diff --git a/src/indexer.cc b/src/indexer.cc
index c2f86e95..c23ab8e2 100644
--- a/src/indexer.cc
+++ b/src/indexer.cc
@@ -620,7 +620,7 @@ void SetVarDetail(IndexVar* var,
       if (!is_enum_member)
         db->Resolve(var_type.value())->instances.push_back(var->id);
 
-      def.variable_type = *var_type;
+      def.type = *var_type;
     }
   }
 }
@@ -658,7 +658,7 @@ void OnIndexReference_Function(IndexFile* db,
 
 // static
 const int IndexFile::kMajorVersion = 12;
-const int IndexFile::kMinorVersion = 0;
+const int IndexFile::kMinorVersion = 1;
 
 IndexFile::IndexFile(const std::string& path, const std::string& contents)
     : id_cache(path), path(path), file_contents(contents) {}
@@ -1553,7 +1553,7 @@ void OnIndexDeclaration(CXClientData client_data, const CXIdxDeclInfo* decl) {
       // the function declaration is encountered since we won't receive ParmDecl
       // declarations for unnamed parameters.
       // TODO: See if we can remove this function call.
-      AddDeclTypeUsages(db, decl_cursor, var->def.variable_type,
+      AddDeclTypeUsages(db, decl_cursor, var->def.type,
                         decl->semanticContainer, decl->lexicalContainer);
 
       // We don't need to assign declaring type multiple times if this variable
@@ -1563,18 +1563,9 @@ void OnIndexDeclaration(CXClientData client_data, const CXIdxDeclInfo* decl) {
         switch (GetSymbolKind(decl->semanticContainer->cursor.kind)) {
           default:
             break;
-          case SymbolKind::Func: {
-            IndexFuncId parent_func_id =
-                db->ToFuncId(decl->semanticContainer->cursor);
-            var->def.parent_kind = SymbolKind::Func;
-            var->def.parent_id = Id<void>(parent_func_id);
-            break;
-          }
           case SymbolKind::Type: {
             IndexTypeId parent_type_id =
                 db->ToTypeId(decl->semanticContainer->cursor);
-            var->def.parent_kind = SymbolKind::Type;
-            var->def.parent_id = Id<void>(parent_type_id);
             db->Resolve(parent_type_id)->def.vars.push_back(var_id);
             break;
           }
diff --git a/src/indexer.h b/src/indexer.h
index 4d61cd86..6ed84d5b 100644
--- a/src/indexer.h
+++ b/src/indexer.h
@@ -89,6 +89,23 @@ using IndexVarId = Id<IndexVar>;
 
 struct IdCache;
 
+struct SymbolIdx {
+  Id<void> id;
+  SymbolKind kind;
+
+  bool operator==(const SymbolIdx& o) const {
+    return id == o.id && kind == o.kind;
+  }
+  bool operator!=(const SymbolIdx& o) const { return !(*this == o); }
+  bool operator<(const SymbolIdx& o) const {
+    if (id != o.id)
+      return id < o.id;
+    return kind < o.kind;
+  }
+};
+MAKE_REFLECT_STRUCT(SymbolIdx, kind, id);
+MAKE_HASHABLE(SymbolIdx, t.kind, t.id);
+
 struct Reference {
   Range range;
   Id<void> id;
@@ -96,6 +113,7 @@ struct Reference {
   Role role;
 
   bool HasValue() const { return range.HasValue(); }
+  operator SymbolIdx() const { return {id, kind}; }
   std::tuple<Range, Id<void>, SymbolKind, Role> ToTuple() const {
     return std::make_tuple(range, id, kind, role);
   }
@@ -107,34 +125,15 @@ struct Reference {
   }
 };
 
