diff --git a/go/codeql-extractor.yml b/go/codeql-extractor.yml
index af9fca0462f3..7a009fb2610f 100644
--- a/go/codeql-extractor.yml
+++ b/go/codeql-extractor.yml
@@ -21,6 +21,7 @@ file_types:
     extensions:
       - .go
 legacy_qltest_extraction: true
+overlay_support_version: 20250626
 options:
   extract_tests:
     title: Whether to include Go test files in the CodeQL database.
diff --git a/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/go.dbscheme b/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/go.dbscheme
new file mode 100644
index 000000000000..b3da71c3ac20
--- /dev/null
+++ b/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/go.dbscheme
@@ -0,0 +1,552 @@
+/** Auto-generated dbscheme; do not edit. Run `make gen` in directory `go/` to regenerate. */
+
+
+/** Duplicate code **/
+
+duplicateCode(
+  unique int id : @duplication,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+similarCode(
+  unique int id : @similarity,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+@duplication_or_similarity = @duplication | @similarity;
+
+tokens(
+  int id : @duplication_or_similarity ref,
+  int offset : int ref,
+  int beginLine : int ref,
+  int beginColumn : int ref,
+  int endLine : int ref,
+  int endColumn : int ref);
+
+/** External data **/
+
+externalData(
+  int id : @externalDataElement,
+  varchar(900) path : string ref,
+  int column: int ref,
+  varchar(900) value : string ref
+);
+
+snapshotDate(unique date snapshotDate : date ref);
+
+sourceLocationPrefix(varchar(900) prefix : string ref);
+
+
+/*
+ * XML Files
+ */
+
+xmlEncoding(
+  unique int id: @file ref,
+  string encoding: string ref
+);
+
+xmlDTDs(
+  unique int id: @xmldtd,
+  string root: string ref,
+  string publicId: string ref,
+  string systemId: string ref,
+  int fileid: @file ref
+);
+
+xmlElements(
+  unique int id: @xmlelement,
+  string name: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int fileid: @file ref
+);
+
+xmlAttrs(
+  unique int id: @xmlattribute,
+  int elementid: @xmlelement ref,
+  string name: string ref,
+  string value: string ref,
+  int idx: int ref,
+  int fileid: @file ref
+);
+
+xmlNs(
+  int id: @xmlnamespace,
+  string prefixName: string ref,
+  string URI: string ref,
+  int fileid: @file ref
+);
+
+xmlHasNs(
+  int elementId: @xmlnamespaceable ref,
+  int nsId: @xmlnamespace ref,
+  int fileid: @file ref
+);
+
+xmlComments(
+  unique int id: @xmlcomment,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int fileid: @file ref
+);
+
+xmlChars(
+  unique int id: @xmlcharacters,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int isCDATA: int ref,
+  int fileid: @file ref
+);
+
+@xmlparent = @file | @xmlelement;
+@xmlnamespaceable = @xmlelement | @xmlattribute;
+
+xmllocations(
+  int xmlElement: @xmllocatable ref,
+  int location: @location_default ref
+);
+
+@xmllocatable = @xmlcharacters | @xmlelement | @xmlcomment | @xmlattribute | @xmldtd | @file | @xmlnamespace;
+
+compilations(unique int id: @compilation, string cwd: string ref);
+
+#keyset[id, num]
+compilation_args(int id: @compilation ref, int num: int ref, string arg: string ref);
+
+#keyset[id, num, kind]
+compilation_time(int id: @compilation ref, int num: int ref, int kind: int ref, float secs: float ref);
+
+diagnostic_for(unique int diagnostic: @diagnostic ref, int compilation: @compilation ref, int file_number: int ref, int file_number_diagnostic_number: int ref);
+
+compilation_finished(unique int id: @compilation ref, float cpu_seconds: float ref, float elapsed_seconds: float ref);
+
+#keyset[id, num]
+compilation_compiling_files(int id: @compilation ref, int num: int ref, int file: @file ref);
+
+diagnostics(unique int id: @diagnostic, int severity: int ref, string error_tag: string ref, string error_message: string ref,
+            string full_error_message: string ref, int location: @location ref);
+
+locations_default(unique int id: @location_default, int file: @file ref, int beginLine: int ref, int beginColumn: int ref,
+                  int endLine: int ref, int endColumn: int ref);
+
+numlines(int element_id: @sourceline ref, int num_lines: int ref, int num_code: int ref, int num_comment: int ref);
+
+files(unique int id: @file, string name: string ref);
+
+folders(unique int id: @folder, string name: string ref);
+
+containerparent(int parent: @container ref, unique int child: @container ref);
+
+has_location(unique int locatable: @locatable ref, int location: @location ref);
+
+#keyset[parent, idx]
+comment_groups(unique int id: @comment_group, int parent: @file ref, int idx: int ref);
+
+comments(unique int id: @comment, int kind: int ref, int parent: @comment_group ref, int idx: int ref, string text: string ref);
+
+doc_comments(unique int node: @documentable ref, int comment: @comment_group ref);
+
+#keyset[parent, idx]
+exprs(unique int id: @expr, int kind: int ref, int parent: @exprparent ref, int idx: int ref);
+
+literals(unique int expr: @expr ref, string value: string ref, string raw: string ref);
+
+constvalues(unique int expr: @expr ref, string value: string ref, string exact: string ref);
+
+fields(unique int id: @field, int parent: @fieldparent ref, int idx: int ref);
+
+typeparamdecls(unique int id: @typeparamdecl, int parent: @typeparamdeclparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+stmts(unique int id: @stmt, int kind: int ref, int parent: @stmtparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+decls(unique int id: @decl, int kind: int ref, int parent: @declparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+specs(unique int id: @spec, int kind: int ref, int parent: @gendecl ref, int idx: int ref);
+
+scopes(unique int id: @scope, int kind: int ref);
+
+scopenesting(unique int inner: @scope ref, int outer: @scope ref);
+
+scopenodes(unique int node: @scopenode ref, int scope: @localscope ref);
+
+objects(unique int id: @object, int kind: int ref, string name: string ref);
+
+objectscopes(unique int object: @object ref, int scope: @scope ref);
+
+objecttypes(unique int object: @object ref, int tp: @type ref);
+
+methodreceivers(unique int method: @object ref, int receiver: @object ref);
+
+fieldstructs(unique int field: @object ref, int struct: @structtype ref);
+
+methodhosts(int method: @object ref, int host: @definedtype ref);
+
+defs(int ident: @ident ref, int object: @object ref);
+
+uses(int ident: @ident ref, int object: @object ref);
+
+types(unique int id: @type, int kind: int ref);
+
+type_of(unique int expr: @expr ref, int tp: @type ref);
+
+typename(unique int tp: @type ref, string name: string ref);
+
+key_type(unique int map: @maptype ref, int tp: @type ref);
+
+element_type(unique int container: @containertype ref, int tp: @type ref);
+
+base_type(unique int ptr: @pointertype ref, int tp: @type ref);
+
+underlying_type(unique int defined: @definedtype ref, int tp: @type ref);
+
+#keyset[parent, index]
+component_types(int parent: @compositetype ref, int index: int ref, string name: string ref, int tp: @type ref);
+
+#keyset[parent, index]
+struct_tags(int parent: @structtype ref, int index: int ref, string tag: string ref);
+
+#keyset[interface, index]
+interface_private_method_ids(int interface: @interfacetype ref, int index: int ref, string id: string ref);
+
+array_length(unique int tp: @arraytype ref, string len: string ref);
+
+type_objects(unique int tp: @type ref, int object: @object ref);
+
+packages(unique int id: @package, string name: string ref, string path: string ref, int scope: @packagescope ref);
+
+#keyset[parent, idx]
+modexprs(unique int id: @modexpr, int kind: int ref, int parent: @modexprparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+modtokens(string token: string ref, int parent: @modexpr ref, int idx: int ref);
+
+#keyset[package, idx]
+errors(unique int id: @error, int kind: int ref, string msg: string ref, string rawpos: string ref,
+       string file: string ref, int line: int ref, int col: int ref, int package: @package ref, int idx: int ref);
+
+has_ellipsis(int id: @callorconversionexpr ref);
+
+variadic(int id: @signaturetype ref);
+
+#keyset[parent, idx]
+typeparam(unique int tp: @typeparamtype ref, string name: string ref, int bound: @compositetype ref,
+          int parent: @typeparamparentobject ref, int idx: int ref);
+
+@container = @file | @folder;
+
+@locatable = @xmllocatable | @node | @localscope;
+
+@node = @documentable | @exprparent | @modexprparent | @fieldparent | @stmtparent | @declparent | @typeparamdeclparent
+      | @scopenode | @comment_group | @comment;
+
+@documentable = @file | @field | @typeparamdecl | @spec | @gendecl | @funcdecl | @modexpr;
+
+@exprparent = @funcdef | @file | @expr | @field | @stmt | @decl | @typeparamdecl | @spec;
+
+@modexprparent = @file | @modexpr;
+
+@fieldparent = @decl | @structtypeexpr | @functypeexpr | @interfacetypeexpr;
+
+@stmtparent = @funcdef | @stmt | @decl;
+
+@declparent = @file | @declstmt;
+
+@typeparamdeclparent = @funcdecl | @typespec;
+
+@funcdef = @funclit | @funcdecl;
+
+@scopenode = @file | @functypeexpr | @blockstmt | @ifstmt | @caseclause | @switchstmt | @commclause | @loopstmt;
+
+@location = @location_default;
+
+@sourceline = @locatable;
+
+case @comment.kind of
+  0 = @slashslashcomment
+| 1 = @slashstarcomment;
+
+case @expr.kind of
+  0 = @badexpr
+| 1 = @ident
+| 2 = @ellipsis
+| 3 = @intlit
+| 4 = @floatlit
+| 5 = @imaglit
+| 6 = @charlit
+| 7 = @stringlit
+| 8 = @funclit
+| 9 = @compositelit
+| 10 = @parenexpr
+| 11 = @selectorexpr
+| 12 = @indexexpr
+| 13 = @genericfunctioninstantiationexpr
+| 14 = @generictypeinstantiationexpr
+| 15 = @sliceexpr
+| 16 = @typeassertexpr
+| 17 = @callorconversionexpr
+| 18 = @starexpr
+| 19 = @keyvalueexpr
+| 20 = @arraytypeexpr
+| 21 = @structtypeexpr
+| 22 = @functypeexpr
+| 23 = @interfacetypeexpr
+| 24 = @maptypeexpr
+| 25 = @typesetliteralexpr
+| 26 = @plusexpr
+| 27 = @minusexpr
+| 28 = @notexpr
+| 29 = @complementexpr
+| 30 = @derefexpr
+| 31 = @addressexpr
+| 32 = @arrowexpr
+| 33 = @lorexpr
+| 34 = @landexpr
+| 35 = @eqlexpr
+| 36 = @neqexpr
+| 37 = @lssexpr
+| 38 = @leqexpr
+| 39 = @gtrexpr
+| 40 = @geqexpr
+| 41 = @addexpr
+| 42 = @subexpr
+| 43 = @orexpr
+| 44 = @xorexpr
+| 45 = @mulexpr
+| 46 = @quoexpr
+| 47 = @remexpr
+| 48 = @shlexpr
+| 49 = @shrexpr
+| 50 = @andexpr
+| 51 = @andnotexpr
+| 52 = @sendchantypeexpr
+| 53 = @recvchantypeexpr
+| 54 = @sendrcvchantypeexpr;
+
+@basiclit = @intlit | @floatlit | @imaglit | @charlit | @stringlit;
+
+@operatorexpr = @logicalexpr | @arithmeticexpr | @bitwiseexpr | @unaryexpr | @binaryexpr;
+
+@logicalexpr = @logicalunaryexpr | @logicalbinaryexpr;
+
+@arithmeticexpr = @arithmeticunaryexpr | @arithmeticbinaryexpr;
+
+@bitwiseexpr = @bitwiseunaryexpr | @bitwisebinaryexpr;
+
+@unaryexpr = @logicalunaryexpr | @bitwiseunaryexpr | @arithmeticunaryexpr | @derefexpr | @addressexpr | @arrowexpr;
+
+@logicalunaryexpr = @notexpr;
+
+@bitwiseunaryexpr = @complementexpr;
+
+@arithmeticunaryexpr = @plusexpr | @minusexpr;
+
+@binaryexpr = @logicalbinaryexpr | @bitwisebinaryexpr | @arithmeticbinaryexpr | @comparison;
+
+@logicalbinaryexpr = @lorexpr | @landexpr;
+
+@bitwisebinaryexpr = @shiftexpr | @orexpr | @xorexpr | @andexpr | @andnotexpr;
+
+@arithmeticbinaryexpr = @addexpr | @subexpr | @mulexpr | @quoexpr | @remexpr;
+
+@shiftexpr = @shlexpr | @shrexpr;
+
+@comparison = @equalitytest | @relationalcomparison;
+
+@equalitytest = @eqlexpr | @neqexpr;
