Re: logical column ordering

Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:

> Over the time I've heard various use cases for this patch, but in most
> cases it was quite speculative. If you have an idea where this might be
> useful, can you explain it here, or maybe point me to a place where it's
> described?

One use case is to be able to suppress default display of columns that are
used for internal purposes. For example, incremental maintenance of
materialized views will require storing a "count(t)" column, and sometimes
state information for aggregate columns, in addition to what the users
explicitly request. At the developers' meeting there was discussion of
whether and how to avoid displaying these by default, and it was felt that
when we have this logical column ordering it would be good to have a way to
suppress default display. Perhaps this could be as simple as a special
value for logical position.
--

Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company