Update DESIGN.md

DOC/DESIGN.md

@@ -13,7 +13,7 @@ The diagram below shows a high-level view of a rqlite node.
 
 ## File system
 ### Raft
-The Raft layer always creates a file -- it creates the _Raft log_. The log stores the set of committed SQLite commands, in the order which they were executed. This log is authoritative record of every change that has happened to the system. It may also contain some read-only queries as entries, depending on read-consistency choices.
+The Raft layer always creates a file -- it creates the _Raft log_. This log stores the set of committed SQLite commands, in the order which they were executed. This log is authoritative record of every change that has happened to the system. It may also contain some read-only queries as entries, depending on read-consistency choices. Since every node in an rqlite cluster applies the entries log in exactly the same way, this guarantees that the SQLite database is the same on every node.
 
 ### SQLite
 By default, the SQLite layer doesn't create a file. Instead, it creates the database in memory. rqlite can create the SQLite database on disk, if so configured at start-time, by passing `-on-disk` to `rqlited` at startup. Regardless of whether rqlite creates a database entirely in memory, or on disk, the SQLite database is completely recreated everytime `rqlited` starts, using the information stored in the Raft log.