Column Masking Example
This example implements partial masking of data in a view. Such masking is often used for displaying credit card numbers. A privileged user creates the view, which unprivileged users (that is, without the UNMASK privilege) can then safely use because the credit card number is partially masked.
CREATE TABLE masking_table (int_masked INTEGER8 MASKED NOT NULL);
INSERT INTO masking_table VALUES
(4556288950166430),
(4929591048738619),
(4929933452574454),
(4929571480910157),
(4557432740524776);
Issued by a privileged user:
CREATE VIEW masking_view AS
SELECT DISTINCT CONCAT (
MASK_COLUMN (SUBSTR (varchar (int_masked), 1, 4) AS BASIC), ' ',
MASK_COLUMN (SUBSTR (varchar (int_masked), 5, 4) AS BASIC), ' ',
MASK_COLUMN (SUBSTR (varchar (int_masked), 9, 4) AS BASIC), ' ',
MASK_COLUMN (SUBSTR (varchar (int_masked), 13, 4) AS UNMASK)
) AS "partial cc"
FROM masking_table;
SELECT * FROM masking_view ORDER BY 1;
+-------------------+
|partial cc |
+-------------------+
|4556 2889 5016 6430|
|4557 4327 4052 4776|
|4929 5714 8091 0157|
|4929 5910 4873 8619|
|4929 9334 5257 4454|
+-------------------+
Issued by an unprivileged user:
SELECT * FROM masking_view ORDER BY 1;
+-------------------+
|partial cc |
+-------------------+
|**** **** **** 0157|
|**** **** **** 4454|
|**** **** **** 4776|
|**** **** **** 6430|
|**** **** **** 8619|
+-------------------+