	O
.	O
</s>
<s>
Documentation	O
of	O
some	O
of	O
the	O
short-comings	O
appears	O
in	O
"	O
MySQL	B-Language
Federated	I-Language
Tables	O
:	O
The	O
Missing	O
Manual	O
"	O
.	O
</s>
<s>
Sun	O
Microsystems	O
acquired	O
MySQL	B-Application
AB	O
in	O
2008	O
.	O
</s>
<s>
MySQL	B-Application
5.1	I-Application
and	O
6.0-alpha	O
showed	O
poor	O
performance	O
when	O
used	O
for	O
data	O
warehousing	O
partly	O
due	O
to	O
its	O
inability	O
to	O
utilize	O
multiple	O
CPU	O
cores	O
for	O
processing	O
a	O
single	O
query	O
.	O
</s>
<s>
Oracle	B-Application
acquired	O
Sun	O
Microsystems	O
on	O
27	O
January	O
2010	O
.	O
</s>
<s>
The	O
day	O
Oracle	B-Application
announced	O
the	O
purchase	O
of	O
Sun	O
,	O
Michael	O
"	O
Monty	O
"	O
Widenius	O
forked	B-Application
MySQL	B-Application
,	O
launching	O
MariaDB	B-Application
,	O
and	O
took	O
a	O
swath	O
of	O
MySQL	B-Application
developers	O
with	O
him	O
.	O
</s>
<s>
MySQL	B-Application
Server	I-Application
5.5	O
was	O
generally	O
available	O
(	O
)	O
.	O
</s>
<s>
The	O
default	O
storage	O
engine	O
is	O
InnoDB	B-Language
,	O
which	O
supports	O
transactions	O
and	O
referential	O
integrity	O
constraints	O
.	O
</s>
<s>
Semisynchronous	O
replication	B-General_Concept
.	O
</s>
<s>
SIGNAL	O
and	O
RESIGNAL	O
statement	O
in	O
compliance	O
with	O
the	O
SQL	B-Language
standard	O
.	O
</s>
<s>
New	O
options	O
for	O
user-defined	O
partitioning	B-General_Concept
.	O
</s>
<s>
MySQL	B-Application
Server	I-Application
6.0.11-alpha	O
was	O
announced	O
on	O
22	O
May	O
2009	O
as	O
the	O
last	O
release	O
of	O
the	O
6.0	O
line	O
.	O
</s>
<s>
Future	O
MySQL	B-Application
Server	I-Application
development	O
uses	O
a	O
New	O
Release	O
Model	O
.	O
</s>
<s>
New	O
features	O
included	O
performance	O
improvements	O
to	O
the	O
query	B-Language
optimizer	I-Language
,	O
higher	O
transactional	O
throughput	O
in	O
InnoDB	B-Language
,	O
new	O
NoSQL-style	O
memcached	B-Application
APIs	B-Application
,	O
improvements	O
to	O
partitioning	B-General_Concept
for	O
querying	O
and	O
managing	O
very	O
large	O
tables	O
,	O
column	O
type	O
that	O
correctly	O
stores	O
milliseconds	O
,	O
improvements	O
to	O
replication	B-General_Concept
,	O
and	O
better	O
performance	O
monitoring	O
by	O
expanding	O
the	O
data	O
available	O
through	O
the	O
.	O
</s>
<s>
The	O
InnoDB	B-Language
storage	I-Language
engine	I-Language
also	O
included	O
support	O
for	O
full-text	O
search	O
and	O
improved	O
group	O
commit	O
performance	O
.	O
</s>
<s>
As	O
of	O
MySQL	B-Application
5.7.8	O
,	O
August	O
2015	O
,	O
MySQL	B-Application
supports	O
a	O
native	O
JSON	B-General_Concept
data	O
type	O
defined	O
by	O
RFC	O
7159	O
.	O
</s>
<s>
MySQL	B-Application
Server	I-Application
8.0	O
was	O
announced	O
in	O
April	O
2018	O
,	O
including	O
NoSQL	B-General_Concept
Document	O
Store	O
,	O
atomic	O
and	O
crash	O
safe	O
DDL	O
sentences	O
and	O
JSON	B-General_Concept
Extended	O
syntax	O
,	O
new	O
functions	O
,	O
such	O
as	O
JSON	B-General_Concept
table	O
functions	O
,	O
improved	O
sorting	O
,	O
and	O
partial	O
updates	O
.	O
</s>
<s>
Previous	O
MySQL	B-Application
Server	I-Application
8.0.0-dmr	O
