- From: Juan Sequeda <juanfederico@gmail.com>
- Date: Thu, 17 Feb 2011 10:10:50 -0600
- To: Alexandre Bertails <bertails@w3.org>
- Cc: public-rdb2rdf-wg@w3.org
- Message-ID: <AANLkTik2Dy9FrdBmRjVDDKX38zbJDfRA2q_o0EiTUGm1@mail.gmail.com>
Is it me, or is the updated version that you are presenting [1] completely
different from the current version [2].
Your proposal is to replace [2] with [1] ?
Thanks for the clarification
[1] http://www.w3.org/2011/02/16-DM-denotational-rdf-semantics
[2] http://www.w3.org/TR/2010/WD-rdb-direct-mapping-20101118/#RDFdef
Juan Sequeda
+1-575-SEQ-UEDA
www.juansequeda.com
On Wed, Feb 16, 2011 at 2:14 PM, Juan Sequeda <juanfederico@gmail.com>wrote:
>
>
> On Wed, Feb 16, 2011 at 1:56 PM, Alexandre Bertails <bertails@w3.org>wrote:
>
>> On Wed, 2011-02-16 at 13:50 -0600, Juan Sequeda wrote:
>> > On Wed, Feb 16, 2011 at 1:26 PM, Alexandre Bertails <bertails@w3.org>
>> > wrote:
>> > Hi Juan,
>> >
>> > On Wed, 2011-02-16 at 13:15 -0600, Juan Sequeda wrote:
>> > > Alex, Eric
>> > >
>> > >
>> > > Can you guys clarify some issues that I'm not understanding
>> > correctly.
>> >
>> >
>> > It's funny you ask these things right after I sent [1] :-)
>> >
>> >
>> >
>> > Yes, what a coincidence. You sent your email 1 hour ago. I've been
>> > working on this for the last two.
>> >
>> > I suggest you follow [2] instead of what you found in the
>> > current draft.
>> > This is an updated version (far simpler and much more
>> > complete) and I'll
>> > be happy to help you going through it.
>> >
>> >
>> > Damn.. 2 hours of work down the drain....
>>
>> Sorry for that :-/
>>
>
> Np. Not your fault ;)
>
>>
>> One good indication of our work is to follow the activity on the
>> repository. We don't produce the maths without having the corresponding
>> code and tests. This part is now living in the "no_hierarchy" branch but
>> I plan to merge that into the default one in the next days. That will
>> also update the web application but this will be transparent, as both
>> branches pass exactly the same test-suite.
>>
>
> ok
>
>>
>> Alexandre.
>>
>>
>> >
>> >
>> > Alexandre Bertails.
>> >
>> > [1] http://www.w3.org/mid/1297880900.11894.25.camel@simplet
>> > [2] http://www.w3.org/2011/02/16-DM-denotational-rdf-semantics
>> >
>> >
>> > >
>> > >
>> > > Thanks!
>> > >
>> > >
>> > > I'm going to use this as my
>> > > example:
>> >
>> http://www.w3.org/TR/2010/WD-rdb-direct-mapping-20101118/#lead-ex
>> > >
>> > >
>> > > First, I'm going to define a Database Model, following:
>> > >
>> > http://www.w3.org/TR/2010/WD-rdb-direct-mapping-20101118/#Rel
>> > >
>> > >
>> > > Database = {"Address -> Table1, "People" -> Table2}
>> > >
>> > >
>> > > Table1 = (Header1, 0, [id], 0, Body1)
>> > > Header1 = {id -> int, city -> char, state ->char}
>> > > Body1 = [Tuple1, Tuple2]
>> > > Tuple1 = {id -> 18, city -> Cambridge, state -> MA}
>> > > Tuple2 = {id -> 19, city -> Austin, state -> TX}
>> > >
>> > >
>> > > Table2 = {Header2, 0, [id], FK2, Body2)
>> > > Header2 = {id -> int, fname -> char, addr -> int}
>> > > FK2 = { [addr] -> (Table1, [id]) }
>> > > Body2 = [Tuple3, Tuple4, Tuple5]
>> > > Tuple3 = {id -> 7, fname -> Bob, addr -> 18}
>> > > Tuple4 = {id -> 8, fname -> Sue, addr -> null}
>> > > Tuple5 = {id -> 9, fname -> Joe, addr -> 19}
>> > >
>> > >
>> > > So lets start!
