diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index c65446df4a..728046b0d4 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -7,8 +7,10 @@ use ra_arena::{impl_arena_id, Arena, RawId};
 use ra_syntax::ast::{self, NameOwner, StructKind, TypeAscriptionOwner};
 
 use crate::{
-    type_ref::TypeRef, AsName, AstDatabase, Crate, DefDatabase, Enum, EnumVariant, FieldSource,
-    HasSource, HirDatabase, Name, Source, Struct, StructField, Union,
+    db::{AstDatabase, DefDatabase, HirDatabase},
+    type_ref::TypeRef,
+    AsName, Crate, Enum, EnumVariant, FieldSource, HasSource, Name, Source, Struct, StructField,
+    Union,
 };
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 1bb2f9f284..2bac6122bd 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -8,6 +8,7 @@ use ra_syntax::ast::{self, NameOwner, TypeAscriptionOwner};
 
 use crate::{
     adt::{EnumVariantId, StructFieldId, VariantDef},
+    db::{AstDatabase, DefDatabase, HirDatabase},
     diagnostics::DiagnosticSink,
     expr::{validation::ExprValidator, Body, BodySourceMap},
     generics::HasGenericParams,
@@ -29,7 +30,7 @@ use crate::{
     },
     type_ref::Mutability,
     type_ref::TypeRef,
-    AsName, AstDatabase, AstId, DefDatabase, Either, HasSource, HirDatabase, Name, Ty,
+    AsName, AstId, Either, HasSource, Name, Ty,
 };
 
 /// hir::Crate describes a single crate. It's the main interface with which
diff --git a/crates/ra_hir/src/code_model/docs.rs b/crates/ra_hir/src/code_model/docs.rs
index a2b4d8e975..99edc58140 100644
--- a/crates/ra_hir/src/code_model/docs.rs
+++ b/crates/ra_hir/src/code_model/docs.rs
@@ -3,8 +3,9 @@ use std::sync::Arc;
 use ra_syntax::ast;
 
 use crate::{
-    AstDatabase, Const, DefDatabase, Enum, EnumVariant, FieldSource, Function, HasSource,
-    HirDatabase, MacroDef, Module, Static, Struct, StructField, Trait, TypeAlias, Union,
+    db::{AstDatabase, DefDatabase, HirDatabase},
+    Const, Enum, EnumVariant, FieldSource, Function, HasSource, MacroDef, Module, Static, Struct,
+    StructField, Trait, TypeAlias, Union,
 };
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
diff --git a/crates/ra_hir/src/code_model/src.rs b/crates/ra_hir/src/code_model/src.rs
index b9ffb0c7a8..c0cb27b477 100644
--- a/crates/ra_hir/src/code_model/src.rs
+++ b/crates/ra_hir/src/code_model/src.rs
@@ -4,9 +4,10 @@ use ra_syntax::{
 };
 
 use crate::{
-    ids::AstItemDef, AstDatabase, Const, DefDatabase, Either, Enum, EnumVariant, FieldSource,
-    Function, HasBody, HirDatabase, HirFileId, MacroDef, Module, ModuleSource, Static, Struct,
-    StructField, Trait, TypeAlias, Union,
+    db::{AstDatabase, DefDatabase, HirDatabase},
+    ids::AstItemDef,
+    Const, Either, Enum, EnumVariant, FieldSource, Function, HasBody, HirFileId, MacroDef, Module,
+    ModuleSource, Static, Struct, StructField, Trait, TypeAlias, Union,
 };
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
diff --git a/crates/ra_hir/src/diagnostics.rs b/crates/ra_hir/src/diagnostics.rs
index 475dd5766e..60da336954 100644
--- a/crates/ra_hir/src/diagnostics.rs
+++ b/crates/ra_hir/src/diagnostics.rs
@@ -3,7 +3,7 @@ use std::{any::Any, fmt};
 use ra_syntax::{ast, AstNode, AstPtr, SyntaxNode, SyntaxNodePtr, TextRange};
 use relative_path::RelativePathBuf;
 