(	O
Milestone	O
Release	O
)	O
was	O
announced	O
12	O
September	O
2016	O
.	O
</s>
<s>
The	O
MySQL	B-Operating_System
Cluster	I-Operating_System
product	O
uses	O
version	O
7	O
.	O
</s>
<s>
On	O
15	O
June	O
2001	O
,	O
NuSphere	O
sued	O
MySQL	B-Application
AB	O
,	O
TcX	O
DataKonsult	O
AB	O
and	O
its	O
original	O
authors	O
Michael	O
(	O
"	O
Monty	O
"	O
)	O
Widenius	O
and	O
David	O
Axmark	O
in	O
U.S	O
District	O
Court	O
in	O
Boston	O
for	O
"	O
breach	O
of	O
contract	O
,	O
tortious	O
interference	O
with	O
third	O
party	O
contracts	O
and	O
relationships	O
and	O
unfair	O
competition	O
"	O
.	O
</s>
<s>
In	O
2002	O
,	O
MySQL	B-Application
AB	O
sued	O
Progress	O
NuSphere	O
for	O
copyright	O
and	O
trademark	O
infringement	O
in	O
United	O
States	O
district	O
court	O
.	O
</s>
<s>
NuSphere	O
had	O
allegedly	O
violated	O
MySQL	B-Application
AB	O
's	O
copyright	O
by	O
linking	O
MySQL	B-Application
's	O
GPL'ed	O
code	O
with	O
NuSphere	O
Gemini	O
table	O
without	O
being	O
in	O
compliance	O
with	O
the	O
license	O
.	O
</s>
<s>
After	O
the	O
hearing	O
,	O
FSF	B-Operating_System
commented	O
that	O
"	O
Judge	O
Saris	O
made	O
clear	O
that	O
she	O
sees	O
the	O
GNU	B-License
GPL	I-License
to	O
be	O
an	O
enforceable	O
and	O
binding	O
license.	O
"	O
</s>
<s>
In	O
October	O
2005	O
,	O
Oracle	B-Application
Corporation	I-Application
acquired	O
Innobase	B-Language
OY	I-Language
,	O
the	O
Finnish	O
company	O
that	O
developed	O
the	O
third-party	O
InnoDB	B-Language
storage	I-Language
engine	I-Language
that	O
allows	O
MySQL	B-Application
to	O
provide	O
such	O
functionality	O
as	O
transactions	O
and	O
foreign	B-Application
keys	I-Application
.	O
</s>
<s>
After	O
the	O
acquisition	O
,	O
an	O
Oracle	B-Application
press	O
release	O
mentioned	O
that	O
the	O
contracts	O
that	O
make	O
the	O
company	O
's	O
software	O
available	O
to	O
MySQL	B-Application
AB	O
would	O
be	O
due	O
for	O
renewal	O
(	O
and	O
presumably	O
renegotiation	O
)	O
some	O
time	O
in	O
2006	O
.	O
</s>
<s>
During	O
the	O
MySQL	B-Application
Users	O
Conference	O
in	O
April	O
2006	O
,	O
MySQL	B-Application
AB	O
issued	O
a	O
press	O
release	O
that	O
confirmed	O
that	O
MySQL	B-Application
AB	O
and	O
Innobase	B-Language
OY	I-Language
agreed	O
to	O
a	O
"	O
multi-year	O
"	O
extension	O
of	O
their	O
licensing	O
agreement	O
.	O
</s>
<s>
In	O
February	O
2006	O
,	O
Oracle	B-Application
Corporation	I-Application
acquired	O
Sleepycat	O
Software	O
,	O
makers	O
of	O
the	O
Berkeley	B-Language
DB	I-Language
,	O
a	O
database	O
engine	O
providing	O
the	O
basis	O
for	O
another	O
MySQL	B-Application
storage	O
engine	O
.	O
</s>
<s>
This	O
had	O
little	O
effect	O
,	O
as	O
Berkeley	B-Language
DB	I-Language
was	O
not	O
widely	O
used	O
,	O
and	O
was	O
dropped	O
(	O
due	O
to	O
lack	O
of	O
use	O
)	O
in	O
MySQL	O
5.1.12	O
,	O
a	O
pre-GA	O
release	O
of	O
MySQL	B-Application
5.1	I-Application
released	O
in	O
October	O
2006	O
.	O
</s>
<s>
In	O
January	O
2008	O
,	O
Sun	O
Microsystems	O
bought	O
MySQL	B-Application
AB	O
for	O
$1	O
billion	O
.	O
</s>
<s>
In	O
April	O
2009	O
,	O
Oracle	B-Application
Corporation	I-Application
entered	O
