<s>
Oracle	B-Application
TimesTen	I-Application
In-Memory	I-Application
Database	I-Application
is	O
an	O
in-memory	B-General_Concept
,	O
relational	B-Application
database	I-Application
management	I-Application
system	I-Application
with	O
persistence	O
and	O
high	O
availability	O
.	O
</s>
<s>
Originally	O
designed	O
and	O
implemented	O
at	O
Hewlett-Packard	O
labs	O
in	O
Palo	O
Alto	O
,	O
California	O
,	O
TimesTen	B-Application
spun	O
out	O
into	O
a	O
separate	O
startup	O
in	O
1996	O
and	O
was	O
acquired	O
by	O
Oracle	B-Application
Corporation	I-Application
in	O
2005	O
.	O
</s>
<s>
TimesTen	B-Application
databases	O
are	O
persistent	O
and	O
can	O
be	O
highly	O
available	O
.	O
</s>
<s>
Because	O
it	O
is	O
an	O
in-memory	B-General_Concept
database	I-General_Concept
it	O
provides	O
very	O
low	O
latency	O
and	O
high	O
throughput	O
.	O
</s>
<s>
It	O
provides	O
standard	O
relational	O
database	O
APIs	O
and	O
interfaces	O
such	O
as	O
the	O
SQL	B-Language
and	O
PL/SQL	B-Language
languages	O
.	O
</s>
<s>
Applications	O
access	O
TimesTen	B-Application
using	O
standard	O
database	O
APIs	O
such	O
as	O
ODBC	B-Application
and	O
JDBC	B-Language
.	O
</s>
<s>
TimesTen	B-Application
can	O
be	O
used	O
as	O
a	O
standalone	O
database	O
,	O
and	O
is	O
also	O
often	O
used	O
as	O
a	O
cache	O
in	O
front	O
of	O
another	O
relational	O
database	O
such	O
as	O
Oracle	B-General_Concept
Database	I-General_Concept
.	O
</s>
<s>
It	O
is	O
frequently	O
used	O
in	O
very	O
high	O
volume	O
OLTP	B-General_Concept
applications	O
such	O
as	O
prepaid	O
telecom	O
billing	O
and	O
financial	O
trading	O
.	O
</s>
<s>
TimesTen	B-Application
can	O
be	O
configured	O
as	O
a	O
shared-nothing	B-Operating_System
clustered	O
system	O
(	O
TimesTen	B-Application
Scaleout	O
)	O
supporting	O
databases	O
much	O
larger	O
than	O
the	O
RAM	B-Architecture
available	O
on	O
a	O
single	O
machine	O
,	O
and	O
providing	O
scalable	O
throughput	O
and	O
high	O
availability	O
.	O
</s>
<s>
It	O
can	O
also	O
be	O
configured	O
in	O
replicated	O
active/standby	O
pairs	O
of	O
databases	O
(	O
TimesTen	B-Application
Classic	O
)	O
providing	O
high	O
availability	O
and	O
microsecond	O
response	O
time	O
.	O
</s>
<s>
TimesTen	B-Application
runs	O
on	O
Linux	B-Application
,	O
Solaris	B-Application
and	O
AIX	B-Application
and	O
also	O
supports	O
client	O
applications	O
running	O
on	O
Windows	B-Application
and	O
macOS	B-Application
.	O
</s>
<s>
TimesTen	B-Application
is	O
an	O
in-memory	B-General_Concept
database	I-General_Concept
that	O
provides	O
very	O
fast	O
data	O
access	O
time	O
.	O
</s>
<s>
It	O
ensures	O
that	O
all	O
data	O
will	O
reside	O
in	O
physical	O
memory	O
(	O
RAM	B-Architecture
)	O
during	O
run	O
time	O
.	O
</s>
<s>
TimesTen	B-Application
can	O