-use crate::{HirDatabase, HirFileId, Name, Source};
+use crate::{db::HirDatabase, HirFileId, Name, Source};
 
 /// Diagnostic defines hir API for errors and warnings.
 ///
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index fc21e269f4..698fa671b5 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -9,10 +9,11 @@ use ra_syntax::{ast, AstPtr};
 use rustc_hash::FxHashMap;
 
 use crate::{
+    db::HirDatabase,
     path::GenericArgs,
     ty::primitive::{UncertainFloatTy, UncertainIntTy},
     type_ref::{Mutability, TypeRef},
-    DefWithBody, Either, HasSource, HirDatabase, Name, Path, Resolver, Source,
+    DefWithBody, Either, HasSource, Name, Path, Resolver, Source,
 };
 
 pub use self::scope::ExprScopes;
diff --git a/crates/ra_hir/src/expr/lower.rs b/crates/ra_hir/src/expr/lower.rs
index 6afd80989d..8bd041ff08 100644
--- a/crates/ra_hir/src/expr/lower.rs
+++ b/crates/ra_hir/src/expr/lower.rs
@@ -9,12 +9,13 @@ use ra_syntax::{
 use test_utils::tested_by;
 
 use crate::{
+    db::HirDatabase,
     name::{AsName, Name, SELF_PARAM},
     path::GenericArgs,
     ty::primitive::{FloatTy, IntTy, UncertainFloatTy, UncertainIntTy},
     type_ref::TypeRef,
-    DefWithBody, Either, HirDatabase, HirFileId, MacroCallLoc, MacroFileKind, Mutability, Path,
-    Resolver, Source,
+    DefWithBody, Either, HirFileId, MacroCallLoc, MacroFileKind, Mutability, Path, Resolver,
+    Source,
 };
 
 use super::{
diff --git a/crates/ra_hir/src/expr/scope.rs b/crates/ra_hir/src/expr/scope.rs
index b6d7f3fc14..de0983a7ed 100644
--- a/crates/ra_hir/src/expr/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -4,8 +4,9 @@ use ra_arena::{impl_arena_id, Arena, RawId};
 use rustc_hash::FxHashMap;
 
 use crate::{
+    db::HirDatabase,
     expr::{Body, Expr, ExprId, Pat, PatId, Statement},
-    DefWithBody, HirDatabase, Name,
+    DefWithBody, Name,
 };
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
diff --git a/crates/ra_hir/src/expr/validation.rs b/crates/ra_hir/src/expr/validation.rs
index 1202913e2f..6a22e13189 100644
--- a/crates/ra_hir/src/expr/validation.rs
+++ b/crates/ra_hir/src/expr/validation.rs
@@ -5,12 +5,13 @@ use rustc_hash::FxHashSet;
 
 use crate::{
     adt::AdtDef,
+    db::HirDatabase,
     diagnostics::{DiagnosticSink, MissingFields, MissingOkInTailExpr},
     expr::AstPtr,
     name,
     path::{PathKind, PathSegment},
     ty::{ApplicationTy, InferenceResult, Ty, TypeCtor},
-    Function, HirDatabase, ModuleDef, Name, Path, PerNs, Resolution,
+    Function, ModuleDef, Name, Path, PerNs, Resolution,
 };
 
 use super::{Expr, ExprId, RecordLitField};
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index ec756f2c36..e0d0d4209a 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -8,7 +8,10 @@ use ra_db::{salsa, FileId};
 use ra_prof::profile;
 use ra_syntax::{ast, AstNode, Parse, SyntaxNode};
 
-use crate::{AstDatabase, AstId, DefDatabase, FileAstId, InternDatabase, Module, Source};
+use crate::{
+    db::{AstDatabase, DefDatabase, InternDatabase},
+    AstId, FileAstId, Module, Source,
+};
 
