On Thu, 15 Dec 2005, Luke Palmer wrote:
On 12/15/05, Darren Duncan <[EMAIL PROTECTED]> wrote:
I propose, perhaps redundantly, that Perl 6 include a complete set of
native
Okay, I'm with you here. Just please stop saying "native" and "core".
Everyone.
Here, here.
I would like to hear from Ovid and Dave Rolsky on this issue too, as
they seem to have been researching pure relational models.
My take on this is that with all the features that are supposed to be in
Perl6, implementing a declarative mini-language for relations and tuples
would be a simple matter of programming ;)
The following bits seem to me to be key to making this work:
* built-in set operators, which can presumably be overloaded
* powerful OO system
* optional strong typing
* macros and grammar engine
So we can do stuff like this:
my $emp_rel = Relation.new_from_dbms('Employee');
my $dep_rel = Relation.new_from_dbms('Department');
my $emp_dep_rel = $emp_rel natural join $dep_rel; # natural join is a macro of
some sort
my @array = $emp_dep_rel.sorted_tuples($emp_rel.attribute('name'));
This is a kind of bastardized semi-logical semi-OO language, but
presumably we could do this instead
my $relation = relational($dbh, <<EOF);
( ( Employee RENAME name AS employee_name ) NATURAL JOIN ( Department
RENAME name AS department_name ) )
WHERE X.department_name = 'Management'
EOF
And then presumably the Perl-side of the implementation will have some
sort of object that does relational things, like:
my $iterator = $relation.iterator( sort => 'employee_name' );
In fact, there's really no reason this couldn't be done in Perl5 today.
The hard part is gluing the Perl bits to a DBMS, or alternatively
implementing all of the relational logic (and therefore an RDBMS) in Perl.
Given that there is no truly relational DBMS available, I'm not sure
exactly what Perl6 can do here, as the hard part is implementing such a
that TRDBMS. Of course, you could implement one client-side on top of a
SQL DBMS. It's just a simple matter of programming ;)
-dave
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