Discussion: https://www.postgresql.org/message-id/flat/
20170618071607.GA16418%40nol.local
This clause is useful for example when copying values between tables.
Writing INSERT INTO tbl2 OVERRIDING USER VALUE SELECT * FROM
tbl1 will copy from tbl1 all columns that
- are not identity columns in tbl2 but will continue
- the sequence counters for any identity columns.
+ are not identity columns in tbl2 while values for
+ the identity columns in tbl2 will be generated by
+ the sequences associated with tbl2.