<s>
In	O
software	B-General_Concept
engineering	I-General_Concept
,	O
a	O
connection	B-General_Concept
pool	I-General_Concept
is	O
a	O
cache	B-General_Concept
of	O
database	B-General_Concept
connections	I-General_Concept
maintained	O
so	O
that	O
the	O
connections	O
can	O
be	O
reused	O
when	O
future	O
requests	O
to	O
the	O
database	O
are	O
required	O
.	O
</s>
<s>
Connection	B-General_Concept
pools	I-General_Concept
are	O
used	O
to	O
enhance	O
the	O
performance	O
of	O
executing	O
commands	O
on	O
a	O
database	O
.	O
</s>
<s>
Opening	O
and	O
maintaining	O
a	O
database	B-General_Concept
connection	I-General_Concept
for	O
each	O
user	O
,	O
especially	O
requests	O
made	O
to	O
a	O
dynamic	O
database-driven	O
website	O
application	O
,	O
is	O
costly	O
and	O
wastes	O
resources	O
.	O
</s>
<s>
In	O
connection	B-General_Concept
pooling	I-General_Concept
,	O
after	O
a	O
connection	O
is	O
created	O
,	O
it	O
is	O
placed	O
in	O
the	O
pool	O
and	O
it	O
is	O
used	O
again	O
so	O
that	O
a	O
new	O
connection	O
does	O
not	O
have	O
to	O
be	O
established	O
.	O
</s>
<s>
Connection	B-General_Concept
pooling	I-General_Concept
also	O
cuts	O
down	O
on	O
the	O
amount	O
of	O
time	O
a	O
user	O
must	O
wait	O
to	O
establish	O
a	O
connection	O
to	O
the	O
database	O
.	O
</s>
<s>
Web-based	O
and	O
enterprise	B-Application
applications	I-Application
use	O
an	O
application	B-Application
server	I-Application
to	O
handle	O
connection	B-General_Concept
pooling	I-General_Concept
.	O
</s>
<s>
Dynamic	O
web	O
pages	O
without	O
connection	B-General_Concept
pooling	I-General_Concept
open	O
connections	O
to	O
database	O
services	O
as	O
required	O
and	O
close	O
them	O
when	O
the	O
page	O
is	O
done	O
servicing	O
a	O
particular	O
request	O
.	O
</s>
<s>
Pages	O
that	O
use	O
connection	B-General_Concept
pooling	I-General_Concept
,	O
on	O
the	O
other	O
hand	O
,	O
maintain	O
open	O
connections	O
in	O
a	O
pool	O
.	O
</s>
<s>
Local	O
applications	O
that	O
need	O
frequent	O
access	O
to	O
databases	O
can	O
also	O
benefit	O
from	O
connection	B-General_Concept
pooling	I-General_Concept
.	O
</s>
<s>
Open	O
connections	O
can	O
be	O
maintained	O
in	O
local	O
applications	O
that	O
do	O
not	O
need	O
to	O
service	O
separate	O
remote	O
requests	O
like	O
application	B-Application
servers	I-Application
,	O
but	O
implementations	O
of	O
connection	B-General_Concept
pooling	I-General_Concept
can	O
become	O
complicated	O
.	O
</s>
<s>
A	O
number	O
of	O
available	O
libraries	B-Library
implement	O
connection	B-General_Concept
pooling	I-General_Concept
and	O
related	O
SQL	O
query	O
pooling	O
,	O
simplifying	O
the	O
implementation	O
of	O
connection	B-General_Concept
pools	I-General_Concept
in	O
database-intensive	O
applications	O
.	O
</s>
<s>
Administrators	O
can	O
configure	O
connection	B-General_Concept
pools	I-General_Concept
with	O
restrictions	O
on	O
the	O
numbers	O
of	O
minimum	O
connections	O
,	O
maximum	O
connections	O
and	O
idle	O
connections	O
to	O
optimize	O
the	O
performance	O
of	O
pooling	O
in	O
specific	O
problem	O
contexts	O
and	O
in	O
specific	O
environments	O
.	O
</s>
