<s>
A	O
cuckoo	B-Algorithm
filter	I-Algorithm
is	O
a	O
space-efficient	O
probabilistic	O
data	B-General_Concept
structure	I-General_Concept
that	O
is	O
used	O
to	O
test	O
whether	O
an	O
element	O
is	O
a	O
member	O
of	O
a	O
set	O
,	O
like	O
a	O
Bloom	B-Algorithm
filter	I-Algorithm
does	O
.	O
</s>
<s>
not	O
supported	O
by	O
Bloom	B-Algorithm
filters	I-Algorithm
.	O
</s>
<s>
lower	O
space	O
overhead	O
than	O
space-optimized	O
Bloom	B-Algorithm
filters	I-Algorithm
.	O
</s>
<s>
Cuckoo	B-Algorithm
filters	I-Algorithm
were	O
first	O
described	O
in	O
2014	O
.	O
</s>
<s>
A	O
cuckoo	B-Algorithm
filter	I-Algorithm
uses	O
a	O
-way	O
set-associative	O
hash	O
table	O
based	O
on	O
cuckoo	B-Algorithm
hashing	I-Algorithm
to	O
store	O
the	O
fingerprints	B-Algorithm
of	O
all	O
items	O
(	O
every	O
bucket	O
of	O
the	O
hashtable	O
can	O
store	O
up	O
to	O
entries	O
)	O
.	O
</s>
<s>
(	O
termed	O
as	O
partial-key	O
cuckoo	B-Algorithm
hashing	I-Algorithm
)	O
:	O
</s>
<s>
Based	O
on	O
partial-key	O
cuckoo	B-Algorithm
hashing	I-Algorithm
,	O
the	O
hash	O
table	O
can	O
achieve	O
both	O
high	O
utilization	O
(	O
thanks	O
to	O
cuckoo	B-Algorithm
hashing	I-Algorithm
)	O
,	O
</s>
<s>
and	O
compactness	O
because	O
only	O
fingerprints	B-Algorithm
are	O
stored	O
.	O
</s>
<s>
Lookup	O
and	O
delete	O
operations	O
of	O
a	O
cuckoo	B-Algorithm
filter	I-Algorithm
are	O
straightforward	O
.	O
</s>
<s>
More	O
theoretical	O
analysis	O
of	O
cuckoo	B-Algorithm
filters	I-Algorithm
can	O
be	O
found	O
in	O
the	O
literature	O
.	O
</s>
<s>
A	O
cuckoo	B-Algorithm
filter	I-Algorithm
is	O
similar	O
to	O
a	O
Bloom	B-Algorithm
filter	I-Algorithm
in	O
that	O
they	O
both	O
are	O
very	O
fast	O
and	O
compact	O
,	O
</s>
<s>
Space-optimal	O
Bloom	B-Algorithm
filters	I-Algorithm
use	O
bits	O
of	O
space	O
per	O
inserted	O
key	O
,	O
where	O
is	O
the	O
false	O
positive	O
rate	O
.	O
</s>
<s>
A	O
cuckoo	B-Algorithm
filter	I-Algorithm
requires	O
where	O
is	O
the	O
hash	O
table	O
load	O
factor	O
,	O
which	O
can	O
be	O
based	O
on	O
the	O
cuckoo	B-Algorithm
filter	I-Algorithm
's	O
setting	O
.	O
</s>
<s>
Both	O
bloom	B-Algorithm
filters	I-Algorithm
and	O
cuckoo	B-Algorithm
filters	I-Algorithm
with	O
low	O
load	O
can	O
be	O
compressed	O
when	O
not	O
in	O
use	O
.	O
</s>
<s>
On	O
a	O
positive	O
lookup	O
,	O
a	O
space-optimal	O
Bloom	B-Algorithm
filter	I-Algorithm
requires	O
a	O
constant	O
memory	O
accesses	O
into	O
the	O
bit	O
array	O
,	O
whereas	O
a	O
cuckoo	B-Algorithm
filter	I-Algorithm
requires	O
constant	O
two	O
lookups	O
at	O
most	O
.	O
</s>
<s>
Cuckoo	B-Algorithm
filters	I-Algorithm
have	O
degraded	O
insertion	O
speed	O
after	O
reaching	O
a	O
load	O
threshold	O
,	O
when	O
table	O
expanding	O
is	O
recommended	O
.	O
</s>
<s>
In	O
contrast	O
,	O
Bloom	B-Algorithm
filters	I-Algorithm
can	O
keep	O
inserting	O
new	O
items	O
at	O
the	O
cost	O
of	O
a	O
higher	O
false	O
positive	O
rate	O
before	O
expansion	O
.	O
</s>
<s>
Bloom	B-Algorithm
filters	I-Algorithm
offer	O
fast	O
union	O
and	O
approximate	O
intersection	O
operations	O
using	O
cheap	O
bitwise	O
operations	O
,	O
which	O
can	O
also	O
be	O
applied	O
to	O
compressed	O
bloom	B-Algorithm
filters	I-Algorithm
if	O
streaming	O
compression	O
is	O
used	O
.	O
</s>
<s>
A	O
cuckoo	B-Algorithm
filter	I-Algorithm
can	O
only	O
delete	O
items	O
that	O
are	O
known	O
to	O
be	O
inserted	O
before	O
.	O
</s>
<s>
Insertion	O
can	O
fail	O
and	O
rehashing	O
is	O
required	O
like	O
other	O
cuckoo	B-Algorithm
hash	I-Algorithm
tables	I-Algorithm
.	O
</s>