-struct SymbolIdx {
-  RawId idx;
-  SymbolKind kind;
-
-  bool operator==(const SymbolIdx& o) const {
-    return kind == o.kind && idx == o.idx;
-  }
-  bool operator!=(const SymbolIdx& o) const { return !(*this == o); }
-  bool operator<(const SymbolIdx& o) const {
-    if (kind != o.kind)
-      return kind < o.kind;
-    return idx < o.idx;
-  }
-};
-MAKE_REFLECT_STRUCT(SymbolIdx, kind, idx);
-MAKE_HASHABLE(SymbolIdx, t.kind, t.idx);
-
 // |id,kind| refer to the referenced entity.
 struct SymbolRef : Reference {
   SymbolRef() = default;
   SymbolRef(Range range, Id<void> id, SymbolKind kind, Role role)
     : Reference{range, id, kind, role} {}
   SymbolRef(Reference ref) : Reference(ref) {}
+  // FIXME Remove
   SymbolRef(SymbolIdx si)
-    : Reference{Range(), Id<void>(si.idx), si.kind, Role::None} {}
-
-  RawId Idx() const { return RawId(id); }
-  operator SymbolIdx() const { return SymbolIdx{Idx(), kind}; }
+    : Reference{Range(), si.id, si.kind, Role::None} {}
 };
 
 // Represents an occurrence of a variable/type, |id,kind| refer to the lexical
@@ -378,13 +377,11 @@ struct VarDefDefinitionData {
 
   typename F::FileId file;
   // Type of the variable.
-  Maybe<typename F::TypeId> variable_type;
+  Maybe<typename F::TypeId> type;
 
   // Function/type which declares this one.
-  Maybe<Id<void>> parent_id;
   int16_t short_name_offset = 0;
   int16_t short_name_size = 0;
-  SymbolKind parent_kind = SymbolKind::Invalid;
 
   ClangSymbolKind kind = ClangSymbolKind::Unknown;
   // Note a variable may have instances of both |None| and |Extern|
@@ -398,16 +395,12 @@ struct VarDefDefinitionData {
   bool is_macro() const { return kind == ClangSymbolKind::Macro; }
 
   bool operator==(const VarDefDefinitionData& o) const {
-    return detailed_name == o.detailed_name &&
-           spell == o.spell &&
-           extent == o.extent &&
-           variable_type == o.variable_type && parent_id == o.parent_id &&
-           parent_kind == o.parent_kind && kind == o.kind &&
-           storage == o.storage && hover == o.hover && comments == o.comments;
-  }
-  bool operator!=(const VarDefDefinitionData& other) const {
-    return !(*this == other);
+    return detailed_name == o.detailed_name && spell == o.spell &&
+           extent == o.extent && type == o.type &&
+           kind == o.kind && storage == o.storage && hover == o.hover &&
+           comments == o.comments;
   }
+  bool operator!=(const VarDefDefinitionData& o) const { return !(*this == o); }
 
   std::string_view ShortName() const {
     return std::string_view(detailed_name.c_str() + short_name_offset,
@@ -426,9 +419,7 @@ void Reflect(TVisitor& visitor, VarDefDefinitionData<Family>& value) {
   REFLECT_MEMBER(spell);
   REFLECT_MEMBER(extent);
   REFLECT_MEMBER(file);
-  REFLECT_MEMBER(variable_type);
-  REFLECT_MEMBER(parent_id);
-  REFLECT_MEMBER(parent_kind);
+  REFLECT_MEMBER(type);
   REFLECT_MEMBER(kind);
   REFLECT_MEMBER(storage);
   REFLECT_MEMBER_END();
diff --git a/src/message_handler.cc b/src/message_handler.cc
index 28baf160..27999882 100644
--- a/src/message_handler.cc
+++ b/src/message_handler.cc
@@ -151,7 +151,6 @@ void EmitSemanticHighlighting(QueryDatabase* db,
         QueryVar& var = db->GetVar(sym);
         if (!var.def)
           continue;  // applies to for loop
-        parent_kind = var.def->parent_kind;
         kind = var.def->kind;
         storage = var.def->storage;
         detailed_name = var.def->ShortName();
@@ -171,8 +170,7 @@ void EmitSemanticHighlighting(QueryDatabase* db,
 
