request to support "conflict on(col1 or col2) do update xxx" feature

[sai <pianoboysai@xxxxxxxxx>]

I think this feature is a very common requirement.

For example. I created  a table,  which username and email columns are unique separately

CREATE TABLE test (
    username    VARCHAR(255) NOT NULL UNIQUE,
    email       VARCHAR(255) NOT NULL UNIQUE,
    status      VARCHAR(127)
);
I want to do an "update" when any of these two columns triggers conflict.

But postgres doesn't  support "conflict(col1 or col2)",  it only supports "conflict(col1)", like this:

insert into test (username, email, status) values('u1','e1','s1') on conflict(username) do  update set status=CURRENT_TIMESTAMP;

Many guys said you can create a unique index on a combination of two columns like "unique(username, email)",  this is an absolutely incorrect answer ! 

Assume I insert two records:
1. u1, e1, s1
2. u2, e2 ,s2
Now when I insert (u1, e3, s3),  the combination (u1, e3) is unique,  but if you use "on conflict(username, email) do update xxx", you will still get an exception  !  it can not process conflict on any one of the columns !

So I think we should have a simple syntax to support it? (I don't want to write a Stored Procedure or use any Complex/hacker solution, thanks.).

Can the postgres team implement this feature?

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Best Regards,

Jin