+
+@relationalcomparison = @lssexpr | @leqexpr | @gtrexpr | @geqexpr;
+
+@chantypeexpr = @sendchantypeexpr | @recvchantypeexpr | @sendrcvchantypeexpr;
+
+case @stmt.kind of
+  0 = @badstmt
+| 1 = @declstmt
+| 2 = @emptystmt
+| 3 = @labeledstmt
+| 4 = @exprstmt
+| 5 = @sendstmt
+| 6 = @incstmt
+| 7 = @decstmt
+| 8 = @gostmt
+| 9 = @deferstmt
+| 10 = @returnstmt
+| 11 = @breakstmt
+| 12 = @continuestmt
+| 13 = @gotostmt
+| 14 = @fallthroughstmt
+| 15 = @blockstmt
+| 16 = @ifstmt
+| 17 = @caseclause
+| 18 = @exprswitchstmt
+| 19 = @typeswitchstmt
+| 20 = @commclause
+| 21 = @selectstmt
+| 22 = @forstmt
+| 23 = @rangestmt
+| 24 = @assignstmt
+| 25 = @definestmt
+| 26 = @addassignstmt
+| 27 = @subassignstmt
+| 28 = @mulassignstmt
+| 29 = @quoassignstmt
+| 30 = @remassignstmt
+| 31 = @andassignstmt
+| 32 = @orassignstmt
+| 33 = @xorassignstmt
+| 34 = @shlassignstmt
+| 35 = @shrassignstmt
+| 36 = @andnotassignstmt;
+
+@incdecstmt = @incstmt | @decstmt;
+
+@assignment = @simpleassignstmt | @compoundassignstmt;
+
+@simpleassignstmt = @assignstmt | @definestmt;
+
+@compoundassignstmt = @addassignstmt | @subassignstmt | @mulassignstmt | @quoassignstmt | @remassignstmt
+                    | @andassignstmt | @orassignstmt | @xorassignstmt | @shlassignstmt | @shrassignstmt | @andnotassignstmt;
+
+@branchstmt = @breakstmt | @continuestmt | @gotostmt | @fallthroughstmt;
+
+@switchstmt = @exprswitchstmt | @typeswitchstmt;
+
+@loopstmt = @forstmt | @rangestmt;
+
+case @decl.kind of
+  0 = @baddecl
+| 1 = @importdecl
+| 2 = @constdecl
+| 3 = @typedecl
+| 4 = @vardecl
+| 5 = @funcdecl;
+
+@gendecl = @importdecl | @constdecl | @typedecl | @vardecl;
+
+case @spec.kind of
+  0 = @importspec
+| 1 = @valuespec
+| 2 = @typedefspec
+| 3 = @aliasspec;
+
+@typespec = @typedefspec | @aliasspec;
+
+case @object.kind of
+  0 = @pkgobject
+| 1 = @decltypeobject
+| 2 = @builtintypeobject
+| 3 = @declconstobject
+| 4 = @builtinconstobject
+| 5 = @declvarobject
+| 6 = @declfunctionobject
+| 7 = @builtinfunctionobject
+| 8 = @labelobject;
+
+@typeparamparentobject = @decltypeobject | @declfunctionobject;
+
+@declobject = @decltypeobject | @declconstobject | @declvarobject | @declfunctionobject;
+
+@builtinobject = @builtintypeobject | @builtinconstobject | @builtinfunctionobject;
+
+@typeobject = @decltypeobject | @builtintypeobject;
+
+@valueobject = @constobject | @varobject | @functionobject;
+
+@constobject = @declconstobject | @builtinconstobject;
+
+@varobject = @declvarobject;
+
+@functionobject = @declfunctionobject | @builtinfunctionobject;
+
+case @scope.kind of
+  0 = @universescope
+| 1 = @packagescope
+| 2 = @localscope;
+
+case @type.kind of
+  0 = @invalidtype
+| 1 = @boolexprtype
+| 2 = @inttype
+| 3 = @int8type
+| 4 = @int16type
+| 5 = @int32type
+| 6 = @int64type
+| 7 = @uinttype
+| 8 = @uint8type
+| 9 = @uint16type
+| 10 = @uint32type
+| 11 = @uint64type
+| 12 = @uintptrtype
+| 13 = @float32type
+| 14 = @float64type
+| 15 = @complex64type
+| 16 = @complex128type
+| 17 = @stringexprtype
+| 18 = @unsafepointertype
+| 19 = @boolliteraltype
+| 20 = @intliteraltype
+| 21 = @runeliteraltype
+| 22 = @floatliteraltype
+| 23 = @complexliteraltype
+| 24 = @stringliteraltype
+| 25 = @nilliteraltype
+| 26 = @typeparamtype
+| 27 = @arraytype
+| 28 = @slicetype
+| 29 = @structtype
+| 30 = @pointertype
+| 31 = @interfacetype
+| 32 = @tupletype
+| 33 = @signaturetype
+| 34 = @maptype
+| 35 = @sendchantype
+| 36 = @recvchantype
+| 37 = @sendrcvchantype
+| 38 = @definedtype
+| 39 = @typesetliteraltype;
+
+@basictype = @booltype | @numerictype | @stringtype | @literaltype | @invalidtype | @unsafepointertype;
+
+@booltype = @boolexprtype | @boolliteraltype;
+
+@numerictype = @integertype | @floattype | @complextype;
+
+@integertype = @signedintegertype | @unsignedintegertype;
+
+@signedintegertype = @inttype | @int8type | @int16type | @int32type | @int64type | @intliteraltype | @runeliteraltype;
+
+@unsignedintegertype = @uinttype | @uint8type | @uint16type | @uint32type | @uint64type | @uintptrtype;
+
+@floattype = @float32type | @float64type | @floatliteraltype;
+
+@complextype = @complex64type | @complex128type | @complexliteraltype;
+
+@stringtype = @stringexprtype | @stringliteraltype;
+
+@literaltype = @boolliteraltype | @intliteraltype | @runeliteraltype | @floatliteraltype | @complexliteraltype
+             | @stringliteraltype | @nilliteraltype;
+
+@compositetype = @typeparamtype | @containertype | @structtype | @pointertype | @interfacetype | @tupletype
+               | @signaturetype | @definedtype | @typesetliteraltype;
+
+@containertype = @arraytype | @slicetype | @maptype | @chantype;
+
+@chantype = @sendchantype | @recvchantype | @sendrcvchantype;
+
+case @modexpr.kind of
+  0 = @modcommentblock
+| 1 = @modline
+| 2 = @modlineblock
+| 3 = @modlparen
+| 4 = @modrparen;
+
+case @error.kind of
+  0 = @unknownerror
+| 1 = @listerror
+| 2 = @parseerror
+| 3 = @typeerror;
+
diff --git a/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/old.dbscheme b/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/old.dbscheme
new file mode 100644
index 000000000000..b1341734d687
--- /dev/null
+++ b/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/old.dbscheme
@@ -0,0 +1,563 @@
+/** Auto-generated dbscheme; do not edit. Run `make gen` in directory `go/` to regenerate. */
+
+
+/** Duplicate code **/
+
+duplicateCode(
+  unique int id : @duplication,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+similarCode(
+  unique int id : @similarity,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+@duplication_or_similarity = @duplication | @similarity;
+
+tokens(
+  int id : @duplication_or_similarity ref,
+  int offset : int ref,
+  int beginLine : int ref,
+  int beginColumn : int ref,
+  int endLine : int ref,
+  int endColumn : int ref);
+
+/** External data **/
+
+externalData(
+  int id : @externalDataElement,
+  varchar(900) path : string ref,
+  int column: int ref,
+  varchar(900) value : string ref
+);
+
+snapshotDate(unique date snapshotDate : date ref);
+
+sourceLocationPrefix(varchar(900) prefix : string ref);
+
+/** Overlay support **/
+
+databaseMetadata(
+  string metadataKey: string ref,
+  string value: string ref
+);
+
+overlayChangedFiles(
+  string path: string ref
+);
+
+
+/*
+ * XML Files
+ */
+
+xmlEncoding(
+  unique int id: @file ref,
+  string encoding: string ref
+);
+
+xmlDTDs(
+  unique int id: @xmldtd,
+  string root: string ref,
+  string publicId: string ref,
+  string systemId: string ref,
+  int fileid: @file ref
+);
+
+xmlElements(
+  unique int id: @xmlelement,
+  string name: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int fileid: @file ref
+);
+
+xmlAttrs(
+  unique int id: @xmlattribute,
+  int elementid: @xmlelement ref,
+  string name: string ref,
+  string value: string ref,
+  int idx: int ref,
+  int fileid: @file ref
+);
+
+xmlNs(
+  int id: @xmlnamespace,
+  string prefixName: string ref,
+  string URI: string ref,
+  int fileid: @file ref
+);
+
+xmlHasNs(
+  int elementId: @xmlnamespaceable ref,
+  int nsId: @xmlnamespace ref,
+  int fileid: @file ref
+);
+
+xmlComments(
+  unique int id: @xmlcomment,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int fileid: @file ref
+);
+
+xmlChars(
+  unique int id: @xmlcharacters,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int isCDATA: int ref,
+  int fileid: @file ref
+);
+
+@xmlparent = @file | @xmlelement;
+@xmlnamespaceable = @xmlelement | @xmlattribute;
+
+xmllocations(
+  int xmlElement: @xmllocatable ref,
+  int location: @location_default ref
+);
+
+@xmllocatable = @xmlcharacters | @xmlelement | @xmlcomment | @xmlattribute | @xmldtd | @file | @xmlnamespace;
+
+compilations(unique int id: @compilation, string cwd: string ref);
+
+#keyset[id, num]
+compilation_args(int id: @compilation ref, int num: int ref, string arg: string ref);
+
+#keyset[id, num, kind]
+compilation_time(int id: @compilation ref, int num: int ref, int kind: int ref, float secs: float ref);
+
+diagnostic_for(unique int diagnostic: @diagnostic ref, int compilation: @compilation ref, int file_number: int ref, int file_number_diagnostic_number: int ref);
+
+compilation_finished(unique int id: @compilation ref, float cpu_seconds: float ref, float elapsed_seconds: float ref);
+
+#keyset[id, num]
+compilation_compiling_files(int id: @compilation ref, int num: int ref, int file: @file ref);
+
+diagnostics(unique int id: @diagnostic, int severity: int ref, string error_tag: string ref, string error_message: string ref,
+            string full_error_message: string ref, int location: @location ref);
+
+locations_default(unique int id: @location_default, int file: @file ref, int beginLine: int ref, int beginColumn: int ref,
+                  int endLine: int ref, int endColumn: int ref);
+
+numlines(int element_id: @sourceline ref, int num_lines: int ref, int num_code: int ref, int num_comment: int ref);
+
+files(unique int id: @file, string name: string ref);
+
+folders(unique int id: @folder, string name: string ref);
+
+containerparent(int parent: @container ref, unique int child: @container ref);
+
+has_location(unique int locatable: @locatable ref, int location: @location ref);
+
+#keyset[parent, idx]
+comment_groups(unique int id: @comment_group, int parent: @file ref, int idx: int ref);
+
+comments(unique int id: @comment, int kind: int ref, int parent: @comment_group ref, int idx: int ref, string text: string ref);
+
+doc_comments(unique int node: @documentable ref, int comment: @comment_group ref);
+
+#keyset[parent, idx]
+exprs(unique int id: @expr, int kind: int ref, int parent: @exprparent ref, int idx: int ref);
+
+literals(unique int expr: @expr ref, string value: string ref, string raw: string ref);
+
+constvalues(unique int expr: @expr ref, string value: string ref, string exact: string ref);
+
+fields(unique int id: @field, int parent: @fieldparent ref, int idx: int ref);
+
+typeparamdecls(unique int id: @typeparamdecl, int parent: @typeparamdeclparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+stmts(unique int id: @stmt, int kind: int ref, int parent: @stmtparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+decls(unique int id: @decl, int kind: int ref, int parent: @declparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+specs(unique int id: @spec, int kind: int ref, int parent: @gendecl ref, int idx: int ref);
+
+scopes(unique int id: @scope, int kind: int ref);
+
+scopenesting(unique int inner: @scope ref, int outer: @scope ref);
+
+scopenodes(unique int node: @scopenode ref, int scope: @localscope ref);
+
+objects(unique int id: @object, int kind: int ref, string name: string ref);
+
+objectscopes(unique int object: @object ref, int scope: @scope ref);
+
+objecttypes(unique int object: @object ref, int tp: @type ref);
+
+methodreceivers(unique int method: @object ref, int receiver: @object ref);
+
+fieldstructs(unique int field: @object ref, int struct: @structtype ref);
+
+methodhosts(int method: @object ref, int host: @definedtype ref);
+
+defs(int ident: @ident ref, int object: @object ref);
+
+uses(int ident: @ident ref, int object: @object ref);
+
+types(unique int id: @type, int kind: int ref);
+
+type_of(unique int expr: @expr ref, int tp: @type ref);
+
+typename(unique int tp: @type ref, string name: string ref);
+
+key_type(unique int map: @maptype ref, int tp: @type ref);
+