     optional<lsRange> loc = GetLsRange(working_file, sym.range);
     if (loc) {
-      auto key = SymbolIdx{RawId(sym.id), sym.kind};
-      auto it = grouped_symbols.find(key);
+      auto it = grouped_symbols.find(sym);
       if (it != grouped_symbols.end()) {
         it->second.ranges.push_back(*loc);
       } else {
@@ -183,7 +181,7 @@ void EmitSemanticHighlighting(QueryDatabase* db,
         symbol.kind = kind;
         symbol.storage = storage;
         symbol.ranges.push_back(*loc);
-        grouped_symbols[key] = symbol;
+        grouped_symbols[sym] = symbol;
       }
     }
   }
diff --git a/src/messages/cquery_call_tree.cc b/src/messages/cquery_call_tree.cc
index 7f563773..fe09d742 100644
--- a/src/messages/cquery_call_tree.cc
+++ b/src/messages/cquery_call_tree.cc
@@ -169,7 +169,7 @@ struct CqueryCallTreeInitialHandler
          FindSymbolsAtLocation(working_file, file, request->params.position)) {
       if (sym.kind == SymbolKind::Func) {
         out.result =
-            BuildInitialCallTree(db, working_files, QueryFuncId(sym.Idx()));
+            BuildInitialCallTree(db, working_files, QueryFuncId(sym.id));
         break;
       }
     }
diff --git a/src/messages/cquery_member_hierarchy.cc b/src/messages/cquery_member_hierarchy.cc
index a072749c..34b0e5e7 100644
--- a/src/messages/cquery_member_hierarchy.cc
+++ b/src/messages/cquery_member_hierarchy.cc
@@ -15,7 +15,7 @@ struct Ipc_CqueryMemberHierarchyExpand
     : public RequestMessage<Ipc_CqueryMemberHierarchyExpand> {
   const static IpcId kIpcId = IpcId::CqueryMemberHierarchyExpand;
   struct Params {
-    size_t type_id;
+    QueryTypeId type_id;
   };
   Params params;
 };
@@ -27,8 +27,7 @@ struct Out_CqueryMemberHierarchy
     : public lsOutMessage<Out_CqueryMemberHierarchy> {
   struct Entry {
     std::string_view name;
-    // FIXME Usr
-    RawId type_id;
+    QueryTypeId type_id;
     lsLocation location;
   };
   lsRequestId id;
@@ -48,7 +47,7 @@ BuildInitial(QueryDatabase* db, WorkingFiles* working_files, QueryTypeId root) {
     return {};
 
   Out_CqueryMemberHierarchy::Entry entry;
-  entry.type_id = root.id;
+  entry.type_id = root;
   entry.name = root_type.def->ShortName();
   entry.location = *def_loc;
   return {entry};
@@ -64,9 +63,7 @@ ExpandNode(QueryDatabase* db, WorkingFiles* working_files, QueryTypeId root) {
   EachWithGen(db->vars, root_type.def->vars, [&](QueryVar& var) {
     Out_CqueryMemberHierarchy::Entry entry;
     entry.name = var.def->ShortName();
-    // FIXME WithGen
-    entry.type_id =
-        var.def->variable_type ? var.def->variable_type->id : RawId(-1);
+    entry.type_id = var.def->type ? *var.def->type : QueryTypeId();
     if (var.def->spell) {
       optional<lsLocation> loc =
           GetLsLocation(db, working_files, *var.def->spell);
@@ -95,13 +92,13 @@ struct CqueryMemberHierarchyInitialHandler
     for (const SymbolRef& sym :
          FindSymbolsAtLocation(working_file, file, request->params.position)) {
       if (sym.kind == SymbolKind::Type) {
-        out.result = BuildInitial(db, working_files, QueryTypeId(sym.Idx()));
+        out.result = BuildInitial(db, working_files, QueryTypeId(sym.id));
         break;
       }
       if (sym.kind == SymbolKind::Var) {
         QueryVar& var = db->GetVar(sym);
-        if (var.def && var.def->variable_type)
-          out.result = BuildInitial(db, working_files, *var.def->variable_type);
+        if (var.def && var.def->type)
+          out.result = BuildInitial(db, working_files, *var.def->type);
         break;
       }
     }
@@ -117,9 +114,8 @@ struct CqueryMemberHierarchyExpandHandler
     Out_CqueryMemberHierarchy out;
     out.id = request->id;
     // |ExpandNode| uses -1 to indicate invalid |type_id|.
-    if (request->params.type_id != size_t(-1))
-      out.result =
-          ExpandNode(db, working_files, QueryTypeId(request->params.type_id));
+    if (request->params.type_id.HasValue())
+      out.result = ExpandNode(db, working_files, request->params.type_id);
 
