<s>
The	O
following	O
tables	O
compare	O
general	O
and	O
technical	O
information	O
for	O
a	O
number	O
of	O
relational	B-Application
database	I-Application
management	I-Application
systems	I-Application
.	O
</s>
<s>
Maintainer	O
First	O
public	O
release	O
date	O
Latest	O
stable	O
version	O
Latest	O
release	O
date	O
License	O
Public	O
issues	O
list	O
4D	B-Language
(	O
4th	B-Language
Dimension	I-Language
)	O
4D	B-Language
S.A.S.	O
</s>
<s>
1984	O
v16.0	O
2017-01-10	O
ADABAS	B-Application
Software	O
AG	O
1970	O
8.12013-06	O
Adaptive	B-Application
Server	I-Application
Enterprise	I-Application
SAP	B-Application
AG	I-Application
1987	O
16.0	O
SP03	O
PL072019-06-10	O
Advantage	B-Application
Database	I-Application
Server	I-Application
(	O
ADS	O
)	O
SAP	B-Application
AG	I-Application
1992	O
12.0	O
2015	O
Altibase	B-Operating_System
Altibase	B-Operating_System
Corp	O
.	O
2000	O
7.1.0.1.2	O
2018-03-02	O
Proprietary	B-Application
Apache	B-Language
Derby	I-Language
Apache	O
2004	O
10.15.1.3	O
2019-03-11	O
Derby	O
-	O
ASF	O
JIRA	O
ClustrixDB	O
MariaDB	B-Application
Corporation	I-Application
2010	O
v7.0	O
2015-08-19	O
CockroachDB	B-Operating_System
Cockroach	B-Operating_System
Labs	I-Operating_System
2015	O
v20.2.8	O
2021-04-23	O
cockroachdb	B-Operating_System
Issue	O
tracker	O
CUBRID	B-Application
CUBRID	B-Application
2008-11	O
11.2.3	O
2023-01-31	O
CUBRID	B-Application
/	O
Jira	O
Issue	O
tracker	O
for	O
CUBRID	B-Application
Datacom	B-Application
CA	O
,	O
Inc	O
.	O
</s>
<s>
Early	O
70s	O
14	O
2012	O
IBM	B-Application
Db2	I-Application
IBM	O
1983	O
;	O
Empress	B-Application
Embedded	I-Application
Database	I-Application
Empress	O
Software	O
Inc	O
1979	O
10.20	O
2010-03	O
Exasol	O
EXASOL	O
AG	O
2004	O
7.1.1	O
2021-09-15	O
;	O
FileMaker	B-Application
FileMaker	B-Application
,	O
Inc.	O
,	O
an	O
Apple	O
subsidiary	O
1985-04	O
19	O
2020-05-20	O
Firebird	B-Application
Firebird	B-Application
project	O
2000-07-25	O
;	O
Firebird	B-Application
RDBMS	O
Issue	O
Tracker	O
GPUdb	B-Application
GIS	O
Federal	O
2014	O
3.2.5	O
2015-01-14	O
HSQLDB	B-Application
HSQL	B-Application
Development	O
Group	O
2001	O
2.6.1	O
2021-10-21	O
HyperSQL	B-Application
Database	O
Engine	O
(	O
HSQLDB	B-Application
)	O
/	O
Bugs	O
H2	B-Language
H2	B-Language
Software	O
2005	O
2.1.214	O
2022-06-13	O
h2database	O
issues	O
Informix	B-Application
Dynamic	I-Application
Server	I-Application
IBM	O
/	O
HCL	O
Technologies	O
1981	O
???	O
</s>
<s>
?	O
1980	O
14.10.xC9	O
2022-10-03	O
Ingres	B-Application
Actian	O
1974	O
11.2	O
2022-05-06	O
InterBase	B-Application
Embarcadero	B-Application
1984	O
XE7	O
v12.0.4.357	O
2015-08-12	O
Linter	B-Application
SQL	I-Application
RDBMS	I-Application
RELEX	O
Group	O
1990	O
6.0.17.53	O
2018-02-15	O
Linter	B-Application
Techsupport	O
LucidDB	B-Application
The	O
Eigenbase	O
Project	O
2007-01	O
0.9.4	O
2012-01-05	O
MariaDB	B-Application
MariaDB	B-Application
