<s>
A	O
JDBC	B-Application
driver	I-Application
is	O
a	O
software	O
component	O
enabling	O
a	O
Java	B-Language
application	O
to	O
interact	O
with	O
a	O
database	O
.	O
</s>
<s>
JDBC	B-Application
drivers	I-Application
are	O
analogous	O
to	O
ODBC	B-Application
drivers	O
,	O
ADO.NET	B-Device
data	I-Device
providers	I-Device
,	O
and	O
OLE	B-Language
DB	I-Language
providers	I-Language
.	O
</s>
<s>
To	O
connect	O
with	O
individual	O
databases	O
,	O
JDBC	B-Language
(	O
the	O
Java	B-Language
Database	I-Language
Connectivity	I-Language
API	B-Application
)	O
requires	O
drivers	O
for	O
each	O
database	O
.	O
</s>
<s>
The	O
JDBC	B-Application
driver	I-Application
gives	O
out	O
the	O
connection	B-General_Concept
to	O
the	O
database	O
and	O
implements	O
the	O
protocol	O
for	O
transferring	O
the	O
query	O
and	O
result	O
between	O
client	B-Protocol
and	O
database	O
.	O
</s>
<s>
JDBC	B-Language
technology	O
drivers	O
fit	O
into	O
one	O
of	O
four	O
categories	O
.	O
</s>
<s>
Database-Protocol	O
driver	O
(	O
Pure	O
Java	B-Language
driver	O
)	O
or	O
thin	O
driver	O
.	O
</s>
<s>
The	O
JDBC	B-Language
type	O
1	O
driver	O
,	O
also	O
known	O
as	O
the	O
JDBC-ODBC	B-Application
bridge	I-Application
,	O
is	O
a	O
database	B-Application
driver	I-Application
implementation	O
that	O
employs	O
the	O
ODBC	B-Application
driver	O
to	O
connect	O
to	O
the	O
database	O
.	O
</s>
<s>
The	O
driver	O
converts	O
JDBC	B-Language
method	O
calls	O
into	O
ODBC	B-Application
function	O
calls	O
.	O
</s>
<s>
The	O
driver	O
is	O
platform-dependent	O
as	O
it	O
makes	O
use	O
of	O
ODBC	B-Application
which	O
in	O
turn	O
depends	O
on	O
native	O
libraries	O
of	O
the	O
underlying	O
operating	B-General_Concept
system	I-General_Concept
the	O
JVM	B-Language
is	O
running	O
upon	O
.	O
</s>
<s>
Also	O
,	O
use	O
of	O
this	O
driver	O
leads	O
to	O
other	O
installation	O
dependencies	O
;	O
for	O
example	O
,	O
ODBC	B-Application
must	O
be	O
installed	O
on	O
the	O
computer	O
having	O
the	O
driver	O
and	O
the	O
database	O
must	O
support	O
an	O
ODBC	B-Application
driver	O
.	O
</s>
<s>
The	O
use	O
of	O
this	O
driver	O
is	O
discouraged	O
if	O
the	O
alternative	O
of	O
a	O
pure-Java	O
driver	O
is	O
available	O
.	O
</s>
<s>
Type	O
1	O
drivers	O
also	O
do	O
n't	O
support	O
the	O
complete	O
Java	B-Language
command	O
set	O
and	O
are	O
limited	O
by	O
the	O
functionality	O
of	O
the	O
ODBC	B-Application
driver	O
.	O
</s>
<s>
Sun	O
(	O
now	O
Oracle	O
)	O
provided	O
a	O
JDBC-ODBC	B-Application
Bridge	I-Application
driver	O
:	O
sun.jdbc.odbc.JdbcOdbcDriver	O
.	O
</s>
<s>
This	O
driver	O
is	O
native	O
code	O
and	O
not	O
Java	B-Language
,	O
and	O
is	O
closed	O
source	O
.	O
</s>
<s>
Oracle	O
's	O
JDBC-ODBC	B-Application
Bridge	I-Application
was	O
removed	O
in	O
Java	B-Language
8	O
(	O
other	O
vendors	O
 '	O
are	O
available	O
)	O
.	O
</s>
<s>
If	O
