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.klaver@aklaver.com