Community	I-Application
2010-02-01	O
;	O
MariaDB	B-Application
-	O
JIRA	O
MaxDB	B-Application
SAP	B-Application
AG	I-Application
2003-05	O
7.9.0.8	O
2014	O
MaxDB	B-Application
-	O
Problem	O
TrackingSingleStore	O
(	O
formerly	O
MemSQL	B-Application
)	O
SingleStore	B-Application
2012-06	O
7.1.11	O
2020-10-12	O
Microsoft	B-Application
Access	I-Application
(	O
JET	O
)	O
Microsoft	O
1992	O
16	O
(	O
2016	O
)	O
2015-09-22	O
Microsoft	B-Application
Visual	I-Application
Foxpro	I-Application
Microsoft	O
1984	O
9	O
(	O
2005	O
)	O
2007-10-11	O
Microsoft	B-Application
SQL	I-Application
Server	I-Application
Microsoft	O
1989	O
;	O
Microsoft	B-Operating_System
SQL	I-Operating_System
Server	I-Operating_System
Compact	I-Operating_System
(	O
Embedded	O
Database	O
)	O
Microsoft	O
2000	O
2011	O
(	O
v4.0	O
)	O
Mimer	B-Application
SQL	I-Application
Mimer	O
Information	O
Technology	O
1978	O
11.0.7D	O
2023-02-06	O
MonetDB	B-Application
The	O
MonetDB	B-Application
Team	O
/	O
CWI	O
2004	O
Sep2022-SP1	O
2022-12-09	O
MonetDB	B-Application
Issues	O
mSQL	B-Application
Hughes	O
Technologies	O
1994	O
4.1	O
2017-06-30	O
MySQL	B-Application
Oracle	B-Application
Corporation	I-Application
1995-11	O
;	O
MySQL	B-Application
Bugs	O
NexusDB	B-Language
NexusDB	B-Language
Pty	O
Ltd	O
2003	O
4.00.14	O
2015-06-25	O
HPE	B-Application
NonStop	I-Application
SQL	I-Application
Hewlett-Packard	O
Enterprise	O
1987	O
SQL/MX	O
3.4	O
NuoDB	B-Application
NuoDB	B-Application
2013	O
4.1	O
2020-08	O
Omnis	B-Application
Studio	I-Application
TigerLogic	O
Inc	O
1982-07	O
6.1.3	O
Release	O
1no	O
2015-12	O
OpenEdge	B-Application
Progress	O
Software	O
Corporation	O
1984	O
11.6.3	O
2016-08-19	O
OpenLink	B-Application
Virtuoso	I-Application
OpenLink	O
Software	O
1998	O
7.2.5.1	O
2018-08-15	O
Issues	O
·	O
openlink/virtuoso	O
-opensource	O
·	O
GitHub	B-Application
Oracle	B-General_Concept
DB	I-General_Concept
Oracle	B-Application
Corporation	I-Application
1979-11	O
;	O
Oracle	B-Application
Rdb	I-Application
Oracle	B-Application
Corporation	I-Application
1984	O
Paradox	B-Application
Corel	O
Corporation	O
1985	O
11	O
2009-09-07	O
Percona	B-Application
Server	I-Application
for	I-Application
MySQL	I-Application
Percona	B-Language
2006	O
Actian	O
Zen	O
(	O
PSQL	O
)	O
Actian	O
1982	O
v15	O
2021	O
Polyhedra	B-Application
DBMS	I-Application
ENEA	B-Operating_System
AB	I-Operating_System
1993	O
9.0	O
2015-06-24	O
,	O
with	O
Polyhedra	B-Application
Lite	O
available	O
as	O
Freeware	B-License
.	O
</s>
<s>
PostgreSQL	B-Application
PostgreSQL	B-Application
Global	O
Development	O
Group	O
1989-06	O
;	O
Postgres	B-Application
License	I-Application
A	O
bug	O
tracker	O
for	O
PostgreSQL	B-Application
?	O
</s>
<s>
The	O
operating	B-General_Concept
systems	I-General_Concept
that	O
the	O
RDBMSes	O
can	O
run	O
on	O
.	O
</s>
<s>
Note	O
(	O
2	O
)	O
:	O
MariaDB	B-Application
and	O
MySQL	B-Application
provide	O
ACID	O
compliance	O
through	O
