This is fascinating. I've got two basic questions, however:<p>1) Is this always going to be performant with indices? It seems like "time" is kind of like another index here, and when designing queries which indices are used and in which order can be the difference between taking milliseconds and taking an hour. It's not obvious to me whether this will have hidden gotchas or query execution complexities, or if it's designed in a way that's so restricted and integrated into indices themselves that query performance will always remain within the same order of magnitude<p>2) What is the advantage of building this into the database, instead of adding your own timestamp columns e.g. 'created_timestamp' and 'expunged_timestamp'? Not only does that seem relatively simple, but it gives you the flexibility of creating indices across multiple columns (including them) for desired performance, the ability to work with tools like mysqldump, and it's just conceptually simpler to understand the database. And if the question is data security, is there a real difference between a "security layer" that is built around the database, versus one built into it? It would be fairly simple to write a command-line tool to change the MariaDB data files directly, no?