make	O
use	O
of	O
available	O
RAM	B-Architecture
available	O
on	O
its	O
host	O
machine	O
,	O
up	O
to	O
terabytes	O
in	O
size	O
;	O
using	O
TimesTen	B-Application
Scaleout	O
databases	O
much	O
larger	O
than	O
the	O
RAM	B-Architecture
of	O
a	O
single	O
machine	O
are	O
supported	O
.	O
</s>
<s>
TimesTen	B-Application
supports	O
standard	O
relational	O
database	O
concepts	O
.	O
</s>
<s>
Data	O
is	O
manipulated	O
using	O
SQL	B-Language
.	O
</s>
<s>
Transactions	O
allow	O
data	O
to	O
be	O
manipulated	O
with	O
appropriate	O
levels	O
of	O
atomicity	O
and	O
isolation	O
;	O
TimesTen	B-Application
supports	O
all	O
standard	O
ACID	O
properties	O
expected	O
of	O
relational	O
databases	O
.	O
</s>
<s>
Datatypes	O
supported	O
by	O
TimesTen	B-Application
are	O
in	O
general	O
a	O
subset	O
of	O
those	O
supported	O
by	O
Oracle	B-General_Concept
Database	I-General_Concept
,	O
including	O
NUMBER	O
,	O
VARCHAR	O
and	O
LOBs	O
;	O
TimesTen	B-Application
specific	O
datatypes	O
such	O
as	O
binary	O
integers	O
are	O
also	O
supported	O
.	O
</s>
<s>
Applications	O
access	O
TimesTen	B-Application
databases	O
using	O
standard	O
relational	O
APIs	O
such	O
as	O
ODBC	B-Application
,	O
JDBC	B-Language
,	O
OCI	O
,	O
and	O
ODPI-C	O
.	O
</s>
<s>
Applications	O
use	O
those	O
APIs	O
to	O
access	O
and	O
manipulate	O
data	O
using	O
standard	O
SQL	B-Language
.	O
</s>
<s>
Stored	O
procedures	O
can	O
also	O
be	O
implemented	O
and	O
executed	O
using	O
PL/SQL	B-Language
.	O
</s>
<s>
Though	O
an	O
in-memory	B-General_Concept
database	I-General_Concept
,	O
TimesTen	B-Application
databases	O
are	O
persistent	O
and	O
can	O
be	O
highly	O
available	O
.	O
</s>
<s>
At	O
runtime	O
all	O
TimesTen	B-Application
data	O
is	O
in	O
RAM	B-Architecture
,	O
however	O
TimesTen	B-Application
utilizes	O
non-volatile	O
storage	O
for	O
database	O
persistence	O
and	O
recoverability	O
.	O
</s>
<s>
TimesTen	B-Application
stores	O
snapshots	O
of	O
the	O
database	O
,	O
called	O
checkpoint	O
files	O
,	O
in	O
a	O
local	O
filesystem	O
.	O
</s>
<s>
The	O
combination	O
of	O
checkpoint	O
files	O
and	O
transaction	O
log	O
files	O
allow	O
TimesTen	B-Application
to	O
recover	O
the	O
database	O
in	O
the	O
event	O
of	O
a	O
system	O
failure	O
.	O
</s>
<s>
In	O
addition	O
TimesTen	B-Application
databases	O
can	O
be	O
replicated	O
to	O
multiple	O
machines	O
to	O
provide	O
for	O
high	O
availability	O
and	O
disaster	O
recovery	O
.	O
</s>
<s>
Applications	O
may	O
connect	O
to	O
TimesTen	B-Application
databases	O
either	O
in	O
a	O
traditional	O
client/server	O
manner	O
using	O
TCP/IP	O
as	O
the	O
underlying	O
transport	O
or	O
in	O
direct	O
mode	O
.	O
</s>
<s>
Direct	O
mode	O
allows	O
applications	O
running	O
on	O
the	O
same	O
machine	O
as	O
the	O
database	O
to	O
