CREATE TABLE copy1 (a int, b float);
-- COPY TO/FROM not authorized from client.
DO LANGUAGE plpgsql $$
BEGIN
  COPY copy1 TO stdout;
END;
$$;
ERROR:  cannot COPY to/from client in PL/pgSQL
CONTEXT:  PL/pgSQL function inline_code_block line 3 at SQL statement
DO LANGUAGE plpgsql $$
BEGIN
  COPY copy1 FROM stdin;
END;
$$;
ERROR:  cannot COPY to/from client in PL/pgSQL
CONTEXT:  PL/pgSQL function inline_code_block line 3 at SQL statement
DO LANGUAGE plpgsql $$
BEGIN
  EXECUTE 'COPY copy1 TO stdout';
END;
$$;
ERROR:  cannot COPY to/from client in PL/pgSQL
CONTEXT:  PL/pgSQL function inline_code_block line 3 at EXECUTE
DO LANGUAGE plpgsql $$
BEGIN
  EXECUTE 'COPY copy1 FROM stdin';
END;
$$;
ERROR:  cannot COPY to/from client in PL/pgSQL
CONTEXT:  PL/pgSQL function inline_code_block line 3 at EXECUTE
-- Valid cases
-- COPY FROM
DO LANGUAGE plpgsql $$
BEGIN
  COPY copy1 FROM '@abs_srcdir@/data/copy1.data';
END;
$$;
SELECT * FROM copy1 ORDER BY 1;
 a |  b  
---+-----
 1 | 1.1
 2 | 2.2
 3 | 3.3
(3 rows)

TRUNCATE copy1;
DO LANGUAGE plpgsql $$
BEGIN
  EXECUTE 'COPY copy1 FROM ''@abs_srcdir@/data/copy1.data''';
END;
$$;
SELECT * FROM copy1 ORDER BY 1;
 a |  b  
---+-----
 1 | 1.1
 2 | 2.2
 3 | 3.3
(3 rows)

-- COPY TO
-- Copy the data externally once, then process it back to the table.
DO LANGUAGE plpgsql $$
BEGIN
  COPY copy1 TO '@abs_builddir@/results/copy1.data';
END;
$$;
TRUNCATE copy1;
DO LANGUAGE plpgsql $$
BEGIN
  COPY copy1 FROM '@abs_builddir@/results/copy1.data';
END;
$$;
DO LANGUAGE plpgsql $$
BEGIN
  EXECUTE 'COPY copy1 FROM ''@abs_builddir@/results/copy1.data''';
END;
$$;
SELECT * FROM copy1 ORDER BY 1;
 a |  b  
---+-----
 1 | 1.1
 1 | 1.1
 2 | 2.2
 2 | 2.2
 3 | 3.3
 3 | 3.3
(6 rows)

DROP TABLE copy1;