Hi,
the tip in the "Adding a column" section is not true anymore since PostgreSQL
11:
https://www.postgresql.org/docs/current/ddl-alter.html#DDL-ALTER-ADDING-A-COLUMN
Attached a patch proposal for this.
Regards
Daniel
diff --git a/doc/src/sgml/ddl.sgml b/doc/src/sgml/ddl.sgml
index 9301f0227d..62058ec3b1 100644
--- a/doc/src/sgml/ddl.sgml
+++ b/doc/src/sgml/ddl.sgml
@@ -1318,12 +1318,7 @@ ALTER TABLE products ADD COLUMN description text CHECK (description <> '')
<tip>
<para>
Adding a column with a default requires updating each row of the
- table (to store the new column value). However, if no default is
- specified, <productname>PostgreSQL</productname> is able to avoid
- the physical update. So if you intend to fill the column with
- mostly nondefault values, it's best to add the column with no default,
- insert the correct values using <command>UPDATE</command>, and then add any
- desired default as described below.
+ table (to store the new column value) if the default is volatile.
</para>
</tip>
</sect2>
