Re: query that Bob is descendant of Alice
Date: Mon, 23 Apr 2001 22:56:44 GMT
"fervvac" <fervvac_at_ust.hk> wrote:
>+) In this way, A is a parent of B iff A's (start,end) covers B's
>(start,end). If we have B+-tree built for start and end attribute, I guess
>such query can be efficiently evaluated.
>+) If you have a DAG other than a tree, it seems still possible to apply the
>similar scheme, but there are some thing to consider what value is there in
Tricky. Numbering for DAGs can be done the same way. But, in DAG, numbers of children of particular node get fragmented. I can store largest fragment or all. For complex enough DAGs, intervals get very short and very numerous, which makes both alternatives useless.
/Robert Received on Tue Apr 24 2001 - 00:56:44 CEST