[sroussey]

On commercial databases from Oracle and Microsoft, you can cluster the DB on any index. Really would love for Postresql to do the same.

[cwbriscoe]

You can but new rows will not be clustered until you re-cluster.

CLUSTER table_name USING index_name;

[sroussey]

I remember that for MySQL MyISAM (syntax was different) in the olden days. I thought Oracle let you do it though. My bad.

MySQL Innodb and other have real clustered primary key indexes with all the pluses and minuses that entails.