Mask Email ID in PostgreSQL

Masking email IDs in PostgreSQL involves replacing part of the email address with asterisks (*) or other characters while preserving the format. Here's a general approach to mask email IDs in PostgreSQL:

1. Identify the Email ID Column: Determine which column in your table stores email addresses.

2. Define the Masking Logic: Decide on the masking logic, such as whether to mask the username, domain, or both, and how many characters to mask.

3. Use SQL Functions to Apply Masking: Use SQL functions such as `SUBSTRING`, `POSITION`, and `CONCAT` to apply the masking logic to the email IDs.

Here's an example of how you can mask email IDs by replacing part of the username and domain with asterisks:

SELECT 

    CASE 

        WHEN POSITION('@' IN email_id) > 0 THEN

            CONCAT(

                LEFT(email_id, POSITION('@' IN email_id) - 2),

                REPEAT('*', POSITION('@' IN email_id) - 2),

                SUBSTRING(email_id FROM POSITION('@' IN email_id))

            )

        ELSE 

            email_id 

    END AS masked_email_id

FROM 

    your_table;

In this example, `your_table` is the name of your table, and `email_id` is the column containing the email addresses. This query will replace part of the username and domain with asterisks while preserving the domain's top-level domain (TLD). Adjust the logic as needed based on your specific requirements.

Here are few FAQs:-

1. Can I mask email IDs directly in the database without altering the original data?

   - Answer: Yes, you can use SQL queries to mask email IDs by creating a new column or selecting masked values without altering the original data.

2. What is the recommended approach for masking email IDs while preserving their format?

   - Answer: It's common to replace part of the email ID with asterisks (*) while retaining the original format. This maintains data usability while protecting sensitive information.

3. How can I adjust the masking logic to meet specific requirements, such as masking only certain characters or domains?

   - Answer: You can customize the masking logic using SQL functions like `SUBSTRING`, `POSITION`, and `CONCAT` to target specific parts of the email ID for masking while preserving others.

4. Are there any performance considerations when masking large volumes of email IDs in PostgreSQL?

   - Answer: Depending on the size of your dataset, applying masking logic within SQL queries may impact performance. It's essential to test the performance and optimize queries if necessary.

5. Can I automate the masking process to ensure consistent application across multiple datasets or tables?

   - Answer: Yes, you can automate the masking process using stored procedures, scripts, or ETL (Extract, Transform, Load) processes to apply consistent masking logic across various datasets or tables.