Tomas Vondra wrote: > On 26.2.2015 23:42, Kevin Grittner wrote: > > 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 tosuppress default > > display. Perhaps this could be as simple as a special value for > > logical position. > > I don't see how hiding columns is related to this patch at all. That's > completely unrelated thing, and it certainly is not part of this patch.
It's not directly related to the patch, but I think the intent is that once we have this patch it will be possible to apply other transformations, such as having columns that are effectively hidden -- consider for example the idea that attlognum be set to a negative number. (For instance, consider the idea that system columns may all have -1 as attlognum, which would just be an indicator that they are never present in logical column expansion. That makes sense to me; what reason do we have to keep them using the current attnums they have?) -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
