DROP AGGREGATE IF EXISTS array_accum(anyelement);

CREATE OR REPLACE FUNCTION array_unique (ANYARRAY)
RETURNS ANYARRAY
LANGUAGE SQL
AS '
SELECT ARRAY(
    SELECT DISTINCT $1[s.i] AS "foo"
    FROM
        generate_series(array_lower($1,1), array_upper($1,1)) AS s(i)
);
';

CREATE AGGREGATE array_accum (anyelement)
(
    sfunc = array_append,
    stype = anyarray,
    initcond = '{}',
    finalfunc = array_unique
);

create table radar (SampleID integer,SubmitterID integer);
insert into radar values( 1 , 1 );
insert into radar values( 1 , 2 );
insert into radar values( 1 , 3 );
insert into radar values( 2 , 1 );
insert into radar values( 2 , 2 );
insert into radar values( 3 , 1 );
insert into radar values( 3 , 2 );
CONSTRAINT fk_radar_ref_samples FOREIGN KEY ("SampleID")
      REFERENCES samples ("SampleID")
CONSTRAINT fk_radar_ref_users FOREIGN KEY ("SubmitterID")
      REFERENCES users ("UserID")

create table samples (SampleID integer, AnalystID integer);
insert into samples values( 1 , 1 );
insert into samples values( 2 , 2 );
insert into samples values( 3 , 3 );
CONSTRAINT "PK_samples" PRIMARY KEY ("SampleID")
CONSTRAINT fk_samples_ref_analysts FOREIGN KEY ("AnalystID")
      REFERENCES analysts ("UserID")

create table users (UserID integer, UserName text);
insert into users values( 1 ,"Вася");
insert into users values( 2 ,"Петя");
insert into users values( 3 ,"Саша");
CONSTRAINT "PK_users" PRIMARY KEY ("UserID")

SampleID    Submitters                 Analyst
 1                Вася, Петя, Саша      Вася
 2                Вася, Петя               Петя
 3                Вася, Петя               Саша