Standalone mode uses temp DB files by default (RIPD-1129):

* If a [database_path] is configured, it will always be used, and tables
  will be upgraded on startup.

src/ripple/app/ledger/OrderBookDB.cpp

@@ -70,7 +70,7 @@ void OrderBookDB::setup(
     {
         // nothing to do
     }
-    else if (app_.config().RUN_STANDALONE)
+    else if (app_.config().standalone())
         update(ledger);
     else
         app_.getJobQueue().addJob(