Re: Cluster table based on grand parent?

On 3/28/23 06:17, Dominique Devienne wrote:
> Hi again,

>
> Thanks for any insights. --DD
>
> PS: At this point, I don't even know how much cluster affects performance.
>     But because it can affect the schema structure (by denormalizing),
> i'd rather know early.

You will need to explain to me how it denormalizes? It reorders rows by
index definition and does not maintain that order over updates and inserts.

>
> [1]: https://www.postgresql.org/docs/current/sql-cluster.html
> <https://www.postgresql.org/docs/current/sql-cluster.html>
>
> ```
> dd=> create table parent (id int generated always as identity primary
> key, name text not null unique);
> CREATE TABLE
>
> dd=> create table child (id int generated always as identity primary
> key, parent int not null references parent(id) on delete cascade, name
> text not null, unique(parent, name));
> CREATE TABLE
>
> dd=> create table grandchild (id int generated always as identity
> primary key, parent int not null references child(id) on delete cascade,
> name text not null, unique(parent, name));
> CREATE TABLE
> ```

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com