postgres/contrib/pg_tde/documentation/docs/how-to/decrypt.md

Remove Encryption from an Encrypted Table

Method 1. Change the access method

If you encrypted a table with the tde_heap access method and need to remove the encryption from it, run the following command against the desired table (mytable in the example below):

ALTER TABLE mytable SET ACCESS METHOD heap;

Note that the SET ACCESS METHOD command drops hint bits and this may affect performance. Running a plain SELECT count(*) or VACUUM command on the entire table will check every tuple for visibility and set its hint bits. Therefore, after executing the ALTER TABLE command, run a simple count(*) on your tables:

SELECT count(*) FROM mytable;

Check that the table is not encrypted:

SELECT pg_tde_is_encrypted('mytable');

The output returns f meaning that the table is no longer encrypted.

Method 2. Create a new not encrypted table on the base of the encrypted one

Alternatively, you can create a new not encrypted table with the same structure and data as the initial table. For example, the original encrypted table is EncryptedCustomers. Use the following command to create a new table Customers:

CREATE TABLE Customers AS SELECT * FROM EncryptedCustomers;

The new table Customers inherits the structure and the data from EncryptedCustomers.

(Optional) If you no longer need the EncryptedCustomers table, you can delete it.

DROP TABLE EncryptedCustomers;