 /// hir makes heavy use of ids: integer (u32) handlers to various things. You
 /// can think of id as a pointer (but without a lifetime) or a file descriptor
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index 62a41719a4..162ab02b14 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -9,13 +9,13 @@ use ra_syntax::{
 
 use crate::{
     code_model::{Module, ModuleSource},
+    db::{AstDatabase, DefDatabase, HirDatabase},
     generics::HasGenericParams,
     ids::LocationCtx,
     resolve::Resolver,
     ty::Ty,
     type_ref::TypeRef,
-    AstDatabase, Const, DefDatabase, Function, HasSource, HirDatabase, HirFileId, Source, TraitRef,
-    TypeAlias,
+    Const, Function, HasSource, HirFileId, Source, TraitRef, TypeAlias,
 };
 
 #[derive(Debug, Default, PartialEq, Eq)]
diff --git a/crates/ra_hir/src/lang_item.rs b/crates/ra_hir/src/lang_item.rs
index fd6609fb8a..832fdf1f57 100644
--- a/crates/ra_hir/src/lang_item.rs
+++ b/crates/ra_hir/src/lang_item.rs
@@ -4,8 +4,8 @@ use std::sync::Arc;
 use ra_syntax::{ast::AttrsOwner, SmolStr};
 
 use crate::{
-    AstDatabase, Crate, DefDatabase, Enum, Function, HasSource, HirDatabase, ImplBlock, Module,
-    ModuleDef, Static, Struct, Trait,
+    db::{AstDatabase, DefDatabase, HirDatabase},
+    Crate, Enum, Function, HasSource, ImplBlock, Module, ModuleDef, Static, Struct, Trait,
 };
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index c3e5899216..7c2a68992c 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -49,7 +49,6 @@ mod code_model;
 mod marks;
 
 use crate::{
-    db::{AstDatabase, DefDatabase, HirDatabase, InternDatabase},
     ids::MacroFileKind,
     name::AsName,
     resolve::Resolver,
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index fe90879b62..7de422128f 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -65,9 +65,12 @@ use rustc_hash::{FxHashMap, FxHashSet};
 use test_utils::tested_by;
 
 use crate::{
-    diagnostics::DiagnosticSink, either::Either, ids::MacroDefId,
-    nameres::diagnostics::DefDiagnostic, AstDatabase, AstId, BuiltinType, Crate, DefDatabase,
-    HirFileId, MacroDef, Module, ModuleDef, Name, Path, PathKind, Trait,
+    db::{AstDatabase, DefDatabase},
+    diagnostics::DiagnosticSink,
+    either::Either,
+    ids::MacroDefId,
+    nameres::diagnostics::DefDiagnostic,
+    AstId, BuiltinType, Crate, HirFileId, MacroDef, Module, ModuleDef, Name, Path, PathKind, Trait,
 };
 
 pub(crate) use self::raw::{ImportSourceMap, RawItems};
@@ -516,9 +519,10 @@ mod diagnostics {
     use relative_path::RelativePathBuf;
 
     use crate::{
+        db::{AstDatabase, DefDatabase},
         diagnostics::{DiagnosticSink, UnresolvedModule},
         nameres::CrateModuleId,
-        AstDatabase, AstId, DefDatabase,
+        AstId,
     };
 
     #[derive(Debug, PartialEq, Eq)]
diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
index 34b90a666c..1c0d4369e4 100644
--- a/crates/ra_hir/src/nameres/collector.rs
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -4,6 +4,7 @@ use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
 use crate::{
+    db::DefDatabase,
     either::Either,
     ids::{AstItemDef, LocationCtx, MacroCallId, MacroCallLoc, MacroDefId, MacroFileKind},
     name::MACRO_RULES,
@@ -13,8 +14,8 @@ use crate::{
         raw, CrateDefMap, CrateModuleId, ItemOrMacro, ModuleData, ModuleDef, PerNs,
         ReachedFixedPoint, Resolution, ResolveMode,
     },
-    AstId, Const, DefDatabase, Enum, Function, HirFileId, MacroDef, Module, Name, Path, Static,
-    Struct, Trait, TypeAlias, Union,
+    AstId, Const, Enum, Function, HirFileId, MacroDef, Module, Name, Path, Static, Struct, Trait,
+    TypeAlias, Union,
 };
 
 pub(super) fn collect_defs(db: &impl DefDatabase, mut def_map: CrateDefMap) -> CrateDefMap {
@@ -699,7 +700,7 @@ mod tests {
     use ra_db::SourceDatabase;
 