the	O
default	O
InnoDB	B-Language
storage	O
engine	O
.	O
</s>
<s>
Note	O
(	O
3	O
)	O
:	O
"	O
For	O
other	O
than	O
InnoDB	B-Language
storage	O
engines	O
,	O
MySQL	B-Application
Server	I-Application
parses	O
and	O
ignores	O
the	O
FOREIGN	O
KEY	O
and	O
REFERENCES	O
syntax	O
in	O
CREATE	O
TABLE	B-Application
statements	O
.	O
</s>
<s>
Note	O
(	O
5	O
)	O
:	O
MySQL	B-Application
provides	O
GUI	B-Application
interface	O
through	O
MySQL	B-Language
Workbench	I-Language
.	O
</s>
<s>
Note	O
(	O
6	O
)	O
:	O
OpenEdge	B-Application
SQL	B-Language
database	I-Language
engine	O
uses	O
Referential	B-General_Concept
Integrity	I-General_Concept
,	O
OpenEdge	B-Application
ABL	I-Application
Database	O
engine	O
does	O
not	O
and	O
is	O
handled	O
via	O
database	B-Language
triggers	I-Language
.	O
</s>
<s>
Max	O
DB	O
size	O
Max	O
table	B-Application
size	O
Max	O
row	O
size	O
Max	O
columns	O
per	O
row	O
Max	O
Blob/Clob	O
size	O
Max	O
CHAR	O
size	O
Max	O
NUMBER	O
size	O
Min	O
DATE	O
value	O
Max	O
DATE	O
value	O
Max	O
column	O
name	O
size	O
4th	B-Language
Dimension	I-Language
Limited	O
65,135	O
200	O
GB	O
(	O
2	O
GiB	O
Unicode	O
)	O
200	O
GB	O
(	O
2	O
GiB	O
Unicode	O
)	O
64	O
bits	O
Advantage	B-Application
Database	I-Application
Server	I-Application
Unlimited	O
16	O
EiB	O
65,530	O
B	O
65,135	O
/	O
(	O
10+	O
AvgFieldNameLength	O
)	O
4	O
GiB	O
64	O
bits	O
128	O
Apache	B-Language
Derby	I-Language
Unlimited	O
Unlimited	O
Unlimited	O
1,012	O
(	O
5,000	O
in	O
views	O
)	O
2,147,483,647	O
chars	O
254	O
(	O
VARCHAR	O
:	O
32,672	O
)	O
64	O
bits	O
0001-01-01	O
9999-12-31	O
128	O
ClustrixDB	O
Unlimited	O
Unlimited	O
64	O
MB	O
on	O
Appliance	O
,	O
4	O
MB	O
on	O
AWS	O
64	O
MB	O
64	O
MB	O
64	O
MB	O
0001-01-01	O
9999-12-31	O
254	O
CUBRID	B-Application
2	O
EB	O
2	O
EB	O
Unlimited	O
Unlimited	O
Unlimited	O
1	O
GB	O
64	O
bits	O
0001-01-01	O
9999-12-31	O
254	O
IBM	B-Application
Db2	I-Application
Unlimited	O
2	O
ZB	O
1,048,319	O
B	O
1,012	O
2	O
GB	O
32	O
KiB	O
64	O
bits	O
0001-01-01	O
9999-12-31	O
128	O
Empress	B-Application
Embedded	I-Application
Database	I-Application
Unlimited	O
263-1	O
bytes	O
2	O
GB	O
32,767	O
2	O
GB	O
2	O
GB	O
64	O
bits	O
0000-01-01	O
9999-12-31	O
32	O
EXASolution	O
Unlimited	O
Unlimited	O
Unlimited	O
10,000	O
N/A	O
2	O
MB	O
128	O
bits	O
0001-01-01	O
9999-12-31	O
256	O
FileMaker	B-Application
8	O
TB	O
8	O
TB	O
8	O
TB	O
256,000,000	O
4	O
GB	O
10,000,000	O
1	O
billion	O
characters	O
,	O
10^	O
-400	O
to	O
10^400	O
,	O
+	O
-	O
0001-01-01	O
4000-12-31	O
100	O
FirebirdUnlimited1	O
~	O
32	O
TB	O
65,536	O
B	O
Depends	O
on	O
data	O
types	O
used	O
32	O
GB	O
32,767	O
B	O
64	O
bits	O
100	O
32768	O
31	O
HSQLDB	B-Application
64	O
TB	O
Unlimited8	O
Unlimited8	O
Unlimited8	O
64	O
TB7	O
Unlimited8	O
Unlimited8	O
0001-01-01	O
9999-12-31	O
128	O
H2	B-Language
64	O
TB	O
Unlimited8	O
Unlimited8	O
Unlimited8	O
64	O
TB7	O
Unlimited8	O
64	O
bits	O
-99999999	O
99999999	O
Unlimited8	O
