is_nullable column of information_schema.columns table

On Sat, Dec 28, 2019 at 08:19:51PM +0000, PG Doc comments form wrote:

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/12/infoschema-columns.html
Description:

is_nullable column of information_schema.columns table does not show correct
values for columns of views. For tables that column shows correct values
whether a column is nullable or not. I think the documentation should
include this information although better solution is to correct that error.

Can you show us an example query with the output? Thanks. Also, which
Postgres version?

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +

On Sat, 2019-12-28 at 20:19 +0000, PG Doc comments form wrote:

Page: https://www.postgresql.org/docs/12/infoschema-columns.html
Description:

is_nullable column of information_schema.columns table does not show correct
values for columns of views. For tables that column shows correct values
whether a column is nullable or not. I think the documentation should
include this information although better solution is to correct that error.

All columns of a view are defined as nullable, whether they can assume
that value or not. PostgreSQL does not attempt to deduce the nullability
of columns from the view definition.

So the information in information_schema.columns is correct.
Remember that nullability does not imply that there are actually NULL values.

Yours,
Laurenz Albe
--
Cybertec | https://www.cybertec-postgresql.com