into	O
an	O
agreement	O
to	O
purchase	O
Sun	O
Microsystems	O
,	O
then	O
owners	O
of	O
MySQL	B-Application
copyright	O
and	O
trademark	O
.	O
</s>
<s>
On	O
14	O
December	O
2009	O
,	O
Oracle	B-Application
pledged	O
to	O
continue	O
to	O
enhance	O
MySQL	B-Application
as	O
it	O
had	O
done	O
for	O
the	O
previous	O
four	O
years	O
.	O
</s>
<s>
A	O
movement	O
against	O
Oracle	B-Application
's	O
acquisition	O
of	O
MySQL	B-Application
AB	O
,	O
to	O
"	O
Save	O
MySQL	B-Application
"	O
from	O
Oracle	B-Application
was	O
started	O
by	O
one	O
of	O
the	O
MySQL	B-Application
AB	O
founders	O
,	O
Monty	O
Widenius	O
.	O
</s>
<s>
At	O
the	O
same	O
time	O
,	O
some	O
Free	B-Application
Software	I-Application
opinion	O
leaders	O
(	O
including	O
Pamela	O
Jones	O
of	O
Groklaw	B-Application
,	O
Jan	O
Wildeboer	O
and	O
Carlo	O
Piana	O
,	O
who	O
also	O
acted	O
as	O
co-counsel	O
in	O
the	O
merger	O
regulation	O
procedure	O
)	O
advocated	O
for	O
the	O
unconditional	O
approval	O
of	O
the	O
merger	O
.	O
</s>
<s>
As	O
part	O
of	O
the	O
negotiations	O
with	O
the	O
European	O
Commission	O
,	O
Oracle	B-Application
committed	O
that	O
MySQL	B-Application
server	I-Application
will	O
continue	O
until	O
at	O
least	O
2015	O
to	O
use	O
the	O
dual-licensing	B-License
strategy	O
long	O
used	O
by	O
MySQL	B-Application
AB	O
,	O
with	O
proprietary	B-Application
and	O
GPL	B-License
versions	O
available	O
.	O
</s>
<s>
The	O
antitrust	O
of	O
the	O
EU	O
had	O
been	O
"	O
pressuring	O
it	O
to	O
divest	O
MySQL	B-Application
as	O
a	O
condition	O
for	O
approval	O
of	O
the	O
merger	O
"	O
.	O
</s>
<s>
But	O
,	O
as	O
revealed	O
by	O
WikiLeaks	O
,	O
the	O
US	O
Department	O
of	O
Justice	O
,	O
at	O
the	O
request	O
of	O
Oracle	B-Application
,	O
pressured	O
the	O
EU	O
to	O
approve	O
the	O
merger	O
unconditionally	O
.	O
</s>
<s>
The	O
European	O
Commission	O
eventually	O
unconditionally	O
approved	O
Oracle	B-Application
's	O
acquisition	O
of	O
MySQL	B-Application
AB	O
on	O
21	O
January	O
2010	O
.	O
</s>
<s>
In	O
January	O
2010	O
,	O
before	O
Oracle	B-Application
's	O
acquisition	O
of	O
MySQL	B-Application
AB	O
,	O
Monty	O
Widenius	O
started	O
a	O
GPL-only	O
fork	B-Application
,	O
MariaDB	B-Application
.	O
</s>
<s>
MariaDB	B-Application
is	O
based	O
on	O
the	O
same	O
code	O
base	O
as	O
MySQL	B-Application
server	I-Application
5.5	O
and	O
aims	O
to	O
maintain	O
compatibility	O
with	O
Oracle-provided	O
versions	O
.	O
</s>
<s>
MySQL	B-Application
is	O
offered	O
under	O
two	O
different	O
editions	O
:	O
the	O
open	B-Application
source	I-Application
MySQL	B-Application
Community	O
Server	O
and	O
the	O
proprietary	B-Application
Enterprise	B-Language
Server	I-Language
.	O
</s>
<s>
MySQL	B-Language
Enterprise	I-Language
Server	O
is	O
differentiated	O
by	O
a	O
series	O
of	O
proprietary	B-Application
extensions	O
which	O
install	O
as	O
server	O
plugins	O
,	O
but	O
otherwise	O
shares	O
the	O
version	O
numbering	O
system	O
and	O
is	O
built	O
from	O
the	O
same	O
code	O
base	O
.	O
</s>
<s>
Online	O
Data	B-Language
Definition	I-Language
Language	I-Language
(	O
DDL	O
)	O
when	O
using	O
the	O
InnoDB	B-Language
