Fix missing of default database (#710)

Signed-off-by: JaySon-Huang <[email protected]>

For TiFlash deployed with TiDB cluster, we use "system" as the default database, which always exists in TiFlash.

dbms/src/Server/Server.cpp

@@ -343,8 +343,8 @@ int Server::main(const std::vector<std::string> & /*args*/)
     const std::string path = all_normal_path[0];
     TiFlashRaftConfig raft_config(path, config(), log);
     // Use pd address to define which default_database we use by defauly.
-    // For mock test, we use "default". For deployed with pd/tidb/tikv use "db_1" , whose name is "test" in TiDB.
-    std::string default_database = config().getString("default_database", raft_config.pd_addrs.empty() ? "default" : "db_1");
+    // For mock test, we use "default". For deployed with pd/tidb/tikv use "system", which is always exist in TiFlash.
+    std::string default_database = config().getString("default_database", raft_config.pd_addrs.empty() ? "default" : "system");
     global_context->setPath(path);
     global_context->initializePartPathSelector(std::move(all_normal_path), std::move(all_fast_path));