<s>
Database-centric	B-Operating_System
Architecture	I-Operating_System
or	O
data-centric	B-Operating_System
architecture	I-Operating_System
has	O
several	O
distinct	O
meanings	O
,	O
generally	O
relating	O
to	O
software	B-Architecture
architectures	I-Architecture
in	O
which	O
databases	B-Application
play	O
a	O
crucial	O
role	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
characterization	O
of	O
an	O
architecture	O
as	O
"	O
database-centric	B-Operating_System
"	O
may	O
mean	O
any	O
combination	O
of	O
the	O
following	O
:	O
</s>
<s>
using	O
a	O
standard	O
,	O
general-purpose	O
relational	B-Application
database	I-Application
management	I-Application
system	I-Application
,	O
as	O
opposed	O
to	O
customized	O
in-memory	O
or	O
file-based	O
data	B-General_Concept
structures	I-General_Concept
and	O
access	B-Application
methods	I-Application
.	O
</s>
<s>
With	O
the	O
evolution	O
of	O
sophisticated	O
DBMS	B-Application
software	O
,	O
much	O
of	O
which	O
is	O
either	O
free	O
or	O
included	O
with	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
application	O
developers	O
have	O
become	O
increasingly	O
reliant	O
on	O
standard	O
database	O
tools	O
,	O
especially	O
for	O
the	O
sake	O
of	O
rapid	O
application	O
development	O
.	O
</s>
<s>
using	O
dynamic	O
,	O
table-driven	O
logic	O
,	O
as	O
opposed	O
to	O
logic	O
embodied	O
in	O
previously	O
compiled	B-Language
programs	O
.	O
</s>
<s>
The	O
use	O
of	O
table-driven	O
logic	O
,	O
i.e.	O
</s>
<s>
This	O
capability	O
is	O
a	O
central	O
feature	O
of	O
dynamic	B-Language
programming	I-Language
languages	I-Language
.	O
</s>
<s>
See	O
also	O
control	B-Application
tables	I-Application
for	O
tables	O
that	O
are	O
normally	O
coded	O
and	O
embedded	O
within	O
programs	O
as	O
data	B-General_Concept
structures	I-General_Concept
(	O
i.e.	O
</s>
<s>
not	O
compiled	B-Language
statements	O
)	O
but	O
could	O
equally	O
be	O
read	O
in	O
from	O
a	O
flat	B-Application
file	I-Application
,	O
database	O
or	O
even	O
retrieved	O
from	O
a	O
spreadsheet	B-Application
.	O
</s>
<s>
using	O
stored	B-General_Concept
procedures	I-General_Concept
that	O
run	O
on	O
database	B-Application
servers	I-Application
,	O
as	O
opposed	O
to	O
greater	O
reliance	O
on	O
logic	O
running	O
in	O
middle-tier	O
application	B-Application
servers	I-Application
in	O
a	O
multi-tier	B-Operating_System
architecture	I-Operating_System
.	O
</s>
<s>
The	O
extent	O
to	O
which	O
business	B-Architecture
logic	I-Architecture
should	O
be	O
placed	O
at	O
the	O
back-end	O
versus	O
another	O
tier	B-Operating_System
is	O
a	O
subject	O
of	O
ongoing	O
debate	O
.	O
</s>
<s>
For	O
example	O
,	O
Toon	O
Koppelaars	O
presents	O
a	O
detailed	O
analysis	O
of	O
alternative	O
Oracle-based	B-General_Concept
architectures	O
that	O
vary	O
in	O
the	O
placement	O
of	O
business	B-Architecture
logic	I-Architecture
,	O
concluding	O
that	O
a	O
database-centric	B-Operating_System
approach	O
has	O
practical	O
advantages	O
from	O
the	O
standpoint	O
of	O
ease	O
of	O
development	O
and	O
maintainability	O
.	O
</s>
<s>
using	O
a	O
shared	O
database	O
as	O
the	O
basis	O
for	O
communicating	O
between	O
parallel	B-Operating_System
processes	I-Operating_System
in	O
distributed	B-Architecture
computing	I-Architecture
applications	O
,	O
as	O
opposed	O
to	O
direct	O
inter-process	B-Operating_System
communication	I-Operating_System
via	O
message	B-Architecture
passing	I-Architecture
functions	O
and	O
message-oriented	B-Application
middleware	I-Application
.	O
</s>
<s>
A	O
potential	O
benefit	O
of	O
database-centric	B-Operating_System
architecture	I-Operating_System
in	O
distributed	B-Architecture
applications	I-Architecture
is	O
that	O
it	O
simplifies	O
the	O
design	O
by	O
utilizing	O
DBMS-provided	O
transaction	B-General_Concept
processing	I-General_Concept
and	O
indexing	B-Data_Structure
to	O
achieve	O
a	O
high	O
degree	O
of	O
reliability	O
,	O
performance	O
,	O
and	O
capacity	O
.	O
</s>
<s>
For	O
example	O
,	O
Base	O
One	O
describes	O
a	O
database-centric	B-Operating_System
distributed	B-Architecture
computing	I-Architecture
architecture	I-Architecture
for	O
grid	B-Architecture
and	O
cluster	B-Architecture
computing	I-Architecture
,	O
and	O
explains	O
how	O
this	O
design	O
provides	O
enhanced	O
security	O
,	O
fault-tolerance	O
,	O
and	O
scalability	B-Architecture
.	O
</s>
<s>
Even	O
an	O
extreme	O
database-centric	B-Operating_System
architecture	I-Operating_System
called	O
RDBMS-only	O
architecture	O
has	O
been	O
proposed	O
,	O
in	O
which	O
the	O
three	O
classic	O
layers	O
of	O
an	O
application	O
are	O
kept	O
within	O
the	O
RDBMS	O
.	O
</s>
<s>
This	O
architecture	O
heavily	O
uses	O
the	O
DBPL	O
(	O
Database	B-Application
Programming	I-Application
Language	O
)	O
of	O
the	O
RDBMS	O
.	O
</s>
<s>
An	O
example	O
of	O
software	O
with	O
this	O
architecture	O
is	O
Oracle	B-Application
Application	I-Application
Express	I-Application
(	O
APEX	O
)	O
.	O
</s>