Storage	I-Language
Engine	I-Language
.	O
</s>
<s>
A	O
set	O
of	O
SQL	B-Language
Mode	O
options	O
to	O
control	O
runtime	B-Library
behavior	O
,	O
including	O
a	O
strict	O
mode	O
to	O
better	O
adhere	O
to	O
SQL	B-Language
standards	O
.	O
</s>
<s>
Transactions	O
with	O
savepoints	B-General_Concept
when	O
using	O
the	O
default	O
InnoDB	B-Language
Storage	I-Language
Engine	I-Language
.	O
</s>
<s>
Sub-SELECTs	O
(	O
i.e.	O
</s>
<s>
Synchronous	O
replication	B-General_Concept
:	O
Multi-master	B-Operating_System
replication	I-Operating_System
is	O
provided	O
in	O
MySQL	B-Operating_System
Cluster	I-Operating_System
.	O
</s>
<s>
Native	O
storage	O
engines	O
InnoDB	B-Language
,	O
MyISAM	B-Language
,	O
Merge	O
,	O
Memory	O
(	O
heap	O
)	O
,	O
Federated	B-Language
,	O
Archive	O
,	O
CSV	O
,	O
Blackhole	O
,	O
NDB	O
Cluster	O
.	O
</s>
<s>
The	O
developers	O
release	O
minor	O
updates	O
of	O
the	O
MySQL	B-Application
Server	I-Application
approximately	O
every	O
two	O
months	O
.	O
</s>
<s>
The	O
sources	O
can	O
be	O
obtained	O
from	O
MySQL	B-Application
's	O
website	O
or	O
from	O
MySQL	B-Application
's	O
GitHub	B-Application
repository	O
,	O
both	O
under	O
the	O
GPL	B-License
license	I-License
.	O
</s>
<s>
When	O
using	O
some	O
storage	O
engines	O
other	O
than	O
the	O
default	O
of	O
InnoDB	B-Language
,	O
MySQL	B-Application
does	O
not	O
comply	O
with	O
the	O
full	O
SQL	B-Language
standard	O
for	O
some	O
of	O
the	O
implemented	O
functionality	O
,	O
including	O
foreign	B-Application
key	I-Application
references	O
.	O
</s>
<s>
Check	O
constraints	O
are	O
parsed	O
but	O
ignored	O
by	O
all	O
storage	O
engines	O
before	O
MySQL	B-Application
version	O
8.0.15	O
.	O
</s>
<s>
Up	O
until	O
MySQL	O
5.7	O
,	O
triggers	B-Language
are	O
limited	O
to	O
one	O
per	O
action	O
/	O
timing	O
,	O
meaning	O
that	O
at	O
most	O
one	O
trigger	O
can	O
be	O
defined	O
to	O
be	O
executed	O
after	O
an	O
operation	O
,	O
and	O
one	O
before	O
on	O
the	O
same	O
table	O
.	O
</s>
<s>
No	O
triggers	B-Language
can	O
be	O
defined	O
on	O
views	B-Language
.	O
</s>
<s>
MySQL	B-Application
database	O
's	O
inbuilt	O
functions	O
like	O
will	O
return	O
after	O
03:14:07	O
UTC	O
on	O
19	B-Application
January	I-Application
2038	I-Application
.	O
</s>
<s>
MySQL	B-Application
can	O
be	O
built	O
and	O
installed	O
manually	O
from	O
source	O
code	O
,	O
but	O
it	O
is	O
more	O
commonly	O
installed	O
from	O
a	O
binary	O
package	O
unless	O
special	O
customizations	O
are	O
required	O
.	O
</s>
<s>
On	O
most	O
Linux	B-Application
distributions	I-Application
,	O
the	O
package	B-Application
management	I-Application
system	I-Application
can	O
download	O
and	O
install	O
MySQL	B-Application
with	O
minimal	O
effort	O
,	O
though	O
further	O
configuration	O
is	O
often	O
required	O
to	O
adjust	O
security	O
and	O
optimization	O
settings	O
.	O
</s>
<s>
Though	O
MySQL	B-Application
began	O
as	O
a	O
low-end	O
alternative	O
to	O
more	O
powerful	O
proprietary	B-Application
databases	O
,	O
it	O
has	O
gradually	O
evolved	O
to	O
support	O
higher-scale	O
needs	O
as	O
well	O
.	O
</s>
<s>
It	O
is	O
still	O
most	O
commonly	O
