Re: A new approach to storing ordered hierarchical data in RDBs.
From: paul c <toledobythesea_at_oohay.ac>
Date: Wed, 22 Nov 2006 00:40:11 GMT
Message-ID: <L%M8h.345570$5R2.18790_at_pd7urf3no>
>
> I especially laughed at the phrase "XML handles hierarchical ... quite
> well". How the dickens does XML per se calculate transitive closure or
> depth from an adjency list or an adjaceny list from a tree? It seems to
> me that XML by itself only allows adhoc solutions that are just as
> non-declarative as various SQL versions. For that matter, the original
> relational model seems to requires similar adhoc additions. I don't
> have a solution, but it seems to me that all three are lacking and it is
> irresponsible, ignorant and cavalier to use the adverb "well" regarding
> accomplishing closure with any of them.
>
> p
Date: Wed, 22 Nov 2006 00:40:11 GMT
Message-ID: <L%M8h.345570$5R2.18790_at_pd7urf3no>
paul c wrote:
> Lennart wrote:
>
>> Aloha Kakuikanu wrote: >> [...] >> >>> Please make sure you use terms correctly. What you have meant by >>> "lineage" is "transitive closure". This article >>> http://www.sqlteam.com/item.asp?ItemID=8866 >>> uses the term "lineage" in the sense of "materialized path". >> >> >> >> I especially liked the phrase "Don't worry about the loop" :-) >> >> /Lennart >>
>
> I especially laughed at the phrase "XML handles hierarchical ... quite
> well". How the dickens does XML per se calculate transitive closure or
> depth from an adjency list or an adjaceny list from a tree? It seems to
> me that XML by itself only allows adhoc solutions that are just as
> non-declarative as various SQL versions. For that matter, the original
> relational model seems to requires similar adhoc additions. I don't
> have a solution, but it seems to me that all three are lacking and it is
> irresponsible, ignorant and cavalier to use the adverb "well" regarding
> accomplishing closure with any of them.
>
> p
sorry about the spelling, mine is going down-hill as fast as my opinions are ossifying, i guess it should be adjacency but sooner or later some marketing type will spell it 'agency list'.
p Received on Wed Nov 22 2006 - 01:40:11 CET