> That depends on what you mean by "reader without write permissions". UNIX permission > A LOGICAL (ie, application level) read-only connection is still required to have PHYSICAL (ie, Operating System level) write-access to the SHM file. YOU are prevented from writing to the database files, however SQLITE itself has no such limitation. This contradicts [this message](https://sqlite.org/forum/forumpost/3713bf6332) by D. Richard Hipp: > Yes. Read locks can be taken on files to which you do not have write permission. What am I supposed to conclude? Look, I'm really looking for the answer for a simple question: is WAL suitable when some readers don't have write permission? It's a very simple, and very important question. So far, my answer is NO, the WAL mode is not suitable when some readers don't have write permission, because a WAL database can exist without any -shm and -wal file, making them unusable by such readers. **I think this should be explicitly stated in the "disadvantages" section of https://www.sqlite.org/wal.html.**