used	O
in	O
small	O
to	O
medium	O
scale	O
single-server	O
deployments	O
,	O
either	O
as	O
a	O
component	O
in	O
a	O
LAMP-based	O
web	B-Application
application	I-Application
or	O
as	O
a	O
standalone	O
database	O
server	O
.	O
</s>
<s>
Much	O
of	O
MySQL	B-Application
's	O
appeal	O
originates	O
in	O
its	O
relative	O
simplicity	O
and	O
ease	O
of	O
use	O
,	O
which	O
is	O
enabled	O
by	O
an	O
ecosystem	O
of	O
open	B-Application
source	I-Application
tools	O
such	O
as	O
phpMyAdmin	B-Application
.	O
</s>
<s>
In	O
the	O
medium	O
range	O
,	O
MySQL	B-Application
can	O
be	O
scaled	O
by	O
deploying	O
it	O
on	O
more	O
powerful	O
hardware	O
,	O
such	O
as	O
a	O
multi-processor	O
server	O
with	O
gigabytes	O
of	O
memory	O
.	O
</s>
<s>
There	O
are	O
,	O
however	O
,	O
limits	O
to	O
how	O
far	O
performance	O
can	O
scale	O
on	O
a	O
single	O
server	O
( 	O
 '	O
scaling	O
up	O
 '	O
)	O
,	O
so	O
on	O
larger	O
scales	O
,	O
multi-server	O
MySQL	B-Application
( 	O
 '	O
scaling	O
out	O
 '	O
)	O
deployments	O
are	O
required	O
to	O
provide	O
improved	O
performance	O
and	O
reliability	O
.	O
</s>
<s>
A	O
typical	O
high-end	O
configuration	O
can	O
include	O
a	O
powerful	O
master	O
database	O
which	O
handles	O
data	O
write	O
operations	O
and	O
is	O
replicated	B-General_Concept
to	O
multiple	O
slaves	O
that	O
handle	O
all	O
read	O
operations	O
.	O
</s>
<s>
Further	O
improvements	O
in	O
performance	O
can	O
be	O
achieved	O
by	O
caching	B-General_Concept
the	O
results	O
from	O
database	O
queries	O
in	O
memory	O
using	O
memcached	B-Application
,	O
or	O
breaking	O
down	O
a	O
database	O
into	O
smaller	O
chunks	O
called	O
shards	B-General_Concept
which	O
can	O
be	O
spread	O
across	O
a	O
number	O
of	O
distributed	O
server	O
clusters	O
.	O
</s>
<s>
Oracle	B-Application
MySQL	B-Application
offers	O
a	O
high	O
availability	O
solution	O
with	O
a	O
mix	O
of	O
tools	O
including	O
the	O
MySQL	B-Application
router	O
and	O
the	O
MySQL	B-Application
shell	O
.	O
</s>
<s>
They	O
are	O
based	O
on	O
Group	O
Replication	B-General_Concept
,	O
open	B-Application
source	I-Application
tools	O
.	O
</s>
<s>
MariaDB	B-Application
offers	O
a	O
similar	O
offer	O
in	O
terms	O
of	O
products	O
.	O
</s>
<s>
MySQL	B-Application
can	O
also	O
be	O
run	O
on	O
cloud	B-Architecture
computing	I-Architecture
platforms	I-Architecture
such	O
as	O
Microsoft	B-Application
Azure	I-Application
,	O
Amazon	B-General_Concept
Elastic	I-General_Concept
Compute	I-General_Concept
Cloud	I-General_Concept
,	O
.	O
</s>
<s>
Some	O
common	O
deployment	O
models	O
for	O
MySQL	B-Application
on	O
the	O
cloud	O
are	O
:	O
</s>
<s>
In	O
this	O
implementation	O
,	O
cloud	B-Architecture
users	I-Architecture
can	O
upload	O
a	O
machine	O
image	O
of	O
their	O
own	O
with	O
MySQL	B-Application
installed	O
,	O
or	O
use	O
a	O
ready-made	O
machine	O
image	O
with	O
an	O
optimized	O
installation	O
of	O
MySQL	B-Application
on	O
it	O
,	O
such	O
as	O
the	O
one	O
provided	O
by	O
Amazon	B-General_Concept
EC2	I-General_Concept
.	O
</s>
<s>
Some	O
cloud	O
platforms	B-Device
offer	O
MySQL	B-Application
"	O
as	O
a	O
service	O
"	O
.	O
</s>
<s>
In	O
