Am Samstag, den 04.06.2005, 15:22 -0500 schrieb Bruno Wolff III:
On Sat, Jun 04, 2005 at 21:53:24 +0200,
Joachim Zobel [EMAIL PROTECTED] wrote:
So WITH will allow recursion so I can walk the graph, right? Does this
mean I can recursively join until a terminating condition is reached?
It
Joachim Zobel schrob:
Am Samstag, den 04.06.2005, 15:22 -0500 schrieb Bruno Wolff III:
On Sat, Jun 04, 2005 at 21:53:24 +0200,
Joachim Zobel [EMAIL PROTECTED] wrote:
So WITH will allow recursion so I can walk the graph, right? Does this
mean I can recursively join until a terminating
Am Donnerstag, den 02.06.2005, 12:46 -0700 schrieb Ben:
You mean, you want to be able to say something like:
select isConnected(a,b)
and get back a true/false, or maybe the path?
That seems quite doable in SQL, assuming you either store those results
and simply use sql to retrieve
On Sat, Jun 04, 2005 at 11:31:02 +0200,
Joachim Zobel [EMAIL PROTECTED] wrote:
These are both things I want to avoid. I am not trying to solve a real
world problem, I want to understand the limits of SQL. And it seems that
a plain SELECT that tells me if a path exists is not possible.
Am Samstag, den 04.06.2005, 07:38 -0500 schrieb Bruno Wolff III:
On Sat, Jun 04, 2005 at 11:31:02 +0200,
Joachim Zobel [EMAIL PROTECTED] wrote:
... And it seems that
a plain SELECT that tells me if a path exists is not possible...
When 'WITH' gets implemented then you should be able
On Sat, Jun 04, 2005 at 21:53:24 +0200,
Joachim Zobel [EMAIL PROTECTED] wrote:
Am Samstag, den 04.06.2005, 07:38 -0500 schrieb Bruno Wolff III:
On Sat, Jun 04, 2005 at 11:31:02 +0200,
Joachim Zobel [EMAIL PROTECTED] wrote:
... And it seems that
a plain SELECT that tells me if a
Is anybody else thinking about the limits of SQL? As often I am probably
not the first to ask these questions. Any pointers?
Joe Celko (sp?) has a couple of books on this subject, SQL for Smarties. I
don't recall if he talks about graphs, but does discuss queries on tree
relationships.
--
Is anybody else thinking about the limits of SQL? As often I am probably
not the first to ask these questions. Any pointers?
Joe Celko (sp?) has a couple of books on this subject, SQL for Smarties. I
don't recall if he talks about graphs, but does discuss queries on tree
relationships.
I've
Hi.
I am looking for a way to write a SELECT that finds connectivity
components of a graph or at least for one that given two nodes
determines if there is a path between them. It seems that this is not
possible, no matter what graph representation I choose. Which constructs
from set theory are
You mean, you want to be able to say something like:
select isConnected(a,b)
and get back a true/false, or maybe the path?
That seems quite doable in SQL, assuming you either store those results
and simply use sql to retrieve them, or use a stored proc to compute the
result each time.
On
I'm not sure if it's relevant to your question
http://www-2.cs.cmu.edu/~cache/pg_graph/
pg_graph provides a way of handling graph-based data structures within
the relational database PostgreSQL. In particular, it provides a convenient
means of inserting graphs as BLOB-like objects in the
A couple of links:
http://www.dbazine.com/ofinterest/oi-articles/celko24
http://www.dbmsmag.com/9603d06.html
On Jun 2, 2005, at 2:33 AM, Joachim Zobel wrote:
Hi.
I am looking for a way to write a SELECT that finds connectivity
components of a graph or at least for one that given two nodes
12 matches
Mail list logo