a	O
driver	O
has	O
been	O
written	O
so	O
that	O
loading	O
it	O
causes	O
an	O
instance	O
to	O
be	O
created	O
and	O
also	O
calls	O
DriverManager.registerDriver	O
with	O
that	O
instance	O
as	O
the	O
parameter	O
,	O
then	O
it	O
is	O
in	O
the	O
DriverManager	O
's	O
list	O
of	O
drivers	O
and	O
available	O
for	O
creating	O
a	O
connection	B-General_Concept
.	O
</s>
<s>
It	O
may	O
sometimes	O
be	O
the	O
case	O
that	O
more	O
than	O
one	O
JDBC	B-Application
driver	I-Application
is	O
capable	O
of	O
connecting	O
to	O
a	O
given	O
URL	O
.	O
</s>
<s>
For	O
example	O
,	O
when	O
connecting	O
to	O
a	O
given	O
remote	O
database	O
,	O
it	O
might	O
be	O
possible	O
to	O
use	O
a	O
JDBC-ODBC	B-Application
bridge	I-Application
driver	O
,	O
a	O
JDBC-to-generic-network-protocol	O
driver	O
,	O
or	O
a	O
driver	O
supplied	O
by	O
the	O
database	O
vendor	O
.	O
</s>
<s>
(	O
The	O
drivers	O
listed	O
in	O
jdbc.drivers	O
are	O
always	O
registered	O
first	O
.	O
)	O
</s>
<s>
It	O
will	O
skip	O
any	O
drivers	O
that	O
are	O
untrusted	O
code	O
unless	O
they	O
have	O
been	O
loaded	O
from	O
the	O
same	O
source	O
as	O
the	O
code	O
that	O
is	O
trying	O
to	O
open	O
the	O
connection	B-General_Concept
.	O
</s>
<s>
The	O
first	O
driver	O
that	O
recognizes	O
the	O
URL	O
makes	O
the	O
connection	B-General_Concept
.	O
</s>
<s>
Almost	O
any	O
database	O
for	O
which	O
an	O
ODBC	B-Application
driver	O
is	O
installed	O
can	O
be	O
accessed	O
,	O
and	O
data	O
can	O
be	O
retrieved	O
.	O
</s>
<s>
Performance	O
overhead	O
since	O
the	O
calls	O
have	O
to	O
go	O
through	O
the	O
JDBC( java database connectivity )	O
bridge	O
to	O
the	O
ODBC(open database connectivity )	O
driver	O
,	O
then	O
to	O
the	O
native	O
database	O
connectivity	O
interface	O
(	O
thus	O
may	O
be	O
slower	O
than	O
other	O
types	O
of	O
drivers	O
)	O
.	O
</s>
<s>
The	O
ODBC	B-Application
driver	O
needs	O
to	O
be	O
installed	O
on	O
the	O
client	B-Protocol
machine	I-Protocol
.	O
</s>
<s>
Not	O
suitable	O
for	O
applets	O
,	O
because	O
the	O
ODBC	B-Application
driver	O
needs	O
to	O
be	O
installed	O
on	O
the	O
client	B-Protocol
.	O
</s>
<s>
Specific	O
ODBC	B-Application
drivers	O
are	O
not	O
always	O
available	O
on	O
all	O
platforms	O
;	O
hence	O
,	O
portability	O
of	O
this	O
driver	O
is	O
limited	O
.	O
</s>
<s>
No	O
support	O
from	O
JDK	O
1.8	O
(	O
Java	B-Language
8	O
)	O
.	O
</s>
<s>
The	O
JDBC	B-Language
type	O
2	O
driver	O
,	O
also	O
known	O
as	O
the	O
Native-API	O
driver	O
,	O
is	O
a	O
database	B-Application
driver	I-Application
implementation	O
that	O
uses	O
the	O
client-side	O
libraries	O
of	O
the	O
database	O
.	O
</s>
<s>
The	O
driver	O
converts	O
JDBC	B-Language
method	O
calls	O
into	O
native	O
calls	O
of	O
the	O
database	O
API	B-Application
.	O
</s>
<s>
As	O
there	O
is	O
no	O
implementation	O
of	O
JDBC-ODBC	B-Application
bridge	I-Application
,	O