this	O
configuration	O
,	O
application	O
owners	O
do	O
not	O
have	O
to	O
install	O
and	O
maintain	O
the	O
MySQL	B-Application
database	O
on	O
their	O
own	O
.	O
</s>
<s>
Notable	O
cloud-based	B-Architecture
MySQL	B-Application
services	O
are	O
the	O
Amazon	O
Relational	B-Application
Database	I-Application
Service	O
;	O
,	O
,	O
Rackspace	O
;	O
HP	B-General_Concept
Converged	I-General_Concept
Cloud	I-General_Concept
;	O
Heroku	B-General_Concept
and	O
Jelastic	B-General_Concept
.	O
</s>
<s>
A	O
graphical	B-Application
user	I-Application
interface	I-Application
(	O
GUI	B-Application
)	O
is	O
a	O
type	O
of	O
interface	O
that	O
allows	O
users	O
to	O
interact	O
with	O
electronic	O
devices	O
or	O
programs	O
through	O
graphical	O
icons	O
and	O
visual	O
indicators	O
such	O
as	O
secondary	O
notation	O
,	O
as	O
opposed	O
to	O
text-based	O
interfaces	O
,	O
typed	O
command	O
labels	O
or	O
text	O
navigation	O
.	O
</s>
<s>
Third-party	O
proprietary	B-Application
and	O
free	O
graphical	O
administration	O
applications	O
(	O
or	O
"	O
front	O
ends	O
"	O
)	O
are	O
available	O
that	O
integrate	O
with	O
MySQL	B-Application
and	O
enable	O
users	O
to	O
work	O
with	O
database	O
structure	O
and	O
data	O
visually	O
.	O
</s>
<s>
MySQL	B-Language
Workbench	I-Language
is	O
the	O
integrated	O
environment	O
for	O
MySQL	B-Application
.	O
</s>
<s>
It	O
was	O
developed	O
by	O
MySQL	B-Application
AB	O
,	O
and	O
enables	O
users	O
to	O
graphically	O
administer	O
MySQL	B-Application
databases	O
and	O
visually	O
design	O
database	O
structures	O
.	O
</s>
<s>
MySQL	B-Language
Workbench	I-Language
is	O
available	O
in	O
three	O
editions	O
,	O
the	O
regular	O
free	B-Application
and	I-Application
open	I-Application
source	I-Application
Community	O
Edition	O
which	O
may	O
be	O
downloaded	O
from	O
the	O
MySQL	B-Application
website	O
,	O
and	O
the	O
proprietary	B-Application
Standard	O
Edition	O
which	O
extends	O
and	O
improves	O
the	O
feature	O
set	O
of	O
the	O
Community	O
Edition	O
,	O
and	O
the	O
MySQL	B-Operating_System
Cluster	I-Operating_System
CGE	O
.	O
</s>
<s>
A	O
command-line	B-Application
interface	I-Application
is	O
a	O
means	O
of	O
interacting	O
with	O
a	O
computer	O
program	O
where	O
the	O
user	O
issues	O
commands	O
to	O
the	O
program	O
by	O
typing	O
in	O
successive	O
lines	O
of	O
text	O
(	O
command	B-Application
lines	I-Application
)	O
.	O
</s>
<s>
MySQL	B-Application
ships	O
with	O
many	O
command	B-Application
line	I-Application
tools	I-Application
,	O
from	O
which	O
the	O
main	O
interface	O
is	O
the	O
client	O
.	O
</s>
<s>
MySQL	B-Application
Utilities	O
is	O
a	O
set	O
of	O
utilities	O
designed	O
to	O
perform	O
common	O
maintenance	O
and	O
administrative	O
tasks	O
.	O
</s>
<s>
Originally	O
included	O
as	O
part	O
of	O
the	O
MySQL	B-Language
Workbench	I-Language
,	O
the	O
utilities	O
are	O
a	O
stand-alone	O
download	O
available	O
from	O
Oracle	B-Application
.	O
</s>
<s>
Percona	B-Language
Toolkit	I-Language
is	O
a	O
cross-platform	O
toolkit	O
for	O
MySQL	B-Application
,	O
developed	O
in	O
Perl	B-Language
.	O
</s>
<s>
Percona	B-Language
Toolkit	I-Language
can	O
