What I would like to do is put the specific case for handling 3 common 'alter column' changes when that column is referenced in a view.
create table base_table ( id bigserial, acol varchar(10), bcol int, ccol varchar(1000));
create or replace view base_view as select id, acol, bcol, ccol from base_table;
create or replace view dep_view as select id, length(acol), bcol, ccol from base_view;
I would like to review the 3 specific cases:
alter table base_table alter column acol type varchar(20); -- was varchar(10)
alter table base_table alter column bcol type bigint; -- was int
alter table base_table alter column ccol type text; -- was varchar(1000)
At the moment these 3 statements all require that the views be dropped first and then re-created last. The first case looks like:
-- for the varchar(10) to varchar(20) change
drop view dep_view;
drop view base_view;
alter table base_table ALTER COLUMN bcol type varchar(20);
create or replace view base_view as select id, acol, bcol from base_table;
create or replace view dep_view as select id, length(acol) from base_view;
In practical terms this need to drop and re-create the views gets harder/bigger with more view dependencies. With large complex schema's this becomes a rather large pain.
Having read all the previous discussions on the general topic of altering tables with dependent views I realise this is a complex and difficult issue in general but I'd like to see if there was some support for looking at these 3 more specific changes.
1. making a varchar column larger e.g. varchar(10) -> varchar(20)
2. changing int to bigint
3. changing varchar to text
I have seen that there are people motivated enough to update pg_attribute directly (update pg_attribute a set a.atttypmod = 20 + 4 ...).
What are the thoughts on support these 3 specific cases?
Thanks, Rob.