Max	O
DB	O
size	O
Max	O
table	B-Application
size	O
Max	O
row	O
size	O
Max	O
columns	O
per	O
row	O
Max	O
Blob/Clob	O
size	O
Max	O
CHAR	O
size	O
Max	O
NUMBER	O
size	O
Min	O
DATE	O
value	O
Max	O
DATE	O
value	O
Max	O
column	O
name	O
size	O
Informix	B-Application
Dynamic	I-Application
Server	I-Application
~	O
128	O
PB12	O
~	O
128	O
PB12	O
32,765	O
bytes	O
(	O
exclusive	O
of	O
large	O
objects	O
)	O
32,765	O
4	O
TB	O
32,765	O
10125	O
13	O
01/01/000110	O
12/31/9999	O
128	O
bytes	O
Ingres	B-Application
Unlimited	O
Unlimited	O
256	O
KB	O
1,024	O
2	O
GB	O
32	O
000	O
B	O
64	O
bits	O
0001	O
9999	O
256	O
InterBaseUnlimited1	O
~	O
32	O
TB	O
65,536	O
B	O
Depends	O
on	O
data	O
types	O
used	O
2	O
GB	O
32,767	O
B	O
64	O
bits	O
100	O
32768	O
31	O
Linter	B-Application
SQL	I-Application
RDBMS	I-Application
Unlimited	O
230	O
rows	O
64	O
KB	O
(	O
w/o	O
BLOBs	B-General_Concept
)	O
,	O
2GB	O
(	O
each	O
BLOB	B-General_Concept
value	O
)	O
250	O
2	O
GB	O
4000	O
B	O
64	O
bits	O
0001-01-01	O
9999-12-31	O
66	O
MariaDB	B-Application
Unlimited	O
MyISAM	B-Language
storage	O
limits	O
:	O
256	O
TB	O
;	O
Innodb	B-Language
storage	O
limits	O
:	O
64	O
TB	O
;	O
Aria	B-Application
storage	O
limits	O
:	O
?	O
</s>
<s>
Note	O
(	O
1	O
)	O
:	O
Firebird	B-Application
2.x	O
maximum	O
database	O
size	O
is	O
effectively	O
unlimited	O
with	O
the	O
largest	O
known	O
database	O
size	O
>980	O
GB	O
.	O
</s>
<s>
Firebird	B-Application
1.5.x	O
maximum	O
database	O
size	O
:	O
32	O
TB	O
.	O
</s>
<s>
Note	O
(	O
3	O
)	O
:	O
InnoDB	B-Language
is	O
limited	O
to	O
8,000	O
bytes	O
(	O
excluding	O
VARBINARY	O
,	O
VARCHAR	O
,	O
BLOB	B-General_Concept
,	O
or	O
TEXT	O
columns	O
)	O
.	O
</s>
<s>
Note	O
(	O
4	O
)	O
:	O
InnoDB	B-Language
is	O
limited	O
to	O
1,017	O
columns	O
.	O
</s>
<s>
Note	O
(	O
6	O
)	O
:	O
Using	O
VARCHAR	O
(	O
MAX	O
)	O
in	O
SQL	B-Language
2005	O
and	O
later	O
.	O
</s>
<s>
Note	O
(	O
7	O
)	O
:	O
When	O
using	O
a	O
page	O
size	O
of	O
32	O
KB	O
,	O
and	O
when	O
BLOB/CLOB	O
data	O
is	O
stored	O
in	O
the	O
database	O
file	O
.	O
</s>
<s>
This	O
limit	O
applies	O
to	O
number	O
of	O
characters	O
in	O
names	O
,	O
rows	O
per	O
table	B-Application
,	O
columns	O
per	O
table	B-Application
,	O
and	O
characters	O
per	O
CHAR/VARCHAR	O
.	O
</s>
<s>
Note	O
(	O
9	O
)	O
:	O
Despite	O
the	O
lack	O
of	O
a	O
date	O
datatype	O
,	O
SQLite	B-Language
does	O
include	O
date	O
and	O
time	O
functions	O
,	O
which	O
work	O
for	O
timestamps	O
between	O
24	O
November	O
4714	O
B.C.	O
</s>
<s>
Note	O
(	O
10	O
)	O
:	O
Informix	B-Application
DATETIME	O
type	O
has	O
adjustable	O
range	O
from	O
YEAR	O
only	O
through	O
1/10000th	O
second	O
.	O
</s>
<s>
Note	O
(	O
12	O
)	O
:	O
The	O
128PB	O
limit	O
refers	O
to	O
the	O
storage	O
limit	O
of	O
a	O
single	O
Informix	B-Application
server	O
instance	O
.	O
</s>
<s>
Informix	B-Application
v12.10	O
and	O
later	O
versions	O
support	O
using	O
sharding	O
techniques	O
to	O
distribute	O