be	O
used	O
to	O
prove	O
replication	B-General_Concept
is	O
working	O
correctly	O
,	O
fix	O
corrupted	O
data	O
,	O
automate	O
repetitive	O
tasks	O
,	O
and	O
speed	O
up	O
servers	O
.	O
</s>
<s>
Percona	B-Language
Toolkit	I-Language
is	O
included	O
with	O
several	O
Linux	B-Application
distributions	I-Application
such	O
as	O
CentOS	O
and	O
Debian	O
,	O
and	O
packages	O
are	O
available	O
for	O
Fedora	O
and	O
Ubuntu	B-Operating_System
as	O
well	O
.	O
</s>
<s>
Percona	B-Language
Toolkit	I-Language
was	O
originally	O
developed	O
as	O
Maatkit	O
,	O
but	O
as	O
of	O
late	O
2011	O
,	O
Maatkit	O
is	O
no	O
longer	O
developed	O
.	O
</s>
<s>
MySQL	B-Application
shell	O
is	O
a	O
tool	O
for	O
interactive	O
use	O
and	O
administration	O
of	O
the	O
MySQL	B-Application
database	O
.	O
</s>
<s>
It	O
supports	O
JavaScript	O
,	O
Python	B-Language
or	O
SQL	B-Language
modes	O
and	O
it	O
can	O
be	O
used	O
for	O
administration	O
and	O
access	O
purposes	O
.	O
</s>
<s>
Many	O
programming	O
languages	O
with	O
language-specific	O
APIs	B-Application
include	O
libraries	B-Library
for	O
accessing	O
MySQL	B-Application
databases	O
.	O
</s>
<s>
These	O
include	O
MySQL	B-Application
Connector/Net	O
for	O
.NET/CLI	B-Language
Languages	I-Language
,	O
and	O
the	O
JDBC	O
driver	O
for	O
Java	O
.	O
</s>
<s>
In	O
addition	O
,	O
an	O
ODBC	B-Application
interface	O
called	O
MySQL	B-General_Concept
Connector/ODBC	I-General_Concept
allows	O
additional	O
programming	O
languages	O
that	O
support	O
the	O
ODBC	B-Application
interface	O
to	O
communicate	O
with	O
a	O
MySQL	B-Application
database	O
,	O
such	O
as	O
ASP	B-General_Concept
or	O
ColdFusion	B-Language
.	O
</s>
<s>
The	O
HTSQL	B-Language
URL-based	O
query	O
method	O
also	O
ships	O
with	O
a	O
MySQL	B-Application
adapter	O
,	O
allowing	O
direct	O
interaction	O
between	O
a	O
MySQL	B-Application
database	O
and	O
any	O
web	O
client	O
via	O
structured	O
URLs	O
.	O
</s>
<s>
Other	O
drivers	O
exists	O
for	O
languages	O
like	O
Python	B-Language
or	O
Node.js	B-Language
.	O
</s>
<s>
A	O
variety	O
of	O
MySQL	B-Application
forks	B-Application
exist	O
,	O
including	O
the	O
following	O
.	O
</s>
<s>
MariaDB	B-Application
is	O
a	O
community-developed	O
fork	B-Application
of	O
the	O
MySQL	B-Application
relational	B-Application
database	I-Application
management	I-Application
system	I-Application
intended	O
to	O
remain	O
free	O
under	O
the	O
GNU	B-License
GPL	I-License
.	O
</s>
<s>
The	O
fork	B-Application
has	O
been	O
led	O
by	O
the	O
original	O
developers	O
of	O
MySQL	B-Application
,	O
who	O
forked	B-Application
it	O
due	O
to	O
concerns	O
over	O
its	O
acquisition	O
by	O
Oracle	B-Application
.	O
</s>
<s>
Percona	B-Application
Server	I-Application
for	I-Application
MySQL	I-Application
,	O
forked	B-Application
by	O
Percona	B-Language
,	O
aims	O
to	O
retain	O
close	O
compatibility	O
to	O
the	O
official	O
MySQL	B-Application
releases	O
.	O
</s>
<s>
Also	O
included	O
in	O
Percona	B-Application
Server	I-Application
for	I-Application
MySQL	I-Application
is	O
XtraDB	B-Language
,	O
Percona	B-Language
's	O
fork	B-Application
of	O
the	O
InnoDB	B-Language
