What's a transitive closure? On Thu, Jun 10, 2010 at 2:34 PM, Gianmarco <[email protected]> wrote:
> I think what he wants is a transitive closure of the relation, which > is not achievable in SQL-like languages alone (first order logic > expressive power). > I suppose Pig Latin falls in this category. > > > -- Gianmarco > > On Thu, Jun 10, 2010 at 19:54, hc busy <[email protected]> wrote: > > Is this like a tricky interview question? I don't see the pattern between > > those three numbers you listed and the sample of the table. > > > > 770011 770083 524 1e-120 89 12 > > 770083 770011 494 1e-120 39 100 > > > > ahh, I guess these are related because id1=id2 an id2=id1... Here's a > first > > pass at the problem. Project: > > > > P1 = foreach table generate id1 as id1, id2 as id2, *; > > P2 = foreach table generate id2 as id1, id1 as id2, *; > > J = join P1 by (id1, id2), P2 by (id1,id2); > > > > and now J contains pairs of rows from original table where id1 and id2 > are > > reversed. > > > > is this what you want? > > > > On Wed, Jun 9, 2010 at 6:54 PM, Renato Marroquín Mogrovejo < > > [email protected]> wrote: > > > >> Hi everyone, today I came across with a particular query that I don't > know > >> how to model in PIG. Part of my data looks like this: > >> > >> Id1 Id2 Sc Va P1 P2 > >> --------- --------- ----- --------- ----- ---- > >> 770011 990201 401 1e-125 100 65 > >> 990201 770011 440 1e-125 100 42 > >> 770011 770083 524 1e-120 89 12 > >> 770083 770011 494 1e-120 39 100 > >> 990201 770083 341 1e-125 73 41 > >> 770083 990201 421 1e-125 90 85 > >> . > >> . > >> . > >> > >> what I would like to retrieve is something like > >> this: 770011 990201 770083 > >> because they are records actually related. > >> Any kind of ideas are highly appreciated. Thanks in advanced. > >> > >> Renato M. > >> > > >
