Boolean type - Amazon Redshift

Boolean type

Use the BOOLEAN data type to store true and false values in a single-byte column. The following table describes the three possible states for a Boolean value and the literal values that result in that state. Regardless of the input string, a Boolean column stores and outputs "t" for true and "f" for false.

State Valid literal values Storage
True TRUE 't' 'true' 'y' 'yes' '1' 1 byte
False FALSE 'f' 'false' 'n' 'no' '0' 1 byte
Unknown NULL 1 byte

You can use an IS comparison to check a Boolean value only as a predicate in the WHERE clause. You can't use the IS comparison with a Boolean value in the SELECT list.


You could use a BOOLEAN column to store an "Active/Inactive" state for each customer in a CUSTOMER table.

create table customer( custid int, active_flag boolean default true);
insert into customer values(100, default);
select * from customer; custid | active_flag -------+-------------- 100 | t

If no default value (true or false) is specified in the CREATE TABLE statement, inserting a default value means inserting a null.

In this example, the query selects users from the USERS table who like sports but do not like theatre:

select firstname, lastname, likesports, liketheatre from users where likesports is true and liketheatre is false order by userid limit 10; firstname | lastname | likesports | liketheatre ----------+------------+------------+------------- Lars | Ratliff | t | f Mufutau | Watkins | t | f Scarlett | Mayer | t | f Shafira | Glenn | t | f Winifred | Cherry | t | f Chase | Lamb | t | f Liberty | Ellison | t | f Aladdin | Haney | t | f Tashya | Michael | t | f Lucian | Montgomery | t | f (10 rows)

The following example selects users from the USERS table for whom is it unknown whether they like rock music.

select firstname, lastname, likerock from users where likerock is unknown order by userid limit 10; firstname | lastname | likerock ----------+----------+---------- Rafael | Taylor | Vladimir | Humphrey | Barry | Roy | Tamekah | Juarez | Mufutau | Watkins | Naida | Calderon | Anika | Huff | Bruce | Beck | Mallory | Farrell | Scarlett | Mayer | (10 rows)

The following example returns an error because it uses an IS comparison in the SELECT list.

select firstname, lastname, likerock is true as "check" from users order by userid limit 10; [Amazon](500310) Invalid operation: Not implemented

The following example succeeds because it uses an equal comparison ( = ) in the SELECT list instead of the IS comparison.

select firstname, lastname, likerock = true as "check" from users order by userid limit 10; firstname | lastname | check ----------+-----------+------ Rafael | Taylor | Vladimir | Humphrey | Lars | Ratliff | true Barry | Roy | Reagan | Hodge | true Victor | Hernandez | true Tamekah | Juarez | Colton | Roy | false Mufutau | Watkins | Naida | Calderon |