avoid	O
network	O
stack	O
and	O
context	B-Operating_System
switching	I-Operating_System
overheads	O
.	O
</s>
<s>
At	O
runtime	O
the	O
data	O
in	O
a	O
TimesTen	B-Application
database	O
is	O
stored	O
in	O
shared	B-Operating_System
memory	I-Operating_System
;	O
this	O
allows	O
application	O
processes	O
to	O
directly	O
attach	O
to	O
the	O
database	O
memory	O
and	O
access	O
it	O
without	O
IPC	B-Operating_System
or	O
context	B-Operating_System
switch	I-Operating_System
overheads	O
.	O
</s>
<s>
Because	O
TimesTen	B-Application
databases	O
are	O
persistent	O
and	O
can	O
provide	O
high	O
availability	O
,	O
they	O
can	O
be	O
used	O
as	O
the	O
only	O
database	O
in	O
many	O
solutions	O
.	O
</s>
<s>
However	O
,	O
TimesTen	B-Application
databases	O
are	O
often	O
used	O
alongside	O
other	O
databases	O
such	O
as	O
Oracle	B-General_Concept
Database	I-General_Concept
,	O
with	O
a	O
TimesTen	B-Application
database	O
serving	O
as	O
a	O
cache	O
for	O
a	O
subset	O
of	O
data	O
in	O
the	O
(	O
perhaps	O
larger	O
)	O
traditional	O
database	O
.	O
</s>
<s>
TimesTen	B-Application
provides	O
the	O
capability	O
to	O
cache	O
data	O
from	O
an	O
Oracle	B-General_Concept
Database	I-General_Concept
source	O
.	O
</s>
<s>
To	O
utilize	O
Oracle	B-General_Concept
Database	I-General_Concept
caching	O
,	O
one	O
defines	O
one	O
or	O
more	O
SQL	B-Language
objects	O
known	O
as	O
cache	O
groups	O
.	O
</s>
<s>
Database	O
tables	O
in	O
a	O
cache	O
group	O
must	O
each	O
have	O
a	O
defined	O
primary	B-Application
key	I-Application
or	O
a	O
unique	O
index	O
declared	O
across	O
a	O
set	O
of	O
non-nullable	O
columns	O
and	O
must	O
be	O
related	O
in	O
a	O
parent-child	O
hierarchy	O
via	O
primary	O
key-foreign	O
key	O
constraints	O
.	O
</s>
<s>
SQL	B-Language
predicates	O
can	O
be	O
used	O
to	O
control	O
what	O
data	O
is	O
to	O
be	O
cached	O
.	O
</s>
<s>
Once	O
a	O
cache	O
group	O
is	O
defined	O
,	O
the	O
cache	O
group	O
can	O
then	O
be	O
"	O
loaded	O
"	O
,	O
allowing	O
Oracle	B-General_Concept
Database	I-General_Concept
data	O
to	O
be	O
cached	O
in	O
TimesTen	B-Application
.	O
</s>
<s>
Applications	O
can	O
then	O
read	O
from	O
and	O
write	O
to	O
cache	O
groups	O
,	O
and	O
all	O
data	O
modifications	O
will	O
then	O
be	O
synchronized	O
with	O
the	O
corresponding	O
Oracle	B-General_Concept
Database	I-General_Concept
tables	O
.	O
</s>
<s>
Other	O
solutions	O
such	O
as	O
Oracle	B-Application
Golden	I-Application
Gate	I-Application
can	O
also	O
be	O
used	O
to	O
synchronize	O
data	O
between	O
TimesTen	B-Application
and	O
other	O
databases	O
,	O
also	O
allowing	O
TimesTen	B-Application
to	O
be	O
used	O
as	O
a	O
very	O
fast	O
cache	O
in	O
front	O
of	O
other	O
databases	O
.	O
</s>
<s>
TimesTen	B-Application
can	O
be	O
configured	O
in	O
