CREATE TEMPORARY TABLE t1 (i1 INT, t1 TEXT) using memoryam;
INSERT INTO t1 VALUES (1, 'missy');
INSERT INTO t1 VALUES (2, 'kitten');
INSERT INTO t1 VALUES (NULL, NULL);
SELECT * FROM t1;
 i1 |   t1   
----+--------
  1 | missy
  2 | kitten
    | 
(3 rows)

DROP TABLE t1;
CREATE TEMPORARY TABLE t1 (f REAL, d DOUBLE PRECISION) using memoryam;
INSERT INTO t1 VALUES (1.1, 2.4);
INSERT INTO t1 VALUES (2.3, 23.6);
SELECT * FROM t1;
  f  |  d   
-----+------
 1.1 |  2.4
 2.3 | 23.6
(2 rows)

DROP TABLE t1;