a	O
table	B-Application
across	O
multiple	O
server	O
instances	O
.	O
</s>
<s>
A	O
distributed	O
Informix	B-Application
database	O
has	O
no	O
upper	O
limit	O
on	O
table	B-Application
or	O
database	O
size	O
.	O
</s>
<s>
Note	O
(	O
13	O
)	O
:	O
Informix	B-Application
DECIMAL	O
type	O
supports	O
up	O
to	O
32	O
decimal	O
digits	O
of	O
precision	O
with	O
a	O
range	O
of	O
10^	O
-130	O
to	O
10^125	O
.	O
</s>
<s>
Note	O
(	O
2	O
)	O
:	O
Materialized	B-Application
views	I-Application
are	O
not	O
supported	O
in	O
Informix	B-Application
;	O
the	O
term	O
is	O
used	O
in	O
IBM	O
's	O
documentation	O
to	O
refer	O
to	O
a	O
temporary	O
table	B-Application
created	O
to	O
run	O
the	O
view	B-Language
's	O
query	O
when	O
it	O
is	O
too	O
complex	O
,	O
but	O
one	O
cannot	O
for	O
example	O
define	O
the	O
way	O
it	O
is	O
refreshed	O
or	O
build	O
an	O
index	O
on	O
it	O
.	O
</s>
<s>
The	O
term	O
is	O
defined	O
in	O
the	O
Informix	B-Application
Performance	O
Guide	O
.	O
</s>
<s>
Note	O
(	O
4	O
)	O
:	O
Materialized	B-Application
views	I-Application
can	O
be	O
emulated	O
using	O
stored	B-General_Concept
procedures	I-General_Concept
and	O
triggers	O
.	O
</s>
<s>
Information	O
about	O
what	O
indexes	B-Data_Structure
(	O
other	O
than	O
basic	O
B-/B	O
+	O
tree	O
indexes	B-Data_Structure
)	O
are	O
supported	O
natively	O
.	O
</s>
<s>
Note	O
(	O
2	O
)	O
:	O
Can	O
be	O
implemented	O
for	O
most	O
data	O
types	O
using	O
expression-based	O
indexes	B-Data_Structure
.	O
</s>
<s>
Note	O
(	O
3	O
)	O
:	O
Can	O
be	O
emulated	O
by	O
indexing	O
a	O
computed	O
column	O
(	O
does	O
n't	O
easily	O
update	O
)	O
or	O
by	O
using	O
an	O
"	O
Indexed	O
View	B-Language
"	O
(	O
proper	O
name	O
not	O
just	O
any	O
view	B-Language
works	O
)	O
.	O
</s>
<s>
Note	O
(	O
4	O
)	O
:	O
Used	O
for	O
InMemory	O
ColumnStore	O
index	O
,	O
temporary	O
hash	B-Error_Name
index	O
for	O
hash	B-Error_Name
join	O
,	O
Non/Cluster	O
&	O
fill	O
factor	O
.	O
</s>
<s>
Note	O
(	O
5	O
)	O
:	O
InnoDB	B-Language
automatically	O
generates	O
adaptive	O
hash	B-Error_Name
index	O
entries	O
as	O
needed	O
.	O
</s>
<s>
Note	O
(	O
6	O
)	O
:	O
Can	O
be	O
implemented	O
using	O
Function-based	O
Indexes	B-Data_Structure
in	O
Oracle	B-General_Concept
8i	O
and	O
higher	O
,	O
but	O
the	O
function	O
needs	O
to	O
be	O
used	O
in	O
the	O
sql	B-Language
for	O
the	O
index	O
to	O
be	O
used	O
.	O
</s>
<s>
Note	O
(	O
7	O
)	O
:	O
A	O
PostgreSQL	B-Application
functional	O
index	O
can	O
be	O
used	O
to	O
reverse	B-Data_Structure
the	O
order	O
of	O
a	O
field	O
.	O
</s>
<s>
Note	O
(	O
10	O
)	O
:	O
B+	O
tree	O
and	O
full-text	B-Application
only	O
for	O
now	O
.	O
</s>
<s>
Note	O
(	O
11	O
)	O
:	O
R-Tree	B-Library
indexing	O
available	O
in	O
base	O
edition	O
with	O
Locator	O
but	O
some	O
functionality	O
requires	O
Personal	O
Edition	O
or	O
Enterprise	O
Edition	O
with	O
Spatial	O
option	O
.	O
</s>
<s>
Data	B-Application
Domain	I-Application
Cursor	B-Language