Storage	I-Language
Engine	I-Language
.	O
</s>
<s>
Drizzle	B-Application
was	O
a	O
free	O
software/open	O
source	O
relational	B-Application
database	I-Application
management	I-Application
system	I-Application
(	O
DBMS	O
)	O
that	O
was	O
forked	B-Application
from	O
the	O
now-defunct	O
6.0	O
development	O
branch	O
of	O
the	O
MySQL	B-Application
DBMS	O
.	O
</s>
<s>
Like	O
MySQL	B-Application
,	O
Drizzle	B-Application
had	O
a	O
client/server	B-Operating_System
architecture	I-Operating_System
and	O
uses	O
SQL	B-Language
as	O
its	O
primary	O
command	B-Language
language	I-Language
.	O
</s>
<s>
Drizzle	B-Application
was	O
distributed	O
under	O
version	O
2	O
and	O
3	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
(	O
GPL	B-License
)	O
with	O
portions	O
,	O
including	O
the	O
protocol	O
drivers	O
and	O
replication	B-General_Concept
messaging	O
under	O
the	O
BSD	B-Operating_System
license	I-Operating_System
.	O
</s>
<s>
WebScaleSQL	B-Application
was	O
a	O
software	O
branch	O
of	O
MySQL	B-Application
5.6	O
,	O
and	O
was	O
announced	O
on	O
27	O
March	O
2014	O
by	O
Facebook	B-Application
,	O
Google	O
,	O
LinkedIn	O
and	O
Twitter	B-Application
as	O
a	O
joint	O
effort	O
to	O
provide	O
a	O
centralized	O
development	O
structure	O
for	O
extending	O
MySQL	B-Application
with	O
new	O
features	O
specific	O
to	O
its	O
large-scale	O
deployments	O
,	O
such	O
as	O
building	O
large	O
replicated	B-General_Concept
databases	O
running	O
on	O
server	O
farms	O
.	O
</s>
<s>
Thus	O
,	O
WebScaleSQL	B-Application
opened	O
a	O
path	O
toward	O
deduplicating	O
the	O
efforts	O
each	O
company	O
had	O
been	O
putting	O
into	O
maintaining	O
its	O
own	O
branch	O
of	O
MySQL	B-Application
,	O
and	O
toward	O
bringing	O
together	O
more	O
developers	O
.	O
</s>
<s>
By	O
combining	O
the	O
efforts	O
of	O
these	O
companies	O
and	O
incorporating	O
various	O
changes	O
and	O
new	O
features	O
into	O
MySQL	B-Application
,	O
WebScaleSQL	B-Application
aimed	O
at	O
supporting	O
the	O
deployment	O
of	O
MySQL	B-Application
in	O
large-scale	O
environments	O
.	O
</s>
<s>
The	O
project	O
's	O
source	O
code	O
is	O
licensed	O
under	O
version	O
2	O
of	O
the	O
GNU	B-License
General	I-License
Public	I-License
License	I-License
,	O
and	O
is	O
hosted	O
on	O
GitHub	B-Application
.	O
</s>
<s>
The	O
OurDelta	O
distribution	O
,	O
created	O
by	O
the	O
Australian	O
company	O
Open	O
Query	O
(	O
later	O
acquired	O
by	O
Catalyst	O
IT	O
Australia	O
)	O
,	O
had	O
two	O
versions	O
:	O
5.0	O
,	O
which	O
was	O
based	O
on	O
MySQL	B-Application
,	O
and	O
5.1	O
,	O
which	O
was	O
based	O
on	O
MariaDB	B-Application
.	O
</s>
<s>
It	O
included	O
patches	O
developed	O
by	O
Open	O
Query	O
and	O
by	O
other	O
notable	O
members	O
of	O
the	O
MySQL	B-Application
community	O
including	O
Jeremy	O
Cole	O
and	O
Google	O
.	O
</s>
<s>
Once	O
the	O
patches	O
were	O
incorporated	O
into	O
the	O
MariaDB	B-Application
mainline	O
,	O
OurDelta	O
's	O
objectives	O
were	O
achieved	O
and	O
OurDelta	O
passed	O
on	O
its	O
build	O
and	O
packaging	O
toolchain	O
to	O
Monty	O
Program	O
(	O
now	O
MariaDB	B-Application
Corp	O
)	O
.	O
</s>