     use super::*;
-    use crate::{mock::MockDatabase, Crate, DefDatabase};
+    use crate::{db::DefDatabase, mock::MockDatabase, Crate};
     use ra_arena::Arena;
     use rustc_hash::FxHashSet;
 
diff --git a/crates/ra_hir/src/nameres/mod_resolution.rs b/crates/ra_hir/src/nameres/mod_resolution.rs
index 918c9591f5..a9e9eb9e65 100644
--- a/crates/ra_hir/src/nameres/mod_resolution.rs
+++ b/crates/ra_hir/src/nameres/mod_resolution.rs
@@ -6,7 +6,7 @@ use ra_db::{FileId, SourceRoot};
 use ra_syntax::SmolStr;
 use relative_path::RelativePathBuf;
 
-use crate::{DefDatabase, HirFileId, Name};
+use crate::{db::DefDatabase, HirFileId, Name};
 
 #[derive(Clone, Copy)]
 pub(super) struct ParentModule<'a> {
diff --git a/crates/ra_hir/src/nameres/raw.rs b/crates/ra_hir/src/nameres/raw.rs
index 129b047eb5..7963736e0d 100644
--- a/crates/ra_hir/src/nameres/raw.rs
+++ b/crates/ra_hir/src/nameres/raw.rs
@@ -8,8 +8,8 @@ use ra_syntax::{
 use test_utils::tested_by;
 
 use crate::{
-    AsName, AstDatabase, AstIdMap, DefDatabase, Either, FileAstId, HirFileId, ModuleSource, Name,
-    Path,
+    db::{AstDatabase, DefDatabase},
+    AsName, AstIdMap, Either, FileAstId, HirFileId, ModuleSource, Name, Path,
 };
 
 /// `RawItems` is a set of top-level items in a file (except for impls).
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index fdbe5e8b05..afdcd5415b 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -18,6 +18,7 @@ use ra_syntax::{
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
+    db::HirDatabase,
     expr::{
         self,
         scope::{ExprScopes, ScopeId},
@@ -27,9 +28,8 @@ use crate::{
     name,
     path::{PathKind, PathSegment},
     ty::method_resolution::implements_trait,
-    AsName, AstId, Const, Crate, DefWithBody, Either, Enum, Function, HasBody, HirDatabase,
-    HirFileId, MacroDef, Module, ModuleDef, Name, Path, PerNs, Resolution, Resolver, Static,
-    Struct, Trait, Ty,
+    AsName, AstId, Const, Crate, DefWithBody, Either, Enum, Function, HasBody, HirFileId, MacroDef,
+    Module, ModuleDef, Name, Path, PerNs, Resolution, Resolver, Static, Struct, Trait, Ty,
 };
 
 /// Locates the module by `FileId`. Picks topmost module in the file.
diff --git a/crates/ra_hir/src/source_id.rs b/crates/ra_hir/src/source_id.rs
index 51cd65ddad..04574876da 100644
--- a/crates/ra_hir/src/source_id.rs
+++ b/crates/ra_hir/src/source_id.rs
@@ -7,7 +7,7 @@ use std::{
 use ra_arena::{impl_arena_id, Arena, RawId};
 use ra_syntax::{ast, AstNode, SyntaxNode, SyntaxNodePtr};
 
-use crate::{AstDatabase, HirFileId};
+use crate::{db::AstDatabase, HirFileId};
 
 /// `AstId` points to an AST node in any file.
 ///
diff --git a/crates/ra_hir/src/traits.rs b/crates/ra_hir/src/traits.rs
index 6cdd3020af..4c2f7980dd 100644
--- a/crates/ra_hir/src/traits.rs
+++ b/crates/ra_hir/src/traits.rs
@@ -6,8 +6,10 @@ use std::sync::Arc;
 use ra_syntax::ast::{self, NameOwner};
 
 use crate::{
-    ids::LocationCtx, name::AsName, AstDatabase, Const, DefDatabase, Function, HasSource, Module,
-    Name, Trait, TypeAlias,
+    db::{AstDatabase, DefDatabase},
+    ids::LocationCtx,
+    name::AsName,
+    Const, Function, HasSource, Module, Name, Trait, TypeAlias,
 };
 
