<s>
Comdb2	B-Application
is	O
an	O
open	B-License
source	I-License
,	O
highly	O
available	O
clustered	O
RDBMS	B-Application
developed	O
by	O
Bloomberg	O
LP	O
,	O
built	O
on	O
optimistic	B-Operating_System
concurrency	I-Operating_System
control	I-Operating_System
techniques	O
.	O
</s>
<s>
It	O
provides	O
multiple	O
isolation	B-General_Concept
levels	I-General_Concept
,	O
including	O
Snapshot	O
and	O
Serializable	O
Isolation	B-General_Concept
.	O
</s>
<s>
Comdb2	B-Application
implements	O
queues	O
for	O
publisher-to-subscriber	O
message	O
delivery	O
.	O
</s>
<s>
Comdb2	B-Application
supports	O
the	O
SQLite	B-Language
dialect	O
of	O
SQL	B-Language
with	O
some	O
modifications	O
,	O
and	O
embeds	O
the	O
Lua	B-Language
scripting	I-Language
language	I-Language
.	O
</s>
<s>
Comdb2	B-Application
maintains	O
a	O
fork	O
of	O
Berkeley	B-Language
DB	I-Language
to	O
provide	O
the	O
key	B-Data_Structure
–	I-Data_Structure
value	I-Data_Structure
database	I-Data_Structure
backend	O
to	O
SQLite	B-Language
.	O
</s>
<s>
Comdb2	B-Application
architecture	O
was	O
described	O
in	O
detail	O
in	O
this	O
2016	O
technical	O
paper	O
.	O
</s>