+element_type(unique int container: @containertype ref, int tp: @type ref);
+
+base_type(unique int ptr: @pointertype ref, int tp: @type ref);
+
+underlying_type(unique int defined: @definedtype ref, int tp: @type ref);
+
+#keyset[parent, index]
+component_types(int parent: @compositetype ref, int index: int ref, string name: string ref, int tp: @type ref);
+
+#keyset[parent, index]
+struct_tags(int parent: @structtype ref, int index: int ref, string tag: string ref);
+
+#keyset[interface, index]
+interface_private_method_ids(int interface: @interfacetype ref, int index: int ref, string id: string ref);
+
+array_length(unique int tp: @arraytype ref, string len: string ref);
+
+type_objects(unique int tp: @type ref, int object: @object ref);
+
+packages(unique int id: @package, string name: string ref, string path: string ref, int scope: @packagescope ref);
+
+#keyset[parent, idx]
+modexprs(unique int id: @modexpr, int kind: int ref, int parent: @modexprparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+modtokens(string token: string ref, int parent: @modexpr ref, int idx: int ref);
+
+#keyset[package, idx]
+errors(unique int id: @error, int kind: int ref, string msg: string ref, string rawpos: string ref,
+       string file: string ref, int line: int ref, int col: int ref, int package: @package ref, int idx: int ref);
+
+has_ellipsis(int id: @callorconversionexpr ref);
+
+variadic(int id: @signaturetype ref);
+
+#keyset[parent, idx]
+typeparam(unique int tp: @typeparamtype ref, string name: string ref, int bound: @compositetype ref,
+          int parent: @typeparamparentobject ref, int idx: int ref);
+
+@container = @file | @folder;
+
+@locatable = @xmllocatable | @node | @localscope;
+
+@node = @documentable | @exprparent | @modexprparent | @fieldparent | @stmtparent | @declparent | @typeparamdeclparent
+      | @scopenode | @comment_group | @comment;
+
+@documentable = @file | @field | @typeparamdecl | @spec | @gendecl | @funcdecl | @modexpr;
+
+@exprparent = @funcdef | @file | @expr | @field | @stmt | @decl | @typeparamdecl | @spec;
+
+@modexprparent = @file | @modexpr;
+
+@fieldparent = @decl | @structtypeexpr | @functypeexpr | @interfacetypeexpr;
+
+@stmtparent = @funcdef | @stmt | @decl;
+
+@declparent = @file | @declstmt;
+
+@typeparamdeclparent = @funcdecl | @typespec;
+
+@funcdef = @funclit | @funcdecl;
+
+@scopenode = @file | @functypeexpr | @blockstmt | @ifstmt | @caseclause | @switchstmt | @commclause | @loopstmt;
+
+@location = @location_default;
+
+@sourceline = @locatable;
+
+case @comment.kind of
+  0 = @slashslashcomment
+| 1 = @slashstarcomment;
+
+case @expr.kind of
+  0 = @badexpr
+| 1 = @ident
+| 2 = @ellipsis
+| 3 = @intlit
+| 4 = @floatlit
+| 5 = @imaglit
+| 6 = @charlit
+| 7 = @stringlit
+| 8 = @funclit
+| 9 = @compositelit
+| 10 = @parenexpr
+| 11 = @selectorexpr
+| 12 = @indexexpr
+| 13 = @genericfunctioninstantiationexpr
+| 14 = @generictypeinstantiationexpr
+| 15 = @sliceexpr
+| 16 = @typeassertexpr
+| 17 = @callorconversionexpr
+| 18 = @starexpr
+| 19 = @keyvalueexpr
+| 20 = @arraytypeexpr
+| 21 = @structtypeexpr
+| 22 = @functypeexpr
+| 23 = @interfacetypeexpr
+| 24 = @maptypeexpr
+| 25 = @typesetliteralexpr
+| 26 = @plusexpr
+| 27 = @minusexpr
+| 28 = @notexpr
+| 29 = @complementexpr
+| 30 = @derefexpr
+| 31 = @addressexpr
+| 32 = @arrowexpr
+| 33 = @lorexpr
+| 34 = @landexpr
+| 35 = @eqlexpr
+| 36 = @neqexpr
+| 37 = @lssexpr
+| 38 = @leqexpr
+| 39 = @gtrexpr
+| 40 = @geqexpr
+| 41 = @addexpr
+| 42 = @subexpr
+| 43 = @orexpr
+| 44 = @xorexpr
+| 45 = @mulexpr
+| 46 = @quoexpr
+| 47 = @remexpr
+| 48 = @shlexpr
+| 49 = @shrexpr
+| 50 = @andexpr
+| 51 = @andnotexpr
+| 52 = @sendchantypeexpr
+| 53 = @recvchantypeexpr
+| 54 = @sendrcvchantypeexpr;
+
+@basiclit = @intlit | @floatlit | @imaglit | @charlit | @stringlit;
+
+@operatorexpr = @logicalexpr | @arithmeticexpr | @bitwiseexpr | @unaryexpr | @binaryexpr;
+
+@logicalexpr = @logicalunaryexpr | @logicalbinaryexpr;
+
+@arithmeticexpr = @arithmeticunaryexpr | @arithmeticbinaryexpr;
+
+@bitwiseexpr = @bitwiseunaryexpr | @bitwisebinaryexpr;
+
+@unaryexpr = @logicalunaryexpr | @bitwiseunaryexpr | @arithmeticunaryexpr | @derefexpr | @addressexpr | @arrowexpr;
+
+@logicalunaryexpr = @notexpr;
+
+@bitwiseunaryexpr = @complementexpr;
+
+@arithmeticunaryexpr = @plusexpr | @minusexpr;
+
+@binaryexpr = @logicalbinaryexpr | @bitwisebinaryexpr | @arithmeticbinaryexpr | @comparison;
+
+@logicalbinaryexpr = @lorexpr | @landexpr;
+
+@bitwisebinaryexpr = @shiftexpr | @orexpr | @xorexpr | @andexpr | @andnotexpr;
+
+@arithmeticbinaryexpr = @addexpr | @subexpr | @mulexpr | @quoexpr | @remexpr;
+
+@shiftexpr = @shlexpr | @shrexpr;
+
+@comparison = @equalitytest | @relationalcomparison;
+
+@equalitytest = @eqlexpr | @neqexpr;
+
+@relationalcomparison = @lssexpr | @leqexpr | @gtrexpr | @geqexpr;
+
+@chantypeexpr = @sendchantypeexpr | @recvchantypeexpr | @sendrcvchantypeexpr;
+
+case @stmt.kind of
+  0 = @badstmt
+| 1 = @declstmt
+| 2 = @emptystmt
+| 3 = @labeledstmt
+| 4 = @exprstmt
+| 5 = @sendstmt
+| 6 = @incstmt
+| 7 = @decstmt
+| 8 = @gostmt
+| 9 = @deferstmt
+| 10 = @returnstmt
+| 11 = @breakstmt
+| 12 = @continuestmt
+| 13 = @gotostmt
+| 14 = @fallthroughstmt
+| 15 = @blockstmt
+| 16 = @ifstmt
+| 17 = @caseclause
+| 18 = @exprswitchstmt
+| 19 = @typeswitchstmt
+| 20 = @commclause
+| 21 = @selectstmt
+| 22 = @forstmt
+| 23 = @rangestmt
+| 24 = @assignstmt
+| 25 = @definestmt
+| 26 = @addassignstmt
+| 27 = @subassignstmt
+| 28 = @mulassignstmt
+| 29 = @quoassignstmt
+| 30 = @remassignstmt
+| 31 = @andassignstmt
+| 32 = @orassignstmt
+| 33 = @xorassignstmt
+| 34 = @shlassignstmt
+| 35 = @shrassignstmt
+| 36 = @andnotassignstmt;
+
+@incdecstmt = @incstmt | @decstmt;
+
+@assignment = @simpleassignstmt | @compoundassignstmt;
+
+@simpleassignstmt = @assignstmt | @definestmt;
+
+@compoundassignstmt = @addassignstmt | @subassignstmt | @mulassignstmt | @quoassignstmt | @remassignstmt
+                    | @andassignstmt | @orassignstmt | @xorassignstmt | @shlassignstmt | @shrassignstmt | @andnotassignstmt;
+
+@branchstmt = @breakstmt | @continuestmt | @gotostmt | @fallthroughstmt;
+
+@switchstmt = @exprswitchstmt | @typeswitchstmt;
+
+@loopstmt = @forstmt | @rangestmt;
+
+case @decl.kind of
+  0 = @baddecl
+| 1 = @importdecl
+| 2 = @constdecl
+| 3 = @typedecl
+| 4 = @vardecl
+| 5 = @funcdecl;
+
+@gendecl = @importdecl | @constdecl | @typedecl | @vardecl;
+
+case @spec.kind of
+  0 = @importspec
+| 1 = @valuespec
+| 2 = @typedefspec
+| 3 = @aliasspec;
+
+@typespec = @typedefspec | @aliasspec;
+
+case @object.kind of
+  0 = @pkgobject
+| 1 = @decltypeobject
+| 2 = @builtintypeobject
+| 3 = @declconstobject
+| 4 = @builtinconstobject
+| 5 = @declvarobject
+| 6 = @declfunctionobject
+| 7 = @builtinfunctionobject
+| 8 = @labelobject;
+
+@typeparamparentobject = @decltypeobject | @declfunctionobject;
+
+@declobject = @decltypeobject | @declconstobject | @declvarobject | @declfunctionobject;
+
+@builtinobject = @builtintypeobject | @builtinconstobject | @builtinfunctionobject;
+
+@typeobject = @decltypeobject | @builtintypeobject;
+
+@valueobject = @constobject | @varobject | @functionobject;
+
+@constobject = @declconstobject | @builtinconstobject;
+
+@varobject = @declvarobject;
+
+@functionobject = @declfunctionobject | @builtinfunctionobject;
+
+case @scope.kind of
+  0 = @universescope
+| 1 = @packagescope
+| 2 = @localscope;
+
+case @type.kind of
+  0 = @invalidtype
+| 1 = @boolexprtype
+| 2 = @inttype
+| 3 = @int8type
+| 4 = @int16type
+| 5 = @int32type
+| 6 = @int64type
+| 7 = @uinttype
+| 8 = @uint8type
+| 9 = @uint16type
+| 10 = @uint32type
+| 11 = @uint64type
+| 12 = @uintptrtype
+| 13 = @float32type
+| 14 = @float64type
+| 15 = @complex64type
+| 16 = @complex128type
+| 17 = @stringexprtype
+| 18 = @unsafepointertype
+| 19 = @boolliteraltype
+| 20 = @intliteraltype
+| 21 = @runeliteraltype
+| 22 = @floatliteraltype
+| 23 = @complexliteraltype
+| 24 = @stringliteraltype
+| 25 = @nilliteraltype
+| 26 = @typeparamtype
+| 27 = @arraytype
+| 28 = @slicetype
+| 29 = @structtype
+| 30 = @pointertype
+| 31 = @interfacetype
+| 32 = @tupletype
+| 33 = @signaturetype
+| 34 = @maptype
+| 35 = @sendchantype
+| 36 = @recvchantype
+| 37 = @sendrcvchantype
+| 38 = @definedtype
+| 39 = @typesetliteraltype;
+
+@basictype = @booltype | @numerictype | @stringtype | @literaltype | @invalidtype | @unsafepointertype;
+
+@booltype = @boolexprtype | @boolliteraltype;
+
+@numerictype = @integertype | @floattype | @complextype;
+
+@integertype = @signedintegertype | @unsignedintegertype;
+
+@signedintegertype = @inttype | @int8type | @int16type | @int32type | @int64type | @intliteraltype | @runeliteraltype;
+
+@unsignedintegertype = @uinttype | @uint8type | @uint16type | @uint32type | @uint64type | @uintptrtype;
+
+@floattype = @float32type | @float64type | @floatliteraltype;
+
+@complextype = @complex64type | @complex128type | @complexliteraltype;
+
+@stringtype = @stringexprtype | @stringliteraltype;
+
+@literaltype = @boolliteraltype | @intliteraltype | @runeliteraltype | @floatliteraltype | @complexliteraltype
+             | @stringliteraltype | @nilliteraltype;
+
+@compositetype = @typeparamtype | @containertype | @structtype | @pointertype | @interfacetype | @tupletype
+               | @signaturetype | @definedtype | @typesetliteraltype;
+
+@containertype = @arraytype | @slicetype | @maptype | @chantype;
+
+@chantype = @sendchantype | @recvchantype | @sendrcvchantype;
+
+case @modexpr.kind of
+  0 = @modcommentblock
+| 1 = @modline
+| 2 = @modlineblock
+| 3 = @modlparen
+| 4 = @modrparen;
+
+case @error.kind of
+  0 = @unknownerror
+| 1 = @listerror
+| 2 = @parseerror
+| 3 = @typeerror;
+
diff --git a/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/upgrade.properties b/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/upgrade.properties
new file mode 100644
index 000000000000..1a7cdb0ad716
--- /dev/null
+++ b/go/downgrades/b1341734d6870b105e5c9d168ce7dec25d7f72d0/upgrade.properties
@@ -0,0 +1,4 @@
+description: Add databaseMetadata and overlayChangedFiles relations
+compatibility: full
+databaseMetadata.rel: delete
+overlayChangedFiles.rel: delete
diff --git a/go/extractor/cli/go-autobuilder/BUILD.bazel b/go/extractor/cli/go-autobuilder/BUILD.bazel
index 0c705d5b1944..003836b08742 100644
--- a/go/extractor/cli/go-autobuilder/BUILD.bazel
+++ b/go/extractor/cli/go-autobuilder/BUILD.bazel
@@ -12,6 +12,7 @@ go_library(
         "//go/extractor/autobuilder",
         "//go/extractor/diagnostics",
         "//go/extractor/project",
+        "//go/extractor/srcarchive",
         "//go/extractor/toolchain",
         "//go/extractor/util",
     ],
diff --git a/go/extractor/cli/go-autobuilder/go-autobuilder.go b/go/extractor/cli/go-autobuilder/go-autobuilder.go
index ae9a478c3674..756bd19b45e9 100644
--- a/go/extractor/cli/go-autobuilder/go-autobuilder.go
+++ b/go/extractor/cli/go-autobuilder/go-autobuilder.go
@@ -13,6 +13,7 @@ import (
 	"github.com/github/codeql-go/extractor/autobuilder"
 	"github.com/github/codeql-go/extractor/diagnostics"
 	"github.com/github/codeql-go/extractor/project"
+	"github.com/github/codeql-go/extractor/srcarchive"
 	"github.com/github/codeql-go/extractor/toolchain"
 	"github.com/github/codeql-go/extractor/util"
 )
@@ -273,7 +274,7 @@ func createPathTransformerFile(newdir string) *os.File {
 		log.Fatalf("Failed to chdir into %s: %s\n", newdir, err.Error())
 	}
 
