<s>
Data	B-Operating_System
Access	I-Operating_System
Language	I-Operating_System
for	O
the	O
Macintosh	O
,	O
or	O
simply	O
DAL	O
,	O
was	O
a	O
SQL-like	O
language	O
and	O
application	B-Application
programming	I-Application
interface	I-Application
released	O
by	O
Apple	O
Computer	O
in	O
1990	O
to	O
provide	O
unified	O
client/server	B-Operating_System
access	O
to	O
database	B-Application
management	I-Application
systems	I-Application
.	O
</s>
<s>
DAL	O
is	O
used	O
as	O
the	O
native	O
SQL	B-Language
dialect	O
of	O
the	O
PrimeBase	B-Application
SQL	B-Language
server	O
,	O
as	O
well	O
as	O
the	O
now-defunct	O
Butler	B-Application
SQL	I-Application
.	O
</s>
<s>
Apple	O
purchased	O
the	O
company	O
in	O
1988	O
,	O
during	O
a	O
time	O
that	O
client/server	B-Operating_System
databases	B-Application
were	O
becoming	O
a	O
hot	O
issue	O
in	O
the	O
industry	O
.	O
</s>
<s>
They	O
released	O
their	O
first	O
version	O
of	O
the	O
re-branded	O
software	O
in	O
1989	O
,	O
for	O
MVS	B-Application
,	O
and	O
followed	O
with	O
other	O
versions	O
over	O
the	O
next	O
year	O
or	O
so	O
.	O
</s>
<s>
DAL	O
's	O
release	O
was	O
also	O
coincident	O
with	O
Apple	O
's	O
fall	O
from	O
grace	O
in	O
the	O
business	O
world	O
,	O
and	O
not	O
coincidentally	O
with	O
Microsoft	O
's	O
ODBC	B-Application
efforts	O
.	O
</s>
<s>
DAL	O
appears	O
to	O
have	O
seen	O
little	O
use	O
,	O
and	O
eventually	O
Apple	O
sold	O
it	O
to	O
Independence	O
Technologies	O
in	O
1994	O
,	O
during	O
a	O
sell-off	O
of	O
a	O
number	O
of	O
"	O
high-end	O
"	O
packages	O
such	O
as	O
their	O
X.400	B-Protocol
server	O
and	O
an	O
SNA	B-Architecture
client	O
.	O
</s>
<s>
Independence	O
Technologies	O
was	O
a	O
middleware	B-General_Concept
vendor	O
,	O
better	O
known	O
as	O
a	O
major	O
reseller	O
of	O
the	O
Tuxedo	B-Application
product	O
for	O
Unix	B-Application
.	O
</s>
<s>
Like	O
Oracle	B-Application
's	O
PL/SQL	B-Language
or	O
Microsoft	O
's	O
Transact-SQL	B-Language
,	O
DAL	O
is	O
essentially	O
an	O
extended	O
version	O
of	O
SQL	B-Language
supporting	O
basic	O
query	O
functionality	O
and	O
adding	O
clean	O
syntax	O
for	O
cursor	O
operations	O
,	O
logic	O
,	O
and	O
loops	O
.	O
</s>
<s>
This	O
translation	O
took	O
place	O
on	O
the	O
server-side	O
,	O
just	O
like	O
PL/SQL	B-Language
and	O
Transact-SQL	B-Language
,	O
but	O
required	O
a	O
fairly	O
expensive	O
"	O
adaptor	O
"	O
program	O
of	O
often	O
dubious	O
performance	O
.	O
</s>
<s>
This	O
adaptor	O
made	O
DAL	O
considerably	O
less	O
appealing	O
than	O
later	O
systems	O
like	O
ODBC	B-Application
,	O
where	O
the	O
translation	O
normally	O
takes	O
place	O
on	O
the	O
client	O
side	O
and	O
is	O
typically	O
included	O