Trigger	B-Language
Function	I-Language
1	O
Procedure	O
1	O
External	O
routine	O
1	O
4th	B-Language
Dimension	I-Language
ADABAS	B-Application
?	O
</s>
<s>
Note	O
(	O
1	O
)	O
:	O
Both	O
function	O
and	O
procedure	O
refer	O
to	O
internal	O
routines	O
written	O
in	O
SQL	B-Language
and/or	O
procedural	O
language	O
like	O
PL/SQL	B-Language
.	O
</s>
<s>
"	O
Stored	B-General_Concept
procedure	I-General_Concept
"	O
is	O
a	O
commonly	O
used	O
term	O
for	O
these	O
routine	O
types	O
.	O
</s>
<s>
Note	O
(	O
2	O
)	O
:	O
In	O
Derby	O
,	O
H2	B-Language
,	O
LucidDB	B-Application
,	O
and	O
CUBRID	B-Application
,	O
users	O
code	O
functions	O
and	O
procedures	O
in	O
Java	O
.	O
</s>
<s>
Note	O
(	O
5	O
)	O
:	O
Informix	B-Application
supports	O
external	O
functions	O
written	O
in	O
Java	O
,	O
C	O
,	O
&	O
C++	O
.	O
</s>
<s>
Information	O
about	O
what	O
partitioning	B-General_Concept
methods	O
are	O
supported	O
natively	O
.	O
</s>
<s>
Note	O
(	O
1	O
)	O
:	O
Raima	B-Application
Database	I-Application
Manager	I-Application
14.0	O
requires	O
the	O
application	O
programs	O
to	O
select	O
the	O
correct	O
partition	B-General_Concept
(	O
using	O
range	O
,	O
hash	B-Error_Name
or	O
composite	O
techniques	O
)	O
when	O
adding	O
data	O
,	O
but	O
the	O
database	O
union	B-Language
functionality	O
allows	O
all	O
partitions	B-General_Concept
to	O
be	O
read	O
as	O
a	O
single	O
database	O
.	O
</s>
<s>
Native	O
network	O
encryption1	O
Brute-force	O
protection	O
Enterprise	O
directory	O
compatibility	O
Password	O
complexity	O
rules2	O
Patch	O
access3	O
Run	O
unprivileged4	O
Audit	O
Resource	O
limit	O
Separation	O
of	O
duties	O
(	O
RBAC	O
)	O
5	O
Security	O
Certification	O
Attribute-Based	O
Access	O
Control	O
(	O
ABAC	O
)	O
4D	B-Language
(	O
with	O
SSL	O
)	O
Adaptive	B-Application
Server	I-Application
Enterprise	I-Application
(	O
optional	O
;	O
to	O
pay	O
)	O
(	O
optional	O
?	O
)	O
</s>
<s>
(	O
need	O
to	O
register	O
;	O
depend	O
on	O
which	O
product	O
)	O
(	O
EAL4+	O
1	O
)	O
Advantage	B-Application
Database	I-Application
Server	I-Application
CUBRID	B-Application
(	O
with	O
SSL	O
)	O
IBM	B-Application
Db2	I-Application
(	O
LDAP	O
,	O
Kerberos	O
...	O
)	O
(	O
EAL4+6	O
)	O
Empress	B-Application
Embedded	I-Application
Database	I-Application
EXASolution	O
(	O
LDAP	O
)	O
Firebird	B-Application
(	O
Windows	B-Application
trusted	O
authenification	O
)	O
(	O
by	O
custom	O
plugin	O
)	O
(	O
no	O
security	O
page	O
)	O
7	O
HSQLDB	B-Application
H2	B-Language
Informix	B-Application
Dynamic	I-Application
Server	I-Application
10	O
10	O
Linter	B-Application
SQL	I-Application
RDBMS	I-Application
(	O
with	O
SSL	O
)	O
(	O
length	O
only	O
)	O
MariaDB	B-Application
(	O
SSL	O
)	O
(	O
with	O
5.2	O
,	O
but	O
not	O
on	O
Windows	B-Application
servers	O
)	O
8	O
Microsoft	B-Application
SQL	I-Application
Server	I-Application
(	O
Microsoft	O
Active	O
Directory	O
)	O
(	O
From	O
2008	O
)	O
(	O
EAL4+11	O
)	O