-	// set up SEMMLE_PATH_TRANSFORMER to ensure paths in the source archive and the snapshot
+	// set up CODEQL_PATH_TRANSFORMER to ensure paths in the source archive and the snapshot
 	// match the original source location, not the location we moved it to
 	pt, err := os.CreateTemp("", "path-transformer")
 	if err != nil {
@@ -283,7 +284,7 @@ func createPathTransformerFile(newdir string) *os.File {
 }
 
 // Writes the path transformer file
-func writePathTransformerFile(pt *os.File, realSrc, root, newdir string) {
+func writePathTransformerFile(pt *os.File, realSrc, newdir string) {
 	_, err := pt.WriteString("#" + realSrc + "\n" + newdir + "//\n")
 	if err != nil {
 		log.Fatalf("Unable to write path transformer file: %s.", err.Error())
@@ -292,9 +293,9 @@ func writePathTransformerFile(pt *os.File, realSrc, root, newdir string) {
 	if err != nil {
 		log.Fatalf("Unable to close path transformer file: %s.", err.Error())
 	}
-	err = os.Setenv("SEMMLE_PATH_TRANSFORMER", pt.Name())
+	err = os.Setenv("CODEQL_PATH_TRANSFORMER", pt.Name())
 	if err != nil {
-		log.Fatalf("Unable to set SEMMLE_PATH_TRANSFORMER environment variable: %s.\n", err.Error())
+		log.Fatalf("Unable to set CODEQL_PATH_TRANSFORMER environment variable: %s.\n", err.Error())
 	}
 }
 
