Why Mask Email Addresses in SQL*Plus Logs

The email addresses sat there in the SQL*Plus log. Raw. Unmasked. Waiting for anyone with access to read them.

Plaintext emails in logs are a security leak. They expose sensitive data to anyone who can open the file. This is an easy problem to fix in SQL*Plus, and it should be fixed before those logs leave your machine.

Why Mask Email Addresses in SQL*Plus Logs

Logs often get shipped, archived, or viewed across teams. Without masking, every address is visible in full. This breaks privacy requirements and can violate compliance rules like GDPR. Even in non-production environments, it’s bad practice to keep them exposed.

How to Mask Email Addresses in SQL*Plus

You don’t have to rewrite your entire logging setup. Use functions in SQL to replace part of the email with a placeholder before it’s printed. In SQL*Plus, a simple query can redact the username portion while leaving the domain visible for troubleshooting.

Example:

SELECT REGEXP_REPLACE(email, '([[:alnum:]_.%-]+)@', '***@') AS masked_email
FROM users;

This replaces everything before the @ with three asterisks. Adjust the regex for your company’s standards. You can run this inside SQL*Plus and capture the output into your spool file, ensuring that stored logs never hold the original email.

If you are storing logs via SPOOL, run the masking query instead of direct selects. Keep masking on the database side, not after-the-fact, so nothing sensitive leaves your system unprotected.

Best Practices

• Always test your regex to ensure no edge cases slip through.
• Mask consistently across all tables and queries that print emails.
• Automate masking in scripts so no one has to remember to apply it.

Security in logging is about control. Masking email addresses in SQL*Plus is simple, fast, and reduces exposure risk to near zero. The less sensitive data you store, the less you have to defend.

See secure logging, masking, and compliance-ready pipelines live in minutes at hoop.dev.