Re: Self referencing composite datatype - Mailing list pgsql-general

From Alban Hertroys
Subject Re: Self referencing composite datatype
Date
Msg-id 0EFEC07D-92C9-482F-8A8D-65545ADEBA4A@gmail.com
Whole thread Raw
In response to Re: Self referencing composite datatype  (Sergey Konoplev <gray.ru@gmail.com>)
Responses Re: Self referencing composite datatype  (Sergey Konoplev <gray.ru@gmail.com>)
Re: Self referencing composite datatype  (Chris Travers <chris.travers@gmail.com>)
List pgsql-general
On Aug 8, 2013, at 4:11, Sergey Konoplev <gray.ru@gmail.com> wrote:

> create table node as (
>  id integer primary key,
>  r integer, s integer,
>  children integer[] element references node
> );
>
> so you could download 9.3rc2 and experimant with it.
>
> Now (on <=9.2.x) you can create the table without FK
>
> create table node as (
>  id integer primary key,
>  r integer, s integer,
>  children integer[]
> );
>
> and check integrity by triggers.


Or, instead of attempting to reference all child nodes from the parent, reference the parent node from each child node.
That's been supported in PG versions like forever and can be queried fairly efficiently using recursive CTE's since PG
9.

Alban Hertroys
--
If you can't see the forest for the trees,
cut the trees and you'll find there is no forest.



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