(Josh from RethinkDB here) The sibling comment by ubercore has the right link. And your concern is important, since without security, why not just expose your

(Josh from RethinkDB here) The sibling comment by ubercore has the right link. And your concern is important, since without security, why not just expose your db to the frontend directly? At a high level, the permission system: 1. Is a whitelist approach (you can't do anything by default) 2. Allows you to specify query shapes that are allowed to be run by the current user. This prevents queries of the wrong shape from ever hitting the database, helping with scalability. 3. Has a fallback to full javascript rules which can depend on the data on disk. A little slower than the query rules, but allows much more flexibility where you need it. And you can combine them with a query rule to do a rough first pass of what is acceptable. Ultimately, the permissions system is designed to prevent unfettered database access, but it also has an eye towards performance in the case of DOS attacks. Horizon overall attempts to use only indexed queries, low resource usage operations etc, so you don't accidentally invite DOS attacks . Now, I'm not claiming we're DOS proof or anything, but I just intend to mention we have an eye towards it when we talk about security.