two	O
ways	O
,	O
called	O
TimesTen	B-Application
Classic	O
and	O
TimesTen	B-Application
Scaleout	O
.	O
</s>
<s>
TimesTen	B-Application
Classic	O
implements	O
in-memory	B-General_Concept
databases	I-General_Concept
that	O
are	O
implemented	O
on	O
a	O
single	O
machine	O
,	O
but	O
which	O
can	O
be	O
replicated	O
to	O
other	O
machines	O
for	O
high	O
availability	O
.	O
</s>
<s>
Databases	O
provided	O
by	O
TimesTen	B-Application
Classic	O
provide	O
extremely	O
low	O
latency	O
,	O
as	O
queries	O
do	O
not	O
require	O
any	O
network	O
I/O	O
and	O
all	O
data	O
is	O
local	O
.	O
</s>
<s>
The	O
TimesTen	B-Application
Classic	O
replication	O
mechanism	O
enables	O
a	O
highly	O
available	O
system	O
by	O
sending	O
database	O
updates	O
between	O
two	O
or	O
more	O
hosts	O
.	O
</s>
<s>
TimesTen	B-Application
Scaleout	O
allows	O
a	O
single	O
TimesTen	B-Application
database	O
to	O
span	O
many	O
machines	O
.	O
</s>
<s>
A	O
shared-nothing	B-Operating_System
architecture	I-Operating_System
is	O
used	O
to	O
distribute	O
data	O
across	O
multiple	O
TimesTen	B-Application
instances	O
running	O
on	O
many	O
machines	O
.	O
</s>
<s>
Databases	O
provided	O
by	O
TimesTen	B-Application
Scaleout	O
can	O
be	O
larger	O
than	O
the	O
amount	O
of	O
RAM	B-Architecture
available	O
on	O
a	O
single	O
machine	O
,	O
and	O
database	O
throughput	O
is	O
scalable	O
as	O
more	O
machines	O
are	O
added	O
.	O
</s>
<s>
TimesTen	B-Application
was	O
founded	O
in	O
HP	O
labs	O
by	O
Marie-Anne	O
Neimat	O
,	O
Sherry	O
Listgarten	O
,	O
Kurt	O
Shoens	O
and	O
Kevin	O
Wilkerson	O
,	O
under	O
the	O
name	O
of	O
"	O
Smallbase	B-Application
"	O
.	O
</s>
<s>
At	O
HP	O
,	O
Jean-René	O
Bouvier	O
decided	O
to	O
embed	O
Smallbase	B-Application
into	O
HP	B-Application
OpenCall	I-Application
,	O
which	O
made	O
the	O
first	O
commercial	O
use	O
of	O
the	O
product	O
in	O
1995	O
.	O
</s>
<s>
The	O
product	O
became	O
popular	O
for	O
telecommunications	O
equipment	O
,	O
as	O
response	O
times	O
in	O
the	O
milliseconds	O
or	O
even	O
microseconds	O
were	O
required	O
for	O
applications	O
like	O
packet	B-Protocol
switching	O
.	O
</s>
<s>
The	O
company	O
had	O
90	O
employees	O
and	O
was	O
profitable	O
when	O
it	O
was	O
acquired	O
by	O
Oracle	B-Application
Corporation	I-Application
in	O
2005	O
.	O
</s>
<s>
After	O
the	O
acquisition	O
,	O
many	O
Oracle	B-General_Concept
database	I-General_Concept
features	O
were	O
added	O
to	O
TimesTen	B-Application
such	O
as	O
support	O
for	O
PL/SQL	B-Language
and	O
integration	O
with	O
Oracle	B-Operating_System
SQL	I-Operating_System
Developer	I-Operating_System
and	O
Oracle	B-Operating_System
Enterprise	I-Operating_System
Manager	I-Operating_System
.	O
</s>
<s>
TimesTen	B-Application
Scaleout	O
was	O
added	O
in	O
2018	O
.	O
</s>