>> > > [23]
>> > > directDB()
>> > > ≝
>> > > { directR(R, M) ∣
>> > > R ∈ DB }
>> > >
>> > >
>> > > First of all, I do not know what M is. I'm assuming that DB
>> > is the
>> > > Database, therefore:
>> > >
>> > >
>> > > R = {"Address -> Table1, "People" -> Table2}
>> > >
>> > >
>> > > If I understand the notation correctly, then:
>> > >
>> > >
>> > > directDB() = {directR("Address -> Table1, M),
>> > directR("People" ->
>> > > Table2, M)}
>> > >
>> > >
>> > > so let's do the first directR
>> > >
>> > >
>> > > 24]
>> > > directR(R, M)
>> > > ≝
>> > > { directT(T, R,
>> > > M) ∣ T ∈ R.Body }
>> > >
>> > > I'm still unclear what is M
>> > >
>> > >
>> > > What is R.Body? I'm assuming you are retrieving Body.
>> > Therefore Body
>> > > of Table1 is [Tuple1, Tuple2], therefore I assume:
>> > >
>> > >
>> > > T = [Tuple1, Tuple2]
>> > >
>> > >
>> > > now we have:
>> > >
>> > >
>> > > directR("Address -> Table1, M) = { directT([Tuple1, Tuple2],
>> > "Address
>> > > -> Table1, M) }
>> > >
>> > >
>> > > now let's go to the definition of directT
>> > >
>> > >
>> > > 25]
>> > > directT(T, R, M)
>> > > ≝
>> > > { directS(S, T,
>> > > R, M) ∣ S =
>> > > subject(T, R,
>> > > M) }
>> > >
>> > >
>> > > now we need to know what is S
>> > >
>> > >
>> > > 26]
>> > > subject(T, R, M)
>> > > ≝
>> > > if (pk(R) =
>> > > ∅) then new blank
>> > > node else rowIRI(R, T[pk(R)]) # references the ultimate
>> > referent of hierarchical key
>> > >
>> > >
>> > > What is pk(R)?
>> > >
>> > >
>> > > now we have:
>> > >
>> > >
>> > > subject([Tuple1, Tuple2], "Address -> Table1, M) = if
>> > (pk("Address ->
>> > > Table1) = 0
>> > >
>> > > then new blank node
>> > >
>> > > else
>> > >
>> > > rowIRI("Address -> Table1, T[pk("Address ->
>> > Table1)])
>> > >
>> > >
>> > >
>> > >
>> > > I'm assuming tat pk("Address -> Table1) will return the
>> > primary key,
>> > > then we have
>> > >
>> > >
>> > > pk("Address -> Table1) = [id]
>> > >
>> > >
>> > > Now we have
>> > >
>> > >
>> > > subject([Tuple1, Tuple2], "Address -> Table1, M) =
>> > rowIRI("Address ->
>> > > Table1, T[[id]])
>> > >
>> > >
>> > > Now let's go to the definition of rowIRI
>> > >
>> > >
>> > > [31]
>> > > rowIRI(R, As)
>> > > ≝
>> > > IRI(UE(R.name) +
>> > > "/" + (join(',',
>> > > UE(A.name) + "="
>> > > + UE(A.value)) ∣
>> > > A ∈ As ) + "#_")
>> > >
>> > >
>> > > What is UE()?
>> > >
>> > >
>> > > What is R.name? Where is it defined?
>> > >
>> > >
>> > > Ok, I'm stopping here.
>> > >
>> > >
>> > > p.s. By the time I finished doing all of this, I saw that
>> > Alex sent an
>> > > email with a new version of the denotational semantics. I'm
>> > guessing I
>> > > should re-do what I just did with the new version?
>> > >
>> > >
>> > > Thanks guys for the clarifications!
>> > >
>> > >
>> > > Juan Sequeda
>> > > +1-575-SEQ-UEDA
>> > > www.juansequeda.com
>> > >
>> > >
>> >
>> >
>> >
>> >
>>
>>
>>
>
Received on Thursday, 17 February 2011 16:11:44 UTC