@@ -447,7 +448,7 @@ func installDependencies(workspace project.GoWorkspace) {
 }
 
 // Run the extractor.
-func extract(workspace project.GoWorkspace) bool {
+func extract(workspace project.GoWorkspace, sourceRoot string) bool {
 	extractor, err := util.GetExtractorPath()
 	if err != nil {
 		log.Fatalf("Could not determine path of extractor: %v.\n", err)
@@ -458,6 +459,12 @@ func extract(workspace project.GoWorkspace) bool {
 		extractorArgs = append(extractorArgs, workspace.ModMode.ArgsForGoVersion(toolchain.GetEnvGoSemVer())...)
 	}
 
+	if util.IsOverlayExtraction() {
+		// When we are extracting an overlay, pass the source root to the extractor so that it knows
+		// how to resolve the relative paths in the list of changed files.
+		extractorArgs = append(extractorArgs, "--source-root", sourceRoot)
+	}
+
 	if len(workspace.Modules) == 0 {
 		// There may be no modules if we are using e.g. Dep or Glide
 		extractorArgs = append(extractorArgs, "./...")
@@ -501,9 +508,6 @@ func installDependenciesAndBuild() {
 
 	srcdir := getSourceDir()
 
-	// we set `SEMMLE_PATH_TRANSFORMER` ourselves in some cases, so blank it out first for consistency
-	os.Setenv("SEMMLE_PATH_TRANSFORMER", "")
-
 	// determine how to install dependencies and whether a GOPATH needs to be set up before
 	// extraction
 	workspaces := project.GetWorkspaceInfo(true)
@@ -534,7 +538,21 @@ func installDependenciesAndBuild() {
 			pt := createPathTransformerFile(paths.newdir)
 			defer os.Remove(pt.Name())
 
-			writePathTransformerFile(pt, paths.realSrc, paths.root, paths.newdir)
+			// We're about to create out own path transformer, so that paths containing the
+			// temporary GOPATH point to the right location. However, if there was already an
+			// incoming path transformer, the right location will be what _it_ wanted to transform
+			// paths to.
+			existingPathTransformer, err := srcarchive.LoadProjectLayoutFromEnv()
+			if err != nil {
+				log.Fatalf("Unable to load path transformer: %s.\n", err.Error())
+			}
+			var realSrc string
+			if existingPathTransformer == nil {
+				realSrc = paths.realSrc
+			} else {
+				realSrc = existingPathTransformer.To
+			}
+			writePathTransformerFile(pt, realSrc, paths.newdir)
 			setGopath(paths.root)
 		}
 	}
@@ -575,6 +593,12 @@ func installDependenciesAndBuild() {
 		buildWithCustomCommands(inst)
 	}
 
+	// The autobuilder is invoked with its working directory set to the source directory.
+	sourceRoot, err := os.Getwd()
+	if err != nil {
+		log.Fatalf("Failed to get current working directory: %s\n", err.Error())
+	}
+
 	// Attempt to extract all workspaces; we will tolerate individual extraction failures here
 	for i, workspace := range workspaces {
 		if workspace.ModMode == project.ModVendor {
@@ -595,7 +619,7 @@ func installDependenciesAndBuild() {
 			}
 		}
 
-		workspaces[i].Extracted = extract(workspace)
+		workspaces[i].Extracted = extract(workspace, sourceRoot)
 
 		if !workspaces[i].Extracted {
 			unsuccessfulProjects = append(unsuccessfulProjects, workspace.BaseDir)
@@ -620,6 +644,8 @@ func installDependenciesAndBuild() {
 	} else {
 		log.Printf("Success: extraction succeeded for all %d discovered project(s).\n", len(workspaces))
 	}
+
+	util.WriteOverlayBaseMetadata()
 }
 
 func main() {
diff --git a/go/extractor/cli/go-extractor/go-extractor.go b/go/extractor/cli/go-extractor/go-extractor.go
index 72ab3291f3cc..d394d5fde40e 100644
--- a/go/extractor/cli/go-extractor/go-extractor.go
+++ b/go/extractor/cli/go-extractor/go-extractor.go
@@ -24,9 +24,10 @@ func usage() {
 
 // extractTests is set (a) if we were manually commanded to extract tests via the relevant
 // environment variable / extractor option, or (b) we're mimicking a `go test` command.
-func parseFlags(args []string, mimic bool, extractTests bool) ([]string, []string, bool) {
+func parseFlags(args []string, mimic bool, extractTests bool) ([]string, []string, bool, string) {
 	i := 0
 	buildFlags := []string{}
+	var sourceRoot string
 	for ; i < len(args) && strings.HasPrefix(args[i], "-"); i++ {
 		if args[i] == "--" {
 			i++
@@ -61,6 +62,18 @@ func parseFlags(args []string, mimic bool, extractTests bool) ([]string, []strin
 				} else {
 					log.Fatalf("--mimic requires an argument, e.g. --mimic go")
 				}
+			case "--source-root":
+				// The extractor can be called by the autobuilder with the working directory set to
+				// the directory containing the workspace we're extracting, and this may be a
+				// subdirectory of the actual source root. This argument lets us resolve paths that
+				// are relative to that source root, e.g. for the list of overlay changed files.
+				if i+1 < len(args) {
+					i++
+					sourceRoot = args[i]
+					log.Printf("Source root is %s", sourceRoot)
+				} else {
+					log.Fatalf("--source-root requires an argument, e.g. --source-root /path/to/root")
+				}
 			}
 		}
 
@@ -93,14 +106,14 @@ func parseFlags(args []string, mimic bool, extractTests bool) ([]string, []strin
 	cpuprofile = os.Getenv("CODEQL_EXTRACTOR_GO_CPU_PROFILE")
 	memprofile = os.Getenv("CODEQL_EXTRACTOR_GO_MEM_PROFILE")
 
