Tuple type

The tuple data type holds fixed-length sets of typed positional fields. Use a tuple as an alternative to a user-defined type. A tuple can accommodate many fields (32768), more than can be prudently used. Typically, create a tuple with a few fields.

In the table creation statement, use angle brackets and a comma delimiter to declare the tuple component types. Surround tuple values in parentheses to insert the values into a table, as shown below:

CREATE TABLE collect_things (
  k int PRIMARY KEY,
  v tuple<int, text, float>
);

INSERT INTO collect_things (k, v) VALUES(0, (3, 'bar', 2.1));

SELECT * FROM collect_things;

 k | v
---+-----------------
 0 | (3, 'bar', 2.1)

frozen <tuple <int, tuple<text, double>>>

You can filter a selection using a tuple.

CREATE INDEX on collect_things (v);

SELECT * FROM collect_things WHERE v = (3, 'bar', 2.1);

 k | v
---+-----------------
 0 | (3, 'bar', 2.1)

You can nest tuples as shown in the following example:

CREATE TABLE nested (k int PRIMARY KEY, t tuple <int, tuple<text, double>>);

INSERT INTO nested (k, t) VALUES (0, (3, ('foo', 3.4)));