<s>
MEMORY	O
is	O
a	O
storage	B-General_Concept
engine	I-General_Concept
for	O
MySQL	B-Application
and	O
MariaDB	B-Application
relational	B-Application
database	I-Application
management	I-Application
systems	I-Application
,	O
developed	O
by	O
Oracle	B-Application
and	O
MariaDB	B-Application
.	O
</s>
<s>
Before	O
the	O
version	O
4.1	O
of	O
MySQL	B-Application
it	O
was	O
called	O
Heap	O
.	O
</s>
<s>
While	O
the	O
table	O
structures	O
are	O
persisted	O
on-disk	O
,	O
the	O
rows	O
in	O
MEMORY	O
tables	O
are	O
lost	O
when	O
MySQL	B-Application
stops	O
.	O
</s>
<s>
In	O
MariaDB	B-Application
and	O
before	O
MySQL	O
5.6	O
,	O
MEMORY	O
was	O
used	O
for	O
internal	O
temporary	O
tables	O
,	O
e.g.	O
</s>
<s>
For	O
this	O
reason	O
Percona	B-Application
Server	I-Application
implemented	O
improvements	O
to	O
MEMORY	O
to	O
support	O
BLOB	O
and	O
TEXT	O
.	O
</s>
<s>
In	O
MySQL	B-Application
8.0	O
,	O
by	O
default	O
the	O
TempTable	O
engine	O
is	O
used	O
in	O
place	O
of	O
MEMORY	O
for	O
internal	O
temporary	O
tables	O
.	O
</s>