-	return buildFlags, args[i:], extractTests
+	return buildFlags, args[i:], extractTests, sourceRoot
 }
 
 func main() {
 	util.SetLogLevel()
 
 	extractTestsDefault := os.Getenv("CODEQL_EXTRACTOR_GO_OPTION_EXTRACT_TESTS") == "true"
-	buildFlags, patterns, extractTests := parseFlags(os.Args[1:], false, extractTestsDefault)
+	buildFlags, patterns, extractTests, sourceRoot := parseFlags(os.Args[1:], false, extractTestsDefault)
 
 	if cpuprofile != "" {
 		f, err := os.Create(cpuprofile)
@@ -120,7 +133,7 @@ func main() {
 	}
 
 	log.Printf("Build flags: '%s'; patterns: '%s'\n", strings.Join(buildFlags, " "), strings.Join(patterns, " "))
-	err := extractor.ExtractWithFlags(buildFlags, patterns, extractTests)
+	err := extractor.ExtractWithFlags(buildFlags, patterns, extractTests, sourceRoot)
 	if err != nil {
 		errString := err.Error()
 		if strings.Contains(errString, "unexpected directory layout:") {
diff --git a/go/extractor/dbscheme/tables.go b/go/extractor/dbscheme/tables.go
index 665ecdcc240f..9c537fbaf89f 100644
--- a/go/extractor/dbscheme/tables.go
+++ b/go/extractor/dbscheme/tables.go
@@ -43,6 +43,17 @@ externalData(
 snapshotDate(unique date snapshotDate : date ref);
 
 sourceLocationPrefix(varchar(900) prefix : string ref);
+
+/** Overlay support **/
+
+databaseMetadata(
+  string metadataKey: string ref,
+  string value: string ref
+);
+
+overlayChangedFiles(
+  string path: string ref
+);
 `)
 
 // Copied directly from the XML dbscheme
diff --git a/go/extractor/extractor.go b/go/extractor/extractor.go
index 67c127375847..5668d5894f85 100644
--- a/go/extractor/extractor.go
+++ b/go/extractor/extractor.go
@@ -58,16 +58,11 @@ func init() {
 	}
 }
 
-// Extract extracts the packages specified by the given patterns
-func Extract(patterns []string) error {
-	return ExtractWithFlags(nil, patterns, false)
-}
-
 // ExtractWithFlags extracts the packages specified by the given patterns and build flags
-func ExtractWithFlags(buildFlags []string, patterns []string, extractTests bool) error {
+func ExtractWithFlags(buildFlags []string, patterns []string, extractTests bool, sourceRoot string) error {
 	startTime := time.Now()
 
-	extraction := NewExtraction(buildFlags, patterns)
+	extraction := NewExtraction(buildFlags, patterns, sourceRoot)
 	defer extraction.StatWriter.Close()
 
 	modEnabled := os.Getenv("GO111MODULE") != "off"
@@ -323,16 +318,17 @@ func ExtractWithFlags(buildFlags []string, patterns []string, extractTests bool)
 type Extraction struct {
 	// A lock for preventing concurrent writes to maps and the stat trap writer, as they are not
 	// thread-safe
-	Lock         sync.Mutex
-	LabelKey     string
-	Label        trap.Label
-	StatWriter   *trap.Writer
-	WaitGroup    sync.WaitGroup
-	GoroutineSem *semaphore
-	FdSem        *semaphore
-	NextFileId   int
-	FileInfo     map[string]*FileInfo
-	SeenGoMods   map[string]bool
+	Lock           sync.Mutex
+	LabelKey       string
+	Label          trap.Label
+	StatWriter     *trap.Writer
+	WaitGroup      sync.WaitGroup
+	GoroutineSem   *semaphore
+	FdSem          *semaphore
+	NextFileId     int
+	FileInfo       map[string]*FileInfo
+	SeenGoMods     map[string]bool
+	OverlayChanges map[string]bool
 }
 
 type FileInfo struct {
@@ -367,7 +363,7 @@ func (extraction *Extraction) GetNextErr(path string) int {
 	return res
 }
 
-func NewExtraction(buildFlags []string, patterns []string) *Extraction {
+func NewExtraction(buildFlags []string, patterns []string, sourceRoot string) *Extraction {
 	hash := md5.New()
 	io.WriteString(hash, "go")
 	for _, buildFlag := range buildFlags {
@@ -379,6 +375,21 @@ func NewExtraction(buildFlags []string, patterns []string) *Extraction {
 	}
 	sum := hash.Sum(nil)
 
+	overlayChangeList := util.GetOverlayChanges(sourceRoot)
+	var overlayChanges map[string]bool
+	if overlayChangeList == nil {
+		overlayChanges = nil
+	} else {
+		overlayChanges = make(map[string]bool)
+		for _, changedFilePath := range overlayChangeList {
+			absPath, err := filepath.Abs(changedFilePath)
+			if err != nil {
+				log.Fatalf("Error resolving absolute path of overlay change %s: %s", changedFilePath, err.Error())
+			}
+			overlayChanges[absPath] = true
+		}
+	}
+
 	i := 0
 	var path string
 	// split compilation files into directories to avoid filling a single directory with too many files
@@ -438,10 +449,11 @@ func NewExtraction(buildFlags []string, patterns []string) *Extraction {
 		FdSem: newSemaphore(100),
 		// this semaphore is used to limit the number of goroutines spawned, so we
 		// don't run into memory issues
-		GoroutineSem: newSemaphore(MaxGoRoutines),
-		NextFileId:   0,
-		FileInfo:     make(map[string]*FileInfo),
-		SeenGoMods:   make(map[string]bool),
+		GoroutineSem:   newSemaphore(MaxGoRoutines),
+		NextFileId:     0,
+		FileInfo:       make(map[string]*FileInfo),
+		SeenGoMods:     make(map[string]bool),
+		OverlayChanges: overlayChanges,
 	}
 }
 
@@ -720,6 +732,15 @@ func (extraction *Extraction) extractFile(ast *ast.File, pkg *packages.Package)
 		return nil
 	}
 	path := normalizedPath(ast, fset)
+	// If we're extracting an overlay, we want to skip extraction of files that haven't changed.
+	// Since some files may be outside the source directory (e.g. files preprocessed by cgo) we
+	// can't easily know if they have changed (or came from source files that changed), so we always
+	// extract a file if it's not in the package directory.
+	if extraction.OverlayChanges != nil &&
+		!extraction.OverlayChanges[path] &&
+		strings.HasPrefix(path+string(filepath.Separator), pkg.Dir) {
+		return nil
+	}
 
 	extraction.FdSem.acquire(3)
 
@@ -791,12 +812,12 @@ func (extraction *Extraction) extractFileInfo(tw *trap.Writer, file string, isDu
 			displayPath = rawPath
 		}
 		if i == len(components)-1 {
-			lbl := tw.Labeler.FileLabelFor(file)
+			lbl := tw.Labeler.FileLabelFor(path)
 			dbscheme.FilesTable.Emit(tw, lbl, displayPath)
 			dbscheme.ContainerParentTable.Emit(tw, parentLbl, lbl)
 			dbscheme.HasLocationTable.Emit(tw, lbl, emitLocation(tw, lbl, 0, 0, 0, 0))
 			extraction.Lock.Lock()
-			slbl := extraction.StatWriter.Labeler.FileLabelFor(file)
+			slbl := extraction.StatWriter.Labeler.FileLabelFor(path)
 			if !isDummy {
 				dbscheme.CompilationCompilingFilesTable.Emit(extraction.StatWriter, extraction.Label, extraction.GetFileIdx(file), slbl)
 			}
diff --git a/go/extractor/gomodextractor.go b/go/extractor/gomodextractor.go
index be52af59760b..8dce96b6e6a7 100644
--- a/go/extractor/gomodextractor.go
+++ b/go/extractor/gomodextractor.go
@@ -20,6 +20,11 @@ func (extraction *Extraction) extractGoMod(path string) error {
 		path = normPath
 	}
 
+	if extraction.OverlayChanges != nil && !extraction.OverlayChanges[path] {
+		// This go.mod did not change since the base was extracted
+		return nil
+	}
+
 	extraction.Lock.Lock()
 	if extraction.SeenGoMods[path] {
 		extraction.Lock.Unlock()
diff --git a/go/extractor/srcarchive/BUILD.bazel b/go/extractor/srcarchive/BUILD.bazel
index e72e2e7ca08a..6d8776abce7b 100644
--- a/go/extractor/srcarchive/BUILD.bazel
+++ b/go/extractor/srcarchive/BUILD.bazel
@@ -10,6 +10,7 @@ go_library(
     ],
     importpath = "github.com/github/codeql-go/extractor/srcarchive",
     visibility = ["//visibility:public"],
+    deps = ["//go/extractor/util"],
 )
 
 go_test(
diff --git a/go/extractor/srcarchive/projectlayout.go b/go/extractor/srcarchive/projectlayout.go
index 6301755ef8ae..eecd0f379a4e 100644
--- a/go/extractor/srcarchive/projectlayout.go
+++ b/go/extractor/srcarchive/projectlayout.go
@@ -6,6 +6,8 @@ import (
 	"fmt"
 	"os"
 	"strings"
+
+	"github.com/github/codeql-go/extractor/util"
 )
 
 // ProjectLayout describes a very simple project layout rewriting paths starting
@@ -16,7 +18,7 @@ import (
 //	# to
 //	from//
 type ProjectLayout struct {
-	from, to string
+	From, To string
 }
 
 // normaliseSlashes adds an initial slash to `path` if there isn't one, and trims
@@ -28,6 +30,25 @@ func normaliseSlashes(path string) string {
 	return strings.TrimSuffix(path, "/")
 }
 
