http://localhost:1313/tags/regex/Recent content in Regex on LorbicHugoenMon, 30 Mar 2026 23:45:00 +0530http://localhost:1313/clickhouse-regex-data-masking/Tue, 31 Mar 2026 22:30:00 +0530http://localhost:1313/clickhouse-regex-data-masking/<p>If you&rsquo;re running a production observability stack, you&rsquo;ve already leaked PII. An engineer forgot to redact an email in a log line, or a JWT token ended up in a stack trace.</p> <p>In most databases, the only fix is to <code>DELETE</code> the data—killing your metrics along with the sensitive info. But ClickHouse has a more elegant approach: <strong>Data Masking Policies</strong>.</p> <p>By defining a policy at the role level, you can use regex to swap sensitive patterns with <code>[REDACTED]</code> in real-time, before the query results even leave the server.</p>