1 Status of vertical clustered index - 2 Join using (fk_constraint) suggestion - 3 Status of pgsql's parser autonomization

Hello,

1. I was told that M$ SQLServer provides huge performance deltas over
PostgreSQL when dealing with index-unaligned queries :
create index i on t (a,b, c);
select * from t where b=... and c=...;
Columnar storage has been tried by various companies, CitusData,
EnterpriseDB, 2ndQuadrant, Fujitsu Enterprise Postgres. It has been
discussed quite a lot, last thread that I was able to find being in
2017,
https://www.postgresql.org/message-id/CAJrrPGfaC7WC9NK6PTTy6YN-NN%2BhCy8xOLAh2doYhVg5d6HsAA%40mail.gmail.com
where Fujitsu's patch made it quite far.
What is the status on such a storage manager extension interface ?

2. What do you think of adding a new syntax : 'from t join t2 using
(fk_constraint)' ? And further graph algorithms to make automatic joins ?
Both 'natural join' and 'using (column_name)' are useless when the
columns are not the same in source and destination.
Plus it is often the case that the fk_constraints are over numerous
columns, even though this is usually advised against. But when this case
happens there will be a significant writing speedup.
I have been bothered by this to the point that I developed a
graphical-query-builder plugin for pgModeler,
https://github.com/maxzor/plugins/tree/master/graphicalquerybuilder#automatic-join-mode
,
but I believe such a syntax would be much better in the core!

3. What is the status of making the internal parser of PostgreSQL less
coupled to the core, and easier to cherry-pick from outside?
It would be great to incorporate it into companion projects : pgAdmin4,
pgModeler, pgFormatter...

BR, Maxime Chambonnet