     QueueManager::WriteStdout(IpcId::CqueryMemberHierarchyExpand, out);
   }
diff --git a/src/messages/cquery_random.cc b/src/messages/cquery_random.cc
index 6b0febe0..bd8fb30c 100644
--- a/src/messages/cquery_random.cc
+++ b/src/messages/cquery_random.cc
@@ -33,7 +33,7 @@ void Add(const std::unordered_map<SymbolIdx, int>& sym2id,
          int n,
          double w = 1) {
   for (Id<Q> id : ids) {
-    auto it = sym2id.find(SymbolIdx{RawId(id), Kind<Q>::value});
+    auto it = sym2id.find(SymbolIdx{id, Kind<Q>::value});
     if (it != sym2id.end())
       adj[it->second][n] += w;
   }
@@ -47,24 +47,24 @@ struct CqueryRandomHandler : BaseMessageHandler<Ipc_CqueryRandom> {
 
     for (RawId i = 0; i < db->funcs.size(); i++)
       if (db->funcs[i].def) {
-        syms.push_back(SymbolIdx{i, SymbolKind::Func});
+        syms.push_back(SymbolIdx{Id<void>(i), SymbolKind::Func});
         sym2id[syms.back()] = n++;
       }
     for (RawId i = 0; i < db->types.size(); i++)
       if (db->types[i].def) {
-        syms.push_back(SymbolIdx{i, SymbolKind::Type});
+        syms.push_back(SymbolIdx{Id<void>(i), SymbolKind::Type});
         sym2id[syms.back()] = n++;
       }
     for (RawId i = 0; i < db->vars.size(); i++)
       if (db->vars[i].def) {
-        syms.push_back(SymbolIdx{i, SymbolKind::Var});
+        syms.push_back(SymbolIdx{Id<void>(i), SymbolKind::Var});
         sym2id[syms.back()] = n++;
       }
 
