Is "connect by" equivalent to "recursive with" (was Re: Is nonlinear recursion...)

"Serge Rielau" <srielau_at_ca.eye-be-em.com> wrote in message news:c1j058$i6i$1_at_hanover.torolab.ibm.com...
> You should post in oracle.server

Not sure what is the best oracle place for SQL questions: I thought that "server" is occupied by masters of segments and extents. I'm certain neither group can spell "Datalog" anyway.

Anyway, here is the latest about same generation. Example from the Page 312 of the Alice Book

rsg(x,y) <- flat(x,y)
rsg(x,y) <- up(x,x1),rsg(y1,x1),down(y1,y)

looks very challenging for "connect by".

However, let

up^*(x,y,n)

and

down^*(x,y,n)

be transitive closure of up(x,y), and down(x,y), correspondingly, where n is the length of the path (so that if you have 2 paths of different lenght connecting x and y, then you have 2 tuples in up^* relation). Then,

rsg(x,y) <- up^*(x,x1,n1),flat(y1,x1),down^*(y1,y,n2),n1=n2

which is no-brainer for "connect by".

Therefore, the question still is "Is connect-by less expressive than recursive-with"? Received on Thu Feb 26 2004 - 01:50:13 CET