Re: Table Design for Hierarchical Data

On 04/07/10 11:00, Achilleas Mantzios wrote:

> Column | Type | Modifiers
> ---------+-----------+---------------------------------------------------------------------------
> id | integer | not null default nextval(('public.paintgentypes_id_seq'::text)::regclass)
> name | text | not null
> parents | integer[] |

> The parents of any node to the root, i.e. the path of any node to the root are depicted as
> parents[0] : immediate parent
> parents[1] : immediate parent of the above parent
> .....
> parents[n] : root of the tree

what this schema gives?

(1) the parent branch in one select.
what else?
nothing.

compare it to a nested-tree

id | integer | NOT NULL
name | text | not null
parent | integer |
l | numeric
r | numeric

(1) parent branch in one select
(2) child subtree in one select
(it makes a sence!)