     std::vector<std::unordered_map<int, double>> adj(n);
     auto add = [&](const std::vector<Use>& uses, double w) {
       for (Use use : uses) {
-        auto it = sym2id.find(SymbolIdx{RawId(use.id), use.kind});
+        auto it = sym2id.find(use);
         if (it != sym2id.end())
           adj[it->second][n] += w;
       }
diff --git a/src/messages/cquery_vars.cc b/src/messages/cquery_vars.cc
index 3e0430e2..d36eca86 100644
--- a/src/messages/cquery_vars.cc
+++ b/src/messages/cquery_vars.cc
@@ -25,19 +25,19 @@ struct CqueryVarsHandler : BaseMessageHandler<Ipc_CqueryVars> {
     out.id = request->id;
     for (SymbolRef sym :
          FindSymbolsAtLocation(working_file, file, request->params.position)) {
-      RawId idx = sym.Idx();
+      Id<void> id = sym.id;
       switch (sym.kind) {
         default:
           break;
         case SymbolKind::Var: {
           QueryVar& var = db->GetVar(sym);
-          if (!var.def || !var.def->variable_type)
+          if (!var.def || !var.def->type)
             continue;
-          idx = var.def->variable_type->id;
+          id = *var.def->type;
         }
         // fallthrough
         case SymbolKind::Type: {
-          QueryType& type = db->types[idx];
+          QueryType& type = db->types[id.id];
           out.result =
               GetLsLocations(db, working_files, ToUses(db, type.instances));
           break;
diff --git a/src/messages/text_document_definition.cc b/src/messages/text_document_definition.cc
index d93a342b..048723b9 100644
--- a/src/messages/text_document_definition.cc
+++ b/src/messages/text_document_definition.cc
@@ -32,10 +32,9 @@ std::vector<Use> GetGotoDefinitionTargets(QueryDatabase* db,
       std::vector<Use> ret =
           GetDeclarationsOfSymbolForGotoDefinition(db, sym);
       QueryVar& var = db->GetVar(sym);
-      if (var.def && var.def->variable_type) {
+      if (var.def && var.def->type) {
         std::vector<Use> types = GetDeclarationsOfSymbolForGotoDefinition(
-            db, SymbolRef(Range(), Id<void>(var.def->variable_type->id),
-                          SymbolKind::Type, Role::None));
+            db, SymbolIdx{*var.def->type, SymbolKind::Type});
         ret.insert(ret.end(), types.begin(), types.end());
       }
       return ret;
diff --git a/src/messages/text_document_hover.cc b/src/messages/text_document_hover.cc
index 45c4a949..6d7b1961 100644
--- a/src/messages/text_document_hover.cc
+++ b/src/messages/text_document_hover.cc
@@ -9,7 +9,7 @@ std::pair<std::string_view, std::string_view> GetCommentsAndHover(
     SymbolRef sym) {
   switch (sym.kind) {
     case SymbolKind::Type: {
-      QueryType& type = db->types[sym.Idx()];
+      QueryType& type = db->GetType(sym);
       if (type.def)
         return {type.def->comments,
                 !type.def->hover.empty()
@@ -18,7 +18,7 @@ std::pair<std::string_view, std::string_view> GetCommentsAndHover(
       break;
     }
     case SymbolKind::Func: {
-      QueryFunc& func = db->funcs[sym.Idx()];
+      QueryFunc& func = db->GetFunc(sym);
       if (func.def)
         return {func.def->comments,
                 !func.def->hover.empty()
@@ -27,7 +27,7 @@ std::pair<std::string_view, std::string_view> GetCommentsAndHover(
       break;
     }
     case SymbolKind::Var: {
-      QueryVar& var = db->vars[sym.Idx()];
+      QueryVar& var = db->GetVar(sym);
       if (var.def)
         return {var.def->comments,
                 !var.def->hover.empty()
diff --git a/src/query.cc b/src/query.cc
index 28ea2878..09d176d1 100644
--- a/src/query.cc
+++ b/src/query.cc
@@ -95,25 +95,7 @@ optional<QueryVar::Def> ToQuery(const IdMap& id_map, const IndexVar::Def& var) {
   result.file = id_map.primary_file;
   result.spell = id_map.ToQuery(var.spell);
   result.extent = id_map.ToQuery(var.extent);
-  result.variable_type = id_map.ToQuery(var.variable_type);
-  if (result.parent_id)
-    switch (var.parent_kind) {
-      default:
-        break;
-      case SymbolKind::File:
-        result.parent_id = Id<void>(id_map.primary_file);
-        break;
-      case SymbolKind::Func:
-        result.parent_id = Id<void>(id_map.ToQuery(IndexFuncId(*var.parent_id)));
-        break;
-      case SymbolKind::Type:
-        result.parent_id = Id<void>(id_map.ToQuery(IndexTypeId(*var.parent_id)));
-        break;
-      case SymbolKind::Var:
-        result.parent_id = Id<void>(id_map.ToQuery(IndexVarId(*var.parent_id)));
-        break;
-    }
-  result.parent_kind = var.parent_kind;
+  result.type = id_map.ToQuery(var.type);
   result.kind = var.kind;
   result.storage = var.storage;
   return result;
@@ -871,8 +853,7 @@ void QueryDatabase::ImportOrUpdate(
     QueryFile& existing = files[it->second.id];
 
     existing.def = def.value;
-    UpdateSymbols(&existing.symbol_idx, SymbolKind::File,
-                        it->second.id);
+    UpdateSymbols(&existing.symbol_idx, SymbolKind::File, it->second);
   }
 }
 
