I have seen some applications using proprietary databases crash or experience data corruption if the application was running when the OS (Windows in this case) performs a disk defragmentation. My question is this: Does SQLite (sqlite3) suffer from this issue? In other words, would it ever be dealing with the disk on a block level, or just on a file level?
SQLite uses only the OS's file access functions, so as long as the defrag tool works with concurrent file accesses, you should be fine.