it	O
may	O
be	O
considerably	O
faster	O
than	O
a	O
Type	O
1	O
driver	O
.	O
</s>
<s>
The	O
vendor	O
client	B-Protocol
library	O
needs	O
to	O
be	O
installed	O
on	O
the	O
client	B-Protocol
machine	I-Protocol
.	O
</s>
<s>
Not	O
all	O
databases	O
have	O
a	O
client-side	O
library	O
.	O
</s>
<s>
This	O
driver	O
is	O
platform	B-Operating_System
dependent	I-Operating_System
.	O
</s>
<s>
This	O
driver	O
supports	O
all	O
Java	B-Language
applications	O
except	O
applets	O
.	O
</s>
<s>
The	O
JDBC	B-Language
type	O
3	O
driver	O
,	O
also	O
known	O
as	O
the	O
Pure	O
Java	B-Language
driver	O
for	O
database	O
middleware	B-General_Concept
,	O
is	O
a	O
database	B-Application
driver	I-Application
implementation	O
which	O
makes	O
use	O
of	O
a	O
middle	B-Operating_System
tier	I-Operating_System
between	O
the	O
calling	O
program	O
and	O
the	O
database	O
.	O
</s>
<s>
The	O
middle-tier	O
(	O
application	B-Application
server	I-Application
)	O
converts	O
JDBC	B-Language
calls	O
directly	O
or	O
indirectly	O
into	O
a	O
vendor-specific	O
database	O
protocol	O
.	O
</s>
<s>
This	O
differs	O
from	O
the	O
type	O
4	O
driver	O
in	O
that	O
the	O
protocol	O
conversion	O
logic	O
resides	O
not	O
at	O
the	O
client	B-Protocol
,	O
but	O
in	O
the	O
middle-tier	O
.	O
</s>
<s>
Like	O
type	O
4	O
drivers	O
,	O
the	O
type	O
3	O
driver	O
is	O
written	O
entirely	O
in	O
Java	B-Language
.	O
</s>
<s>
The	O
same	O
client-side	O
JDBC	B-Application
driver	I-Application
may	O
be	O
used	O
for	O
multiple	O
databases	O
.	O
</s>
<s>
It	O
depends	O
on	O
the	O
number	O
of	O
databases	O
the	O
middleware	B-General_Concept
has	O
been	O
configured	O
to	O
support	O
.	O
</s>
<s>
The	O
type	O
3	O
driver	O
is	O
platform-independent	B-Operating_System
as	O
the	O
platform-related	O
differences	O
are	O
taken	O
care	O
of	O
by	O
the	O
middleware	B-General_Concept
.	O
</s>
<s>
Also	O
,	O
making	O
use	O
of	O
the	O
middleware	B-General_Concept
provides	O
additional	O
advantages	O
of	O
security	O
and	O
firewall	O
access	O
.	O
</s>
<s>
Sends	O
JDBC	B-Language
API	B-Application
calls	O
to	O
a	O
middle-tier	O
net	O
server	O
that	O
translates	O
the	O
calls	O
into	O
the	O
DBMS-specific	O
network	O
protocol	O
.	O
</s>
<s>
Follows	O
a	O
three-tier	B-Operating_System
communication	O
approach	O
.	O
</s>
<s>
The	O
JDBC	B-Language
Client	B-Protocol
driver	O
written	O
in	O
java	B-Language
,	O
communicates	O
with	O
a	O
middleware-net-server	O
using	O
a	O
database	O
independent	O
protocol	O
,	O
and	O
then	O
this	O
net	O
server	O
translates	O
this	O
request	O
into	O
database	O
commands	O
for	O
that	O
database	O
.	O
</s>
<s>
Thus	O
the	O
client	B-Protocol
driver	O
to	O
middleware	B-General_Concept
communication	O
is	O
database	O
independent	O
.	O
</s>
<s>
Since	O
the	O
communication	O
between	O
client	B-Protocol
and	O
the	O
middleware	B-General_Concept