 #[derive(Debug, Clone, PartialEq, Eq)]
diff --git a/crates/ra_hir/src/ty/autoderef.rs b/crates/ra_hir/src/ty/autoderef.rs
index caa17f64ea..5ba7cf2e0f 100644
--- a/crates/ra_hir/src/ty/autoderef.rs
+++ b/crates/ra_hir/src/ty/autoderef.rs
@@ -8,7 +8,7 @@ use std::iter::successors;
 use log::{info, warn};
 
 use super::{traits::Solution, Canonical, Ty, TypeWalk};
-use crate::{name, HasGenericParams, HirDatabase, Resolver};
+use crate::{db::HirDatabase, name, HasGenericParams, Resolver};
 
 const AUTODEREF_RECURSION_LIMIT: usize = 10;
 
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index 0e6ebd3652..9244ff3cb9 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -35,6 +35,7 @@ use super::{
 use crate::{
     adt::VariantDef,
     code_model::{ModuleDef::Trait, TypeAlias},
+    db::HirDatabase,
     diagnostics::DiagnosticSink,
     expr::{
         self, Array, BinaryOp, BindingAnnotation, Body, Expr, ExprId, Literal, Pat, PatId,
@@ -50,8 +51,8 @@ use crate::{
     },
     ty::infer::diagnostics::InferenceDiagnostic,
     type_ref::{Mutability, TypeRef},
-    AdtDef, ConstData, DefWithBody, FnData, Function, HasBody, HirDatabase, ImplItem, ModuleDef,
-    Name, Path, StructField,
+    AdtDef, ConstData, DefWithBody, FnData, Function, HasBody, ImplItem, ModuleDef, Name, Path,
+    StructField,
 };
 
 mod unify;
@@ -1614,9 +1615,10 @@ impl Expectation {
 
 mod diagnostics {
     use crate::{
+        db::HirDatabase,
         diagnostics::{DiagnosticSink, NoSuchField},
         expr::ExprId,
-        Function, HasSource, HirDatabase,
+        Function, HasSource,
     };
 
     #[derive(Debug, PartialEq, Eq, Clone)]
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
index 480bae7401..0612298423 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir/src/ty/lower.rs
@@ -14,6 +14,7 @@ use super::{
 };
 use crate::{
     adt::VariantDef,
+    db::HirDatabase,
     generics::HasGenericParams,
     generics::{GenericDef, WherePredicate},
     nameres::Namespace,
@@ -21,8 +22,8 @@ use crate::{
     resolve::{Resolution, Resolver},
     ty::AdtDef,
     type_ref::{TypeBound, TypeRef},
-    BuiltinType, Const, Enum, EnumVariant, Function, HirDatabase, ModuleDef, Path, Static, Struct,
-    StructField, Trait, TypeAlias, Union,
+    BuiltinType, Const, Enum, EnumVariant, Function, ModuleDef, Path, Static, Struct, StructField,
+    Trait, TypeAlias, Union,
 };
 
 impl Ty {
diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir/src/ty/method_resolution.rs
index cf787bdaad..be63806d43 100644
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ b/crates/ra_hir/src/ty/method_resolution.rs
@@ -9,6 +9,7 @@ use rustc_hash::FxHashMap;
 
 use super::{autoderef, lower, Canonical, InEnvironment, TraitEnvironment, TraitRef};
 use crate::{
+    db::HirDatabase,
     generics::HasGenericParams,
     impl_block::{ImplBlock, ImplId, ImplItem},
     nameres::CrateModuleId,
@@ -16,7 +17,7 @@ use crate::{
     traits::TraitItem,
     ty::primitive::{FloatBitness, UncertainFloatTy, UncertainIntTy},
     ty::{Ty, TypeCtor},
-    Crate, Function, HirDatabase, Module, Name, Trait,
+    Crate, Function, Module, Name, Trait,
 };
 
 /// This is used as a key for indexing impls.