@@ -893,8 +874,7 @@ void QueryDatabase::ImportOrUpdate(
     if (!(existing.def && existing.def->spell &&
           !def.value.spell)) {
       existing.def = std::move(def.value);
-      UpdateSymbols(&existing.symbol_idx, SymbolKind::Type,
-                    it->second.id);
+      UpdateSymbols(&existing.symbol_idx, SymbolKind::Type, it->second);
     }
   }
 }
@@ -916,8 +896,7 @@ void QueryDatabase::ImportOrUpdate(
     if (!(existing.def && existing.def->spell &&
           !def.value.spell)) {
       existing.def = std::move(def.value);
-      UpdateSymbols(&existing.symbol_idx, SymbolKind::Func,
-                    it->second.id);
+      UpdateSymbols(&existing.symbol_idx, SymbolKind::Func, it->second);
     }
   }
 }
@@ -939,15 +918,14 @@ void QueryDatabase::ImportOrUpdate(std::vector<QueryVar::DefUpdate>&& updates) {
           !def.value.spell)) {
       existing.def = std::move(def.value);
       if (!def.value.is_local())
-        UpdateSymbols(&existing.symbol_idx, SymbolKind::Var,
-                      it->second.id);
+        UpdateSymbols(&existing.symbol_idx, SymbolKind::Var, it->second);
     }
   }
 }
 
 void QueryDatabase::UpdateSymbols(Maybe<Id<void>>* symbol_idx,
                                   SymbolKind kind,
-                                  RawId idx) {
+                                  Id<void> idx) {
   if (!symbol_idx->has_value()) {
     *symbol_idx = Id<void>(symbols.size());
     symbols.push_back(SymbolIdx{idx, kind});
@@ -955,7 +933,7 @@ void QueryDatabase::UpdateSymbols(Maybe<Id<void>>* symbol_idx,
 }
 
 std::string_view QueryDatabase::GetSymbolDetailedName(RawId symbol_idx) const {
-  RawId idx = symbols[symbol_idx].idx;
+  RawId idx = symbols[symbol_idx].id.id;
   switch (symbols[symbol_idx].kind) {
     default:
       break;
@@ -980,7 +958,7 @@ std::string_view QueryDatabase::GetSymbolDetailedName(RawId symbol_idx) const {
 }
 
 std::string_view QueryDatabase::GetSymbolShortName(RawId symbol_idx) const {
-  RawId idx = symbols[symbol_idx].idx;
+  RawId idx = symbols[symbol_idx].id.id;
   switch (symbols[symbol_idx].kind) {
     default:
       break;
diff --git a/src/query.h b/src/query.h
index 7eb60022..0bd1619c 100644
--- a/src/query.h
+++ b/src/query.h
@@ -280,7 +280,7 @@ struct QueryDatabase {
   void ImportOrUpdate(std::vector<QueryType::DefUpdate>&& updates);
   void ImportOrUpdate(std::vector<QueryFunc::DefUpdate>&& updates);
   void ImportOrUpdate(std::vector<QueryVar::DefUpdate>&& updates);
-  void UpdateSymbols(Maybe<Id<void>>* symbol_idx, SymbolKind kind, RawId idx);
+  void UpdateSymbols(Maybe<Id<void>>* symbol_idx, SymbolKind kind, Id<void> idx);
   std::string_view GetSymbolDetailedName(RawId symbol_idx) const;
   std::string_view GetSymbolShortName(RawId symbol_idx) const;
 
@@ -290,7 +290,7 @@ struct QueryDatabase {
   Maybe<QueryFuncId> GetQueryFuncIdFromUsr(Usr usr);
   Maybe<QueryVarId> GetQueryVarIdFromUsr(Usr usr);
 
-  QueryFileId GetFileId(Reference ref) {
+  QueryFileId GetFileId(SymbolIdx ref) {
     switch (ref.kind) {
       case SymbolKind::Invalid:
         break;
@@ -317,16 +317,16 @@ struct QueryDatabase {
     }
     return QueryFileId();
   }
-  QueryFile& GetFile(Reference ref) {
+  QueryFile& GetFile(SymbolIdx ref) {
     return files[ref.id.id];
   }
-  QueryFunc& GetFunc(Reference ref) {
+  QueryFunc& GetFunc(SymbolIdx ref) {
     return funcs[ref.id.id];
   }
-  QueryType& GetType(Reference ref) {
+  QueryType& GetType(SymbolIdx ref) {
     return types[ref.id.id];
   }
-  QueryVar& GetVar(Reference ref) {
+  QueryVar& GetVar(SymbolIdx ref) {
     return vars[ref.id.id];
   }
 };
diff --git a/src/query_utils.cc b/src/query_utils.cc
index c169f612..d40b79a9 100644
--- a/src/query_utils.cc
+++ b/src/query_utils.cc
@@ -27,7 +27,7 @@ Maybe<Use> GetDefinitionSpellingOfSymbol(QueryDatabase* db,
 }
 