+// LoadProjectLayoutFromEnv loads a project layout from the file referenced by the
+// {CODEQL,SEMMLE}_PATH_TRANSFORMER environment variable. If neither env var is set, returns nil. If
+// the file cannot be read or does not have the right format, it returns an error.
+func LoadProjectLayoutFromEnv() (*ProjectLayout, error) {
+	pt := util.Getenv("CODEQL_PATH_TRANSFORMER", "SEMMLE_PATH_TRANSFORMER")
+	if pt == "" {
+		return nil, nil
+	}
+	ptf, err := os.Open(pt)
+	if err != nil {
+		return nil, err
+	}
+	pathTransformer, err = LoadProjectLayout(ptf)
+	if err != nil {
+		return nil, err
+	}
+	return pathTransformer, nil
+}
+
 // LoadProjectLayout loads a project layout from the given file, returning an error
 // if the file does not have the right format
 func LoadProjectLayout(file *os.File) (*ProjectLayout, error) {
@@ -41,7 +62,7 @@ func LoadProjectLayout(file *os.File) (*ProjectLayout, error) {
 	if !strings.HasPrefix(line, "#") {
 		return nil, fmt.Errorf("first line of project layout should start with #, but got %s", line)
 	}
-	res.to = normaliseSlashes(strings.TrimSpace(strings.TrimPrefix(line, "#")))
+	res.To = normaliseSlashes(strings.TrimSpace(strings.TrimPrefix(line, "#")))
 
 	if !scanner.Scan() {
 		return nil, errors.New("empty section in project-layout file")
@@ -57,7 +78,7 @@ func LoadProjectLayout(file *os.File) (*ProjectLayout, error) {
 	if strings.HasPrefix(line, "-") || strings.Contains(line, "*") || strings.Contains(line, "//") {
 		return nil, errors.New("unsupported project-layout feature")
 	}
-	res.from = normaliseSlashes(line)
+	res.From = normaliseSlashes(line)
 
 	for scanner.Scan() {
 		if strings.TrimSpace(scanner.Text()) != "" {
@@ -71,11 +92,11 @@ func LoadProjectLayout(file *os.File) (*ProjectLayout, error) {
 // transformString transforms `str` as specified by the project layout: if it starts with the `from`
 // prefix, that prefix is relaced by `to`; otherwise the string is returned unchanged
 func (p *ProjectLayout) transformString(str string) string {
-	if str == p.from {
-		return p.to
+	if str == p.From {
+		return p.To
 	}
-	if strings.HasPrefix(str, p.from+"/") {
-		return p.to + "/" + str[len(p.from)+1:]
+	if strings.HasPrefix(str, p.From+"/") {
+		return p.To + "/" + str[len(p.From)+1:]
 	}
 	return str
 }
diff --git a/go/extractor/srcarchive/srcarchive.go b/go/extractor/srcarchive/srcarchive.go
index ee9aea43064c..f871a2fbca2b 100644
--- a/go/extractor/srcarchive/srcarchive.go
+++ b/go/extractor/srcarchive/srcarchive.go
@@ -12,16 +12,11 @@ import (
 var pathTransformer *ProjectLayout
 
 func init() {
-	pt := os.Getenv("SEMMLE_PATH_TRANSFORMER")
-	if pt != "" {
-		ptf, err := os.Open(pt)
-		if err != nil {
-			log.Fatalf("Unable to open path transformer %s: %s.\n", pt, err.Error())
-		}
-		pathTransformer, err = LoadProjectLayout(ptf)
-		if err != nil {
-			log.Fatalf("Unable to initialize path transformer: %s.\n", err.Error())
-		}
+	pt, err := LoadProjectLayoutFromEnv()
+	if err == nil {
+		pathTransformer = pt
+	} else {
+		log.Fatalf("Unable to load path transformer: %s.\n", err.Error())
 	}
 }
 
@@ -69,7 +64,7 @@ func srcArchive() (string, error) {
 	return srcArchive, nil
 }
 
-// TransformPath applies the transformations specified by `SEMMLE_PATH_TRANSFORMER` (if any) to the
+// TransformPath applies the transformations specified by `CODEQL_PATH_TRANSFORMER` (if any) to the
 // given path
 func TransformPath(path string) string {
 	if pathTransformer != nil {
diff --git a/go/extractor/trap/labels.go b/go/extractor/trap/labels.go
index 2822da61ff14..9a03bfe9a57d 100644
--- a/go/extractor/trap/labels.go
+++ b/go/extractor/trap/labels.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"go/types"
 
+	"github.com/github/codeql-go/extractor/srcarchive"
 	"github.com/github/codeql-go/extractor/util"
 )
 
@@ -67,7 +68,7 @@ func (l *Labeler) GlobalID(key string) Label {
 // FileLabel returns the label for a file with path `path`.
 func (l *Labeler) FileLabel() Label {
 	if l.fileLabel == InvalidLabel {
-		l.fileLabel = l.FileLabelFor(l.tw.path)
+		l.fileLabel = l.FileLabelFor(srcarchive.TransformPath(l.tw.path))
 	}
 	return l.fileLabel
 }
diff --git a/go/extractor/util/BUILD.bazel b/go/extractor/util/BUILD.bazel
index b8f005378aa2..ee090607ced5 100644
--- a/go/extractor/util/BUILD.bazel
+++ b/go/extractor/util/BUILD.bazel
@@ -7,6 +7,7 @@ go_library(
     srcs = [
         "extractvendordirs.go",
         "logging.go",
+        "overlays.go",
         "registryproxy.go",
         "semver.go",
         "util.go",
diff --git a/go/extractor/util/overlays.go b/go/extractor/util/overlays.go
new file mode 100644
index 000000000000..6a5c3760549a
--- /dev/null
+++ b/go/extractor/util/overlays.go
@@ -0,0 +1,70 @@
+package util
+
+import (
+	"encoding/json"
+	"log"
+	"os"
+	"path/filepath"
+)
+
+func IsOverlayExtraction() bool {
+	_, present := os.LookupEnv("CODEQL_EXTRACTOR_GO_OVERLAY_METADATA_IN")
+	return present
+}
+
+// If the relevant environment variable is set, indicating that we are extracting an overlay
+// database, GetOverlayChanges returns the list of relative paths of files that have changed (or
+// been deleted). Otherwise, it returns `nil`.
+func GetOverlayChanges(sourceRoot string) []string {
+	if overlayChangesJsonPath, present := os.LookupEnv("CODEQL_EXTRACTOR_GO_OVERLAY_CHANGES"); present {
+		log.Printf("Reading overlay changes from: %s", overlayChangesJsonPath)
+
+		file, err := os.Open(overlayChangesJsonPath)
+		if err != nil {
+			log.Fatalf("Failed to open overlay changes JSON file: %s", err)
+		}
+		defer file.Close()
+
+		var overlayData struct {
+			Changes []string `json:"changes"`
+		}
+
+		decoder := json.NewDecoder(file)
+		if err := decoder.Decode(&overlayData); err != nil {
+			log.Fatalf("Failed to decode overlay changes JSON file: %s", err)
+		}
+
+		absPaths := make([]string, 0, len(overlayData.Changes))
+		if sourceRoot == "" {
+			// This shouldn't happen, because it implies the extractor was invoked in some way other
+			// than from the autobuilder. However, we'll only attempt to build an overlay if there
+			// exists an overlay _base_, and only the autobuilder writes the metadata file that
+			// ensures a database is created as an overlay-base.
+			log.Fatalf("Extractor is running in overlay mode, but --source-root was not provided")
+		}
+		for _, relPath := range overlayData.Changes {
+			absPaths = append(absPaths, filepath.Clean(sourceRoot+"/"+relPath))
+		}
+
+		return absPaths
+	} else {
+		return nil
+	}
+}
+
+// WriteOverlayBaseMetadata creates an empty metadata file if we are extracting an overlay base;
+// otherwise, it does nothing.
+func WriteOverlayBaseMetadata() {
+	if metadataPath, present := os.LookupEnv("CODEQL_EXTRACTOR_GO_OVERLAY_BASE_METADATA_OUT"); present {
+		log.Printf("Writing overlay base metadata to: %s", metadataPath)
+
+		// In principle, we could store some metadata here and read it back when extracting the
+		// overlay. For now, we don't need to store anything, but the CLI still requires us to write
+		// something, so just create an empty file.
+		file, err := os.Create(metadataPath)
+		if err != nil {
+			log.Fatalf("Failed to create overlay base metadata file: %s", err)
+		}
+		file.Close()
+	}
+}
diff --git a/go/ql/lib/go.dbscheme b/go/ql/lib/go.dbscheme
index b3da71c3ac20..b1341734d687 100644
--- a/go/ql/lib/go.dbscheme
+++ b/go/ql/lib/go.dbscheme
@@ -36,6 +36,17 @@ snapshotDate(unique date snapshotDate : date ref);
 
 sourceLocationPrefix(varchar(900) prefix : string ref);
 
+/** Overlay support **/
+
+databaseMetadata(
+  string metadataKey: string ref,
+  string value: string ref
+);
+
+overlayChangedFiles(
+  string path: string ref
+);
+
 
