Re: Error "is not a table or materialized view" when creating a unique index on a materialized view on PostgreSQL 9.5.10

I also tested these commands on a PostgreSQL 12.1 and the error is the
same.

------ Original Message ------
From: "Sterpu Victor" <victor(at)caido(dot)ro>
To: pgsql-admin(at)postgresql(dot)org
Sent: 2020-02-06 11:03:28 AM
Subject: Error "is not a table or materialized view" when creating a
unique index on a materialized view on PostgreSQL 9.5.10

>Hello
>
>I have PostgreSQL 9.5.10 and when I receive the error: <table> is not a
>table or materialized view when I try to create a unique index on a
>materialized view.
>
>These are the SQL commands:
>CREATE MATERIALIZED VIEW public.focg_uni AS
>SELECT f.nrfo,
> to_char(min(fd.validfrom), 'YYYY'::text) AS anul_internarii
> FROM focg f
> JOIN focgdepartment fd ON fd.idfocg = f.id
> GROUP BY f.nrfo
>WITH DATA;
>
>REFRESH MATERIALIZED VIEW public.focg_uni
>
>CREATE UNIQUE INDEX focg_uni_check_index ON focg_uni_check(nrfo, an);
>
>ERROR: "focg_uni_check" is not a table or materialized view
>********** Error **********
>
>ERROR: "focg_uni_check" is not a table or materialized view
>SQL state: 42809
>
>
>Thank you