 Maybe<Use> GetDefinitionSpellingOfSymbol(QueryDatabase* db,
-                                         SymbolRef sym) {
+                                         SymbolIdx sym) {
   switch (sym.kind) {
     case SymbolKind::Type: {
       QueryType& type = db->GetType(sym);
@@ -56,7 +56,7 @@ Maybe<Use> GetDefinitionSpellingOfSymbol(QueryDatabase* db,
   return nullopt;
 }
 
-Maybe<Use> GetDefinitionExtentOfSymbol(QueryDatabase* db, SymbolRef sym) {
+Maybe<Use> GetDefinitionExtentOfSymbol(QueryDatabase* db, SymbolIdx sym) {
   switch (sym.kind) {
     case SymbolKind::Type: {
       QueryType& type = db->GetType(sym);
@@ -77,7 +77,8 @@ Maybe<Use> GetDefinitionExtentOfSymbol(QueryDatabase* db, SymbolRef sym) {
       break;
     }
     case SymbolKind::File:
-      return Use(Reference(sym));
+      return Use(Range(Position(0, 0), Position(0, 0)), sym.id, sym.kind,
+                 Role::None);
     case SymbolKind::Invalid: {
       assert(false && "unexpected");
       break;
@@ -87,7 +88,7 @@ Maybe<Use> GetDefinitionExtentOfSymbol(QueryDatabase* db, SymbolRef sym) {
 }
 
 Maybe<QueryFileId> GetDeclarationFileForSymbol(QueryDatabase* db,
-                                               SymbolRef sym) {
+                                               SymbolIdx sym) {
   switch (sym.kind) {
     case SymbolKind::Type: {
       QueryType& type = db->GetType(sym);
@@ -110,7 +111,7 @@ Maybe<QueryFileId> GetDeclarationFileForSymbol(QueryDatabase* db,
       break;
     }
     case SymbolKind::File:
-      return QueryFileId(sym.Idx());
+      return QueryFileId(sym.id);
     case SymbolKind::Invalid: {
       assert(false && "unexpected");
       break;
@@ -159,29 +160,28 @@ std::vector<Use> ToUses(QueryDatabase* db, const std::vector<QueryVarId>& ids) {
 }
 
 std::vector<Use> GetUsesOfSymbol(QueryDatabase* db,
-                                 SymbolRef sym,
+                                 SymbolIdx sym,
                                  bool include_decl) {
   switch (sym.kind) {
     case SymbolKind::Type: {
-      QueryType& type = db->types[sym.Idx()];
+      QueryType& type = db->GetType(sym);
       std::vector<Use> ret = type.uses;
       if (include_decl && type.def && type.def->spell)
         ret.push_back(*type.def->spell);
       return ret;
     }
     case SymbolKind::Func: {
-      // TODO: the vector allocation could be avoided.
-      QueryFunc& func = db->funcs[sym.Idx()];
+      QueryFunc& func = db->GetFunc(sym);
       std::vector<Use> ret = func.uses;
       if (include_decl) {
-        AddRange(&ret, func.declarations);
         if (func.def && func.def->spell)
           ret.push_back(*func.def->spell);
+        AddRange(&ret, func.declarations);
       }
       return ret;
     }
     case SymbolKind::Var: {
-      QueryVar& var = db->vars[sym.Idx()];
+      QueryVar& var = db->GetVar(sym);
       std::vector<Use> ret = var.uses;
       if (include_decl) {
         if (var.def && var.def->spell)
@@ -200,7 +200,7 @@ std::vector<Use> GetUsesOfSymbol(QueryDatabase* db,
 
 std::vector<Use> GetDeclarationsOfSymbolForGotoDefinition(
     QueryDatabase* db,
-    SymbolRef sym) {
+    SymbolIdx sym) {
   switch (sym.kind) {
     case SymbolKind::Type: {
       // Returning the definition spelling of a type is a hack (and is why the
@@ -447,11 +447,11 @@ std::vector<lsLocation> GetLsLocations(
 // Returns a symbol. The symbol will have *NOT* have a location assigned.
 optional<lsSymbolInformation> GetSymbolInfo(QueryDatabase* db,
                                             WorkingFiles* working_files,
-                                            SymbolRef sym,
+                                            SymbolIdx sym,
                                             bool use_short_name) {
   switch (sym.kind) {
     case SymbolKind::File: {
-      QueryFile& file = db->files[sym.Idx()];
+      QueryFile& file = db->GetFile(sym);
       if (!file.def)
         break;
 
