út 1. 2. 2022 v 4:38 odesílatel Julien Rouhaud <rjuju123@gmail.com> napsal:
Hi,
On Mon, Jan 31, 2022 at 10:05:44PM +0100, Pavel Stehule wrote: > > I don't feel good about forcing an alias. relname doesn't ensure > uniqueness. You can have two views with the same name from different > schemas. Moreover this field is necessary only when a deparsed query is > printed, not always.
Yes I agree.
> Isn't possible to compute the correct subquery alias in print time when it > is missing?
Actually I think that the current code already does everything to generate unique refnames, it's just that they don't get printed for a query after view expansions. I modified the patch to simply make sure that an alias is displayed when it's a subquery and the output using a custom pg_get_query_def is like that:
# select pg_get_query_def('select * from nsp1.v1'); pg_get_query_def ------------------------------- SELECT nb + FROM ( SELECT 1 AS nb) v1;+
(1 row)
# select pg_get_query_def('select * from nsp1.v1, nsp2.v1'); pg_get_query_def ------------------------------- SELECT v1.nb, + v1_1.nb + FROM ( SELECT 1 AS nb) v1,+ ( SELECT 1 AS nb) v1_1; +
(1 row)
I tested your patch, and it looks so it is working without any problem. All tests passed.
There is just one question. If printalias = true will be active for all cases or just with some flag?
I didn't find any visible change of this modification without your function, so maybe it can be active for all cases without any condition.