for	O
free	O
with	O
the	O
database	O
engine	O
.	O
</s>
<s>
The	O
downside	O
to	O
the	O
ODBC	B-Application
approach	O
is	O
that	O
,	O
theoretically	O
at	O
least	O
,	O
more	O
network	O
bandwidth	O
is	O
used	O
up	O
to	O
pull	O
the	O
"	O
raw	O
data	O
"	O
to	O
the	O
client	O
machine	O
for	O
processing	O
back	O
into	O
a	O
standard	O
format	O
.	O
</s>
<s>
On	O
the	O
client	O
end	O
,	O
DAL	O
was	O
originally	O
accessed	O
directly	O
through	O
a	O
system	B-Operating_System
extension	I-Operating_System
(	O
named	O
simply	O
"	O
DAL	O
"	O
in	O
System	O
7	O
)	O
,	O
but	O
it	O
was	O
later	O
rolled	O
into	O
a	O
single	O
ODBC-like	O
driver	O
layer	O
,	O
the	O
Data	B-Operating_System
Access	I-Operating_System
Manager	I-Operating_System
(	O
DAM	O
)	O
.	O
</s>
<s>
DAM	O
was	O
ODBC-like	O
in	O
concept	O
,	O
but	O
did	O
not	O
include	O
the	O
SQL	B-Language
layers	O
,	O
it	O
was	O
strictly	O
a	O
system	O
for	O
sending	O
"	O
opaque	O
"	O
queries	O
and	O
receiving	O
result	O
sets	O
.	O
</s>
<s>
One	O
of	O
the	O
more	O
common	O
clients	O
for	O
DAM	O
was	O
HyperCard	B-Application
.	O
</s>
<s>
The	O
combination	O
of	O
HyperCard	B-Application
and	O
DAL	O
presented	O
a	O
serious	O
challenge	O
to	O
existing	O
vendors	O
who	O
could	O
offer	O
nothing	O
with	O
a	O
GUI	O
.	O
</s>
<s>
Apple	O
gave	O
a	O
series	O
of	O
demos	O
of	O
HyperCard/DAL	O
,	O
and	O
soon	O
Oracle	B-Application
Corporation	I-Application
purchased	O
a	O
HyperCard-clone	O
,	O
PLUS	B-Application
from	O
Spinnaker	O
Software	O
,	O
to	O
produce	O
Oracle	B-Application
Card	I-Application
.	O
</s>
<s>
For	O
much	O
of	O
the	O
1990s	O
a	O
direct-DAL	O
database	O
server	O
was	O
available	O
on	O
the	O
Macintosh	O
,	O
Butler	B-Application
SQL	I-Application
.	O
</s>
<s>
However	O
,	O
like	O
any	O
server	O
software	O
on	O
the	O
"	O
classic	O
"	O
Mac	O
OS	O
,	O
Butler	O
was	O
seriously	O
hampered	O
by	O
the	O
Mac	O
's	O
single-user	O
file	B-Application
system	I-Application
and	O
limited	O
multitasking	B-Operating_System
and	O
could	O
never	O
really	O
deliver	O
the	O
sort	O
of	O
performance	O
the	O
same	O
server	O
would	O
have	O
on	O
Windows	B-Device
NT	I-Device
or	O
Unix	B-Application
.	O
</s>
<s>
The	O
PrimeBase	B-Application
division	O
of	O
German	O
software	O
developer	O
SNAP	O
Innovation	O
GmbH	O
continues	O
to	O
support	O
DAL	O
in	O
their	O
cross	O
platform	O
SQL	B-Language
database	I-Language
server	O
(	O
originally	O
known	O
as	O
P.INK	O
SQL	B-Language
)	O
.	O
</s>
<s>
Their	O
architecture	O
does	O
not	O
include	O
Data	B-Operating_System
Access	I-Operating_System
Manager	I-Operating_System
and	O
the	O
resulting	O
performance	O
gains	O
are	O
considerable	O
.	O
</s>