@@ -568,7 +568,7 @@ std::vector<SymbolRef> FindSymbolsAtLocation(WorkingFile* working_file,
               int t = static_cast<int>(a.kind) - static_cast<int>(b.kind);
               if (t)
                 return t > 0;
-              return a.Idx() < b.Idx();
+              return a.id < b.id;
             });
 
   return symbols;
diff --git a/src/query_utils.h b/src/query_utils.h
index dc85ffea..8d5f43be 100644
--- a/src/query_utils.h
+++ b/src/query_utils.h
@@ -10,10 +10,10 @@
 Maybe<Use> GetDefinitionSpellingOfSymbol(QueryDatabase* db,
                                          QueryFuncId id);
 Maybe<Use> GetDefinitionSpellingOfSymbol(QueryDatabase* db,
-                                         SymbolRef sym);
-Maybe<Use> GetDefinitionExtentOfSymbol(QueryDatabase* db, SymbolRef sym);
+                                         SymbolIdx sym);
+Maybe<Use> GetDefinitionExtentOfSymbol(QueryDatabase* db, SymbolIdx sym);
 Maybe<QueryFileId> GetDeclarationFileForSymbol(QueryDatabase* db,
-                                               SymbolRef sym);
+                                               SymbolIdx sym);
 
 std::vector<Use> ToUses(QueryDatabase* db,
                         const std::vector<QueryFuncId>& ids);
@@ -23,11 +23,11 @@ std::vector<Use> ToUses(QueryDatabase* db,
                         const std::vector<QueryVarId>& ids);
 
 std::vector<Use> GetUsesOfSymbol(QueryDatabase* db,
-                                 SymbolRef sym,
+                                 SymbolIdx sym,
                                  bool include_decl);
 std::vector<Use> GetDeclarationsOfSymbolForGotoDefinition(
     QueryDatabase* db,
-    SymbolRef sym);
+    SymbolIdx sym);
 
 bool HasCallersOnSelfOrBaseOrDerived(QueryDatabase* db, QueryFunc& root);
 std::vector<Use> GetCallersForAllBaseFunctions(QueryDatabase* db,
@@ -55,7 +55,7 @@ std::vector<lsLocation> GetLsLocations(QueryDatabase* db,
 // Returns a symbol. The symbol will have *NOT* have a location assigned.
 optional<lsSymbolInformation> GetSymbolInfo(QueryDatabase* db,
                                             WorkingFiles* working_files,
-                                            SymbolRef sym,
+                                            SymbolIdx sym,
                                             bool use_short_name);
 
 std::vector<SymbolRef> FindSymbolsAtLocation(WorkingFile* working_file,
diff --git a/src/serializer.cc b/src/serializer.cc
index b17f2a0d..c52bfdf8 100644
--- a/src/serializer.cc
+++ b/src/serializer.cc
@@ -252,10 +252,8 @@ void Reflect(TVisitor& visitor, IndexVar& value) {
   REFLECT_MEMBER2("declarations", value.declarations);
   REFLECT_MEMBER2("spell", value.def.spell);
   REFLECT_MEMBER2("extent", value.def.extent);
-  REFLECT_MEMBER2("variable_type", value.def.variable_type);
+  REFLECT_MEMBER2("type", value.def.type);
   REFLECT_MEMBER2("uses", value.uses);
-  REFLECT_MEMBER2("parent_id", value.def.parent_id);
-  REFLECT_MEMBER2("parent_kind", value.def.parent_kind);
   REFLECT_MEMBER2("kind", value.def.kind);
   REFLECT_MEMBER2("storage", value.def.storage);
   REFLECT_MEMBER_END();