Microsoft	B-Operating_System
SQL	I-Operating_System
Server	I-Operating_System
Compact	I-Operating_System
(	O
Embedded	O
Database	O
)	O
(	O
not	O
relevant	O
,	O
only	O
file	O
permissions	O
)	O
(	O
not	O
relevant	O
)	O
(	O
not	O
relevant	O
)	O
(	O
not	O
relevant	O
)	O
(	O
file	O
access	O
)	O
Mimer	B-Application
SQL	I-Application
(	O
depending	O
on	O
OS	O
)	O
MySQL	B-Application
(	O
SSL	O
with	O
4.0	O
)	O
(	O
with	O
5.5	O
,	O
but	O
only	O
in	O
commercial	O
edition	O
)	O
(	O
no	O
security	O
page	O
)	O
8	O
OpenBase	O
SQL	B-Language
(	O
Open	O
Directory	O
,	O
LDAP	O
)	O
OpenLink	B-Application
Virtuoso	I-Application
(	O
optional	O
)	O
(	O
optional	O
)	O
(	O
optional	O
)	O
(	O
optional	O
)	O
(	O
optional	O
)	O
Oracle	B-General_Concept
(	O
EAL21	O
)	O
Actian	O
Zen	O
(	O
PSQL	O
)	O
12	O
Polyhedra	B-Application
DBMS	I-Application
(	O
with	O
SSL	O
.	O
</s>
<s>
Note	O
(	O
7	O
)	O
:	O
FirebirdSQL	B-Application
seems	O
to	O
only	O
have	O
SYSDBA	O
user	O
and	O
DB	O
owner	O
.	O
</s>
<s>
Note	O
(	O
10	O
)	O
:	O
Informix	B-Application
Dynamic	I-Application
Server	I-Application
supports	O
PAM	O
and	O
other	O
configurable	O
authentication	O
.	O
</s>
<s>
Note	O
(	O
13	O
)	O
:	O
User-based	O
security	O
is	O
optional	O
in	O
Polyhedra	B-Application
,	O
but	O
when	O
enabled	O
can	O
be	O
enhanced	O
to	O
a	O
role-based	O
model	O
with	O
auditing	O
.	O
</s>
<s>
The	O
SQL	B-Language
specification	O
defines	O
what	O
an	O
"	O
SQL	B-Language
schema	O
"	O
is	O
;	O
however	O
,	O
databases	O
implement	O
it	O
differently	O
.	O
</s>
<s>
An	O
SQL	B-Language
schema	O
is	O
simply	O
a	O
namespace	O
within	O
a	O
database	O
;	O
things	O
within	O
this	O
namespace	O
are	O
addressed	O
using	O
the	O
member	O
operator	O
dot	O
"	O
.	O
"	O
.	O
</s>
<s>
Both	O
a	O
schema	O
and	O
a	O
database	O
can	O
be	O
used	O
to	O
isolate	O
one	O
table	B-Application
,	O
"	O
foo	O
"	O
,	O
from	O
another	O
like-named	O
table	B-Application
"	O
foo	O
"	O
.	O
</s>
<s>
The	O
problem	O
that	O
arises	O
is	O
that	O
former	O
MySQL	B-Application
users	O
will	O
create	O
multiple	O
databases	O
for	O
one	O
project	O
.	O
</s>
<s>
In	O
this	O
context	O
,	O
MySQL	B-Application
databases	O
are	O
analogous	O
in	O
function	O
to	O
PostgreSQL-schemas	O
,	O
insomuch	O
as	O
PostgreSQL	B-Application
deliberately	O
lacks	O
off-the-shelf	O
cross-database	O
functionality	O
(	O
preferring	O
multi-tenancy	O
)	O
that	O
MySQL	B-Application
has	O
.	O
</s>
<s>
Conversely	O
,	O
PostgreSQL	B-Application
has	O
applied	O
more	O
of	O
the	O
specification	O
implementing	O
cross-table	O
,	O
cross-schema	O
,	O
and	O
then	O
left	O
room	O
for	O
future	O
cross-database	O
functionality	O
.	O
</s>
<s>
MySQL	B-Application
aliases	O
schema	O
with	O
database	O
behind	O
the	O
scenes	O
,	O
such	O
that	O
CREATE	O
SCHEMA	O
and	O
CREATE	O
DATABASE	O
are	O
analogs	O
.	O
</s>
<s>
It	O
can	O
therefore	O
be	O
said	O
that	O
MySQL	B-Application
has	O
implemented	O
