BEGIN;
CREATE EXTENSION IF NOT EXISTS anon CASCADE;
CREATE TABLE disease (
  id SERIAL,
  name TEXT,
  treatment TEXT
);
SELECT anon.k_anonymity('disease');
WARNING:  There is no identifier declared for relation 'disease'.
HINT:  Use SECURITY LABEL FOR anon ... to declare which columns are indirect identifiers.
 k_anonymity 
-------------
            
(1 row)

CREATE TABLE patient (
  ssn SERIAL,
  firstname TEXT,
  zipcode INTEGER,
  birth DATE,
  disease TEXT
);
COPY patient
FROM STDIN CSV QUOTE AS '"' DELIMITER ' ';
SELECT * FROM patient;
 ssn | firstname | zipcode |   birth    |    disease    
-----+-----------+---------+------------+---------------
   1 | Alice     |   47678 | 12-29-1979 | Heart Disease
   2 | Bob       |   47678 | 03-22-1979 | Heart Disease
   3 | Caroline  |   47678 | 07-22-1988 | Heart Disease
   4 | David     |   47905 | 03-04-1997 | Flu
   5 | Eleanor   |   47909 | 12-15-1989 | Heart Disease
   6 | Frank     |   47906 | 07-04-1998 | Cancer
   7 | Geri      |   47605 | 10-30-1987 | Heart Disease
   8 | Harry     |   47673 | 06-13-1978 | Cancer
   9 | Ingrid    |   47607 | 12-12-1991 | Cancer
(9 rows)

SECURITY LABEL FOR anon ON COLUMN patient.firstname IS 'INDIRECT IDENTIFIER';
SECURITY LABEL FOR anon ON COLUMN patient.zipcode IS 'INDIRECT IDENTIFIER';
SECURITY LABEL FOR anon ON COLUMN patient.birth IS 'INDIRECT IDENTIFIER';
SELECT anon.k_anonymity('patient') = min(kanonymity)
FROM (
  SELECT COUNT(*) as kanonymity
  FROM patient
  GROUP BY firstname, zipcode, birth
) AS k
;
 ?column? 
----------
 t
(1 row)

CREATE TEMPORARY TABLE anon_patient
AS SELECT
  'REDACTED'::TEXT AS firstname,
  anon.generalize_int4range(zipcode,1000) AS zipcode,
  anon.generalize_daterange(birth,'decade') AS birth,
  disease
FROM patient
;
SECURITY LABEL FOR anon ON COLUMN anon_patient.firstname IS 'INDIRECT IDENTIFIER';
SECURITY LABEL FOR anon ON COLUMN anon_patient.zipcode IS 'INDIRECT IDENTIFIER';
SECURITY LABEL FOR anon ON COLUMN anon_patient.birth IS 'INDIRECT IDENTIFIER';
SELECT * FROM anon_patient;
 firstname |    zipcode    |          birth          |    disease    
-----------+---------------+-------------------------+---------------
 REDACTED  | [47000,48000) | [01-01-1970,01-01-1980) | Heart Disease
 REDACTED  | [47000,48000) | [01-01-1970,01-01-1980) | Heart Disease
 REDACTED  | [47000,48000) | [01-01-1980,01-01-1990) | Heart Disease
 REDACTED  | [47000,48000) | [01-01-1990,01-01-2000) | Flu
 REDACTED  | [47000,48000) | [01-01-1980,01-01-1990) | Heart Disease
 REDACTED  | [47000,48000) | [01-01-1990,01-01-2000) | Cancer
 REDACTED  | [47000,48000) | [01-01-1980,01-01-1990) | Heart Disease
 REDACTED  | [47000,48000) | [01-01-1970,01-01-1980) | Cancer
 REDACTED  | [47000,48000) | [01-01-1990,01-01-2000) | Cancer
(9 rows)

SELECT anon.k_anonymity('anon_patient') = min(c)
FROM (
  SELECT COUNT(*) as c
  FROM anon_patient
  GROUP BY firstname, zipcode, birth
) AS k
;
 ?column? 
----------
 t
(1 row)

ROLLBACK;