How to Ensure GDPR Compliance in PostgreSQL

How can I make my PostgreSQL database GDPR compliant?

Techniques and settings that make a PostgreSQL database handle EU personal data in a GDPR-compliant way.

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Description

What does GDPR compliance mean for a PostgreSQL database?

GDPR requires you to protect EU residents’ personal data, limit access, document processing, and erase data on request.PostgreSQL offers built-in features—encryption, row-level security, auditing—that map directly to these obligations.

How do I discover personal data columns quickly?

Query the catalog:
SELECT table_schema, table_name, column_name FROM information_schema.columns WHERE column_name ILIKE '%email%' OR column_name ILIKE '%name%' OR column_name ILIKE '%phone%'; Tag findings with the comment command to keep an audit trail.

How do I encrypt personal data at rest?

Using pgcrypto for column-level encryption

Create a symmetric key in a secure vault and reference it in SQL:

CREATE EXTENSION IF NOT EXISTS pgcrypto; ALTER TABLE customers ADD COLUMN email_enc bytea; UPDATE customers SET email_enc = pgp_sym_encrypt(email, current_setting('app.symkey')); ALTER TABLE customers DROP COLUMN email;

Store the key outside the database and pass it through SET app.symkey per session.

How do I secure access with row-level security (RLS)?

Enable RLS on sensitive tables:

ALTER TABLE customers ENABLE ROW LEVEL SECURITY; CREATE POLICY customer_is_owner ON customers USING (id = current_setting('app.current_customer_id')::int);

Now each session sees only its own row, satisfying GDPR’s data-minimization principle.

How do I implement data retention and right-to-erasure?

Create a scheduled job (pg_cron or external scheduler) that anonymizes or deletes expired data:

DELETE FROM orders WHERE customer_id IN (SELECT id FROM customers WHERE deleted_at IS NOT NULL) AND order_date < NOW() - INTERVAL '7 years';

For soft deletes, replace identifying columns with hashes using digest().

Full GDPR workflow example

1.Tag personal columns
2. Encrypt with pgcrypto
3. Activate RLS policies
4. Audit access via pgaudit
5. Schedule retention jobs. The next section shows the code end-to-end.

Best practices checklist

• Always separate keys from data.
• Document policies in the COMMENT catalog.
• Test RLS with SET ROLE.
• Log every SELECT on personal tables via pgaudit.log = 'read'.

Why How to Ensure GDPR Compliance in PostgreSQL is important

How to Ensure GDPR Compliance in PostgreSQL Example Usage


-- Mask customer email for marketing exports while staying GDPR-compliant
SELECT id,
       pgp_sym_decrypt(email_enc, current_setting('app.symkey')) AS email,
       created_at
FROM customers
WHERE created_at > NOW() - INTERVAL '30 days'
  AND consent_marketing = TRUE;

How to Ensure GDPR Compliance in PostgreSQL Syntax


-- Identify personal data columns
SELECT table_schema, table_name, column_name
FROM information_schema.columns
WHERE table_name IN ('customers','orders','orderitems')
  AND column_name IN ('name','email');

-- Column-level encryption example
CREATE EXTENSION IF NOT EXISTS pgcrypto;
SET app.symkey = 'env:SYMKEY_32_BYTES';
UPDATE customers
SET email_enc = pgp_sym_encrypt(email, current_setting('app.symkey'));
ALTER TABLE customers DROP COLUMN email;

-- Row-Level Security
ALTER TABLE orders ENABLE ROW LEVEL SECURITY;
CREATE POLICY customer_orders ON orders
USING (customer_id = current_setting('app.current_customer_id')::int);

-- Right to erasure
DELETE FROM customers WHERE id = 42;  -- cascade deletes/anonymize with FK rules

Common Mistakes

Ignoring catalog metadata: Developers often encrypt data but forget to update column comments. Without documentation, audits fail. Always use COMMENT ON COLUMN to label personal data.
Testing without RLS: Teams enable row-level security but keep superuser roles during QA, masking policy gaps. Test with low-privilege roles to verify isolation.