cross-database	O
functionality	O
,	O
skipped	O
schema	O
functionality	O
entirely	O
,	O
and	O
provided	O
similar	O
functionality	O
into	O
their	O
implementation	O
of	O
a	O
database	O
.	O
</s>
<s>
In	O
summary	O
,	O
PostgreSQL	B-Application
fully	O
supports	O
schemas	O
and	O
multi-tenancy	O
by	O
strictly	O
separating	O
databases	O
from	O
each	O
other	O
and	O
thus	O
lacks	O
some	O
functionality	O
MySQL	B-Application
has	O
with	O
databases	O
,	O
while	O
MySQL	B-Application
does	O
not	O
even	O
attempt	O
to	O
support	O
standard	O
schemas	O
.	O
</s>
<s>
Oracle	B-General_Concept
has	O
its	O
own	O
spin	O
where	O
creating	O
a	O
user	O
is	O
synonymous	O
with	O
creating	O
a	O
schema	O
.	O
</s>
<s>
Thus	O
a	O
database	O
administrator	O
can	O
create	O
a	O
user	O
called	O
PROJECT	O
and	O
then	O
create	O
a	O
table	B-Application
PROJECT.TABLE	O
.	O
</s>
<s>
With	O
the	O
'	O
shared-everything	O
'	O
Oracle	B-Operating_System
RAC	I-Operating_System
architecture	O
,	O
the	O
same	O
database	O
can	O
be	O
opened	O
by	O
multiple	O
servers	O
concurrently	O
.	O
</s>
<s>
In	O
the	O
Oracle	B-General_Concept
implementation	O
,	O
a	O
'	O
database	O
 '	O
is	O
a	O
set	O
of	O
files	O
which	O
contains	O
the	O
data	O
while	O
the	O
'	O
instance	O
 '	O
is	O
a	O
set	O
of	O
processes	O
(	O
and	O
memory	O
)	O
through	O
which	O
a	O
database	O
is	O
accessed	O
.	O
</s>
<s>
Informix	B-Application
supports	O
multiple	O
databases	O
in	O
a	O
server	O
instance	O
like	O
MySQL	B-Application
.	O
</s>
<s>
It	O
supports	O
the	O
CREATE	O
SCHEMA	O
syntax	O
as	O
a	O
way	O
to	O
group	O
DDL	B-Language
statements	O
into	O
a	O
single	O
unit	O
creating	O
all	O
objects	O
created	O
as	O
a	O
part	O
of	O
the	O
schema	O
as	O
a	O
single	O
owner	O
.	O
</s>
<s>
Informix	B-Application
supports	O
a	O
database	O
mode	O
called	O
ANSI	O
mode	O
which	O
supports	O
creating	O
objects	O
with	O
the	O
same	O
name	O
but	O
owned	O
by	O
different	O
users	O
.	O
</s>
<s>
PostgreSQL	B-Application
and	O
some	O
other	O
databases	O
have	O
support	O
for	O
foreign	O
schemas	O
,	O
which	O
is	O
the	O
ability	O
to	O
import	O
schemas	O
from	O
other	O
servers	O
as	O
defined	O
in	O
ISO/IEC	B-Language
9075-9	I-Language
(	O
published	O
as	O
part	O
of	O
SQL:2008	B-Language
)	O
.	O
</s>
<s>
This	O
appears	O
like	O
any	O
other	O
schema	O
in	O
the	O
database	O
according	O
to	O
the	O
SQL	B-Language
specification	O
while	O
accessing	O
data	O
stored	O
either	O
in	O
a	O
different	O
database	O
or	O
a	O
different	O
server	O
instance	O
.	O
</s>
<s>
While	O
support	O
for	O
ISO/IEC	B-Language
9075-9	I-Language
bridges	O
the	O
gap	O
between	O
the	O
two	O
competing	O
philosophies	O
surrounding	O
schemas	O
,	O
MySQL	B-Application
and	O
Informix	B-Application
maintain	O
an	O
implicit	O
association	O
between	O
databases	O
while	O
ISO/IEC	B-Language
9075-9	I-Language
requires	O
that	O
any	O
such	O
linkages	O
be	O
explicit	O
in	O
nature	O
.	O
</s>