server	O
is	O
database	O
independent	O
,	O
there	O
is	O
no	O
need	O
for	O
the	O
database	O
vendor	O
library	O
on	O
the	O
client	B-Protocol
.	O
</s>
<s>
The	O
client	B-Protocol
need	O
not	O
be	O
changed	O
for	O
a	O
new	O
database	O
.	O
</s>
<s>
The	O
middleware	B-General_Concept
server	O
(	O
which	O
can	O
be	O
a	O
full-fledged	O
J2EE	O
Application	B-Application
server	I-Application
)	O
can	O
provide	O
typical	O
middleware	B-General_Concept
services	O
like	O
caching	O
(	O
of	O
connections	O
,	O
query	O
results	O
,	O
etc	O
.	O
</s>
<s>
A	O
single	O
driver	O
can	O
handle	O
any	O
database	O
,	O
provided	O
the	O
middleware	B-General_Concept
supports	O
it	O
.	O
</s>
<s>
Requires	O
database-specific	O
coding	O
to	O
be	O
done	O
in	O
the	O
middle	B-Operating_System
tier	I-Operating_System
.	O
</s>
<s>
The	O
middleware	B-General_Concept
layer	O
added	O
may	O
result	O
in	O
additional	O
latency	O
,	O
but	O
is	O
typically	O
overcome	O
by	O
using	O
better	O
middleware	B-General_Concept
services	O
.	O
</s>
<s>
The	O
JDBC	B-Application
type	I-Application
4	I-Application
driver	I-Application
,	O
also	O
known	O
as	O
the	O
Direct	O
to	O
Database	O
Pure	O
Java	B-Language
Driver	O
,	O
is	O
a	O
database	B-Application
driver	I-Application
implementation	O
that	O
converts	O
JDBC	B-Language
calls	O
directly	O
into	O
a	O
vendor-specific	O
database	O
protocol	O
.	O
</s>
<s>
Written	O
completely	O
in	O
Java	B-Language
,	O
type	O
4	O
drivers	O
are	O
thus	O
platform	B-Operating_System
independent	I-Operating_System
.	O
</s>
<s>
They	O
install	O
inside	O
the	O
Java	B-Language
virtual	I-Language
machine	I-Language
of	O
the	O
client	B-Protocol
.	O
</s>
<s>
This	O
provides	O
better	O
performance	O
than	O
the	O
type	O
1	O
and	O
type	O
2	O
drivers	O
as	O
it	O
does	O
not	O
have	O
the	O
overhead	O
of	O
conversion	O
of	O
calls	O
into	O
ODBC	B-Application
or	O
database	O
API	B-Application
calls	O
.	O
</s>
<s>
As	O
the	O
database	O
protocol	O
is	O
vendor	O
specific	O
,	O
the	O
JDBC	B-Language
client	B-Protocol
requires	O
separate	O
drivers	O
,	O
usually	O
vendor	O
supplied	O
,	O
to	O
connect	O
to	O
different	O
types	O
of	O
databases	O
.	O
</s>
<s>
Completely	O
implemented	O
in	O
Java	B-Language
to	O
achieve	O
platform	B-Operating_System
independence	I-Operating_System
.	O
</s>
<s>
These	O
drivers	O
do	O
n't	O
translate	O
the	O
requests	O
into	O
an	O
intermediary	O
format	O
(	O
such	O
as	O
ODBC	B-Application
)	O
.	O
</s>
<s>
The	O
client	B-Protocol
application	I-Protocol
connects	O
directly	O
to	O
the	O
database	O
server	O
.	O
</s>
<s>
No	O
translation	O
or	O
middleware	B-General_Concept
layers	O
are	O
used	O
,	O
improving	O
performance	O
.	O
</s>
<s>
The	O
JVM	B-Language
can	O
manage	O
all	O
aspects	O
of	O
the	O
application-to-database	O
connection	O
;	O
this	O
can	O
facilitate	O
debugging	O
.	O
</s>