 /*
  * XML Files
diff --git a/go/ql/lib/qlpack.yml b/go/ql/lib/qlpack.yml
index 20ace6482e44..bb4ae36acc63 100644
--- a/go/ql/lib/qlpack.yml
+++ b/go/ql/lib/qlpack.yml
@@ -14,3 +14,4 @@ dependencies:
 dataExtensions:
   - ext/*.model.yml
 warnOnImplicitThis: true
+compileForOverlayEval: true
diff --git a/go/ql/lib/semmle/go/Locations.qll b/go/ql/lib/semmle/go/Locations.qll
index 817fea56f007..7503421c0ff2 100644
--- a/go/ql/lib/semmle/go/Locations.qll
+++ b/go/ql/lib/semmle/go/Locations.qll
@@ -1,6 +1,7 @@
 /** Provides classes for working with locations and program elements that have locations. */
 
 import go
+private import semmle.go.Overlay
 
 /**
  * A location as given by a file, a start line, a start column,
diff --git a/go/ql/lib/semmle/go/Overlay.qll b/go/ql/lib/semmle/go/Overlay.qll
new file mode 100644
index 000000000000..b7b1223878c6
--- /dev/null
+++ b/go/ql/lib/semmle/go/Overlay.qll
@@ -0,0 +1,52 @@
+/**
+ * Defines entity discard predicates for Go overlay analysis.
+ */
+overlay[local]
+module;
+
+/**
+ * A local predicate that always holds for the overlay variant and never holds for the base variant.
+ * This is used to define local predicates that behave differently for the base and overlay variant.
+ */
+private predicate isOverlay() { databaseMetadata("isOverlay", "true") }
+
+/** Gets the file containing the given `locatable`. */
+private @file getFile(@locatable locatable) {
+  exists(@location_default location | has_location(locatable, location) |
+    locations_default(location, result, _, _, _, _)
+  )
+}
+
+/** Holds if the `locatable` is in the `file` and is part of the overlay base database. */
+private predicate discardableLocatable(@file file, @locatable locatable) {
+  not isOverlay() and
+  file = getFile(locatable)
+}
+
+/**
+ * Holds if the given `path` is for a file in the base database whose entities should be discarded.
+ */
+bindingset[path]
+private predicate discardableFile(string path) {
+  isOverlay() and
+  (
+    overlayChangedFiles(path)
+    or
+    // The extractor unconditionally extracts files outside of the source directory (these are
+    // typically cgo-processed source files), so all entities in such files should be discarded.
+    not exists(string srcLoc | sourceLocationPrefix(srcLoc) |
+      path.substring(0, srcLoc.length()) = srcLoc
+    )
+  )
+}
+
+/**
+ * Holds if the given `locatable` should be discarded, because it is part of the overlay base and is
+ * in a file that was also extracted as part of the overlay database.
+ */
+overlay[discard_entity]
+private predicate discardLocatable(@locatable locatable) {
+  exists(@file file, string path | files(file, path) |
+    discardableLocatable(file, locatable) and discardableFile(path)
+  )
+}
diff --git a/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/go.dbscheme b/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/go.dbscheme
new file mode 100644
index 000000000000..b1341734d687
--- /dev/null
+++ b/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/go.dbscheme
@@ -0,0 +1,563 @@
+/** Auto-generated dbscheme; do not edit. Run `make gen` in directory `go/` to regenerate. */
+
+
+/** Duplicate code **/
+
+duplicateCode(
+  unique int id : @duplication,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+similarCode(
+  unique int id : @similarity,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+@duplication_or_similarity = @duplication | @similarity;
+
+tokens(
+  int id : @duplication_or_similarity ref,
+  int offset : int ref,
+  int beginLine : int ref,
+  int beginColumn : int ref,
+  int endLine : int ref,
+  int endColumn : int ref);
+
+/** External data **/
+
+externalData(
+  int id : @externalDataElement,
+  varchar(900) path : string ref,
+  int column: int ref,
+  varchar(900) value : string ref
+);
+
+snapshotDate(unique date snapshotDate : date ref);
+
+sourceLocationPrefix(varchar(900) prefix : string ref);
+
+/** Overlay support **/
+
+databaseMetadata(
+  string metadataKey: string ref,
+  string value: string ref
+);
+
+overlayChangedFiles(
+  string path: string ref
+);
+
+
+/*
+ * XML Files
+ */
+
+xmlEncoding(
+  unique int id: @file ref,
+  string encoding: string ref
+);
+
+xmlDTDs(
+  unique int id: @xmldtd,
+  string root: string ref,
+  string publicId: string ref,
+  string systemId: string ref,
+  int fileid: @file ref
+);
+
+xmlElements(
+  unique int id: @xmlelement,
+  string name: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int fileid: @file ref
+);
+
+xmlAttrs(
+  unique int id: @xmlattribute,
+  int elementid: @xmlelement ref,
+  string name: string ref,
+  string value: string ref,
+  int idx: int ref,
+  int fileid: @file ref
+);
+
+xmlNs(
+  int id: @xmlnamespace,
+  string prefixName: string ref,
+  string URI: string ref,
+  int fileid: @file ref
+);
+
+xmlHasNs(
+  int elementId: @xmlnamespaceable ref,
+  int nsId: @xmlnamespace ref,
+  int fileid: @file ref
+);
+
+xmlComments(
+  unique int id: @xmlcomment,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int fileid: @file ref
+);
+
+xmlChars(
+  unique int id: @xmlcharacters,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int isCDATA: int ref,
+  int fileid: @file ref
+);
+
+@xmlparent = @file | @xmlelement;
+@xmlnamespaceable = @xmlelement | @xmlattribute;
+
+xmllocations(
+  int xmlElement: @xmllocatable ref,
+  int location: @location_default ref
+);
+
+@xmllocatable = @xmlcharacters | @xmlelement | @xmlcomment | @xmlattribute | @xmldtd | @file | @xmlnamespace;
+
+compilations(unique int id: @compilation, string cwd: string ref);
+
+#keyset[id, num]
+compilation_args(int id: @compilation ref, int num: int ref, string arg: string ref);
+
+#keyset[id, num, kind]
+compilation_time(int id: @compilation ref, int num: int ref, int kind: int ref, float secs: float ref);
+
+diagnostic_for(unique int diagnostic: @diagnostic ref, int compilation: @compilation ref, int file_number: int ref, int file_number_diagnostic_number: int ref);
+
+compilation_finished(unique int id: @compilation ref, float cpu_seconds: float ref, float elapsed_seconds: float ref);
+
+#keyset[id, num]
+compilation_compiling_files(int id: @compilation ref, int num: int ref, int file: @file ref);
+
+diagnostics(unique int id: @diagnostic, int severity: int ref, string error_tag: string ref, string error_message: string ref,
+            string full_error_message: string ref, int location: @location ref);
+
+locations_default(unique int id: @location_default, int file: @file ref, int beginLine: int ref, int beginColumn: int ref,
+                  int endLine: int ref, int endColumn: int ref);
+
+numlines(int element_id: @sourceline ref, int num_lines: int ref, int num_code: int ref, int num_comment: int ref);
+
+files(unique int id: @file, string name: string ref);
+
+folders(unique int id: @folder, string name: string ref);
+
+containerparent(int parent: @container ref, unique int child: @container ref);
+
+has_location(unique int locatable: @locatable ref, int location: @location ref);
+
+#keyset[parent, idx]
+comment_groups(unique int id: @comment_group, int parent: @file ref, int idx: int ref);
+
+comments(unique int id: @comment, int kind: int ref, int parent: @comment_group ref, int idx: int ref, string text: string ref);
+
+doc_comments(unique int node: @documentable ref, int comment: @comment_group ref);
+
+#keyset[parent, idx]
+exprs(unique int id: @expr, int kind: int ref, int parent: @exprparent ref, int idx: int ref);
+
+literals(unique int expr: @expr ref, string value: string ref, string raw: string ref);
+
+constvalues(unique int expr: @expr ref, string value: string ref, string exact: string ref);
+
+fields(unique int id: @field, int parent: @fieldparent ref, int idx: int ref);
+
+typeparamdecls(unique int id: @typeparamdecl, int parent: @typeparamdeclparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+stmts(unique int id: @stmt, int kind: int ref, int parent: @stmtparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+decls(unique int id: @decl, int kind: int ref, int parent: @declparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+specs(unique int id: @spec, int kind: int ref, int parent: @gendecl ref, int idx: int ref);
+
+scopes(unique int id: @scope, int kind: int ref);
+
+scopenesting(unique int inner: @scope ref, int outer: @scope ref);
+
+scopenodes(unique int node: @scopenode ref, int scope: @localscope ref);
+
+objects(unique int id: @object, int kind: int ref, string name: string ref);
+
+objectscopes(unique int object: @object ref, int scope: @scope ref);
+
+objecttypes(unique int object: @object ref, int tp: @type ref);
+
+methodreceivers(unique int method: @object ref, int receiver: @object ref);
+
+fieldstructs(unique int field: @object ref, int struct: @structtype ref);
+
+methodhosts(int method: @object ref, int host: @definedtype ref);
+
+defs(int ident: @ident ref, int object: @object ref);
+
+uses(int ident: @ident ref, int object: @object ref);
+
+types(unique int id: @type, int kind: int ref);
+
+type_of(unique int expr: @expr ref, int tp: @type ref);
+
+typename(unique int tp: @type ref, string name: string ref);
+
+key_type(unique int map: @maptype ref, int tp: @type ref);
+
+element_type(unique int container: @containertype ref, int tp: @type ref);
+
+base_type(unique int ptr: @pointertype ref, int tp: @type ref);
+
+underlying_type(unique int defined: @definedtype ref, int tp: @type ref);
+
+#keyset[parent, index]
+component_types(int parent: @compositetype ref, int index: int ref, string name: string ref, int tp: @type ref);
+
+#keyset[parent, index]
+struct_tags(int parent: @structtype ref, int index: int ref, string tag: string ref);
+
+#keyset[interface, index]
+interface_private_method_ids(int interface: @interfacetype ref, int index: int ref, string id: string ref);
+
+array_length(unique int tp: @arraytype ref, string len: string ref);
+
+type_objects(unique int tp: @type ref, int object: @object ref);
+
+packages(unique int id: @package, string name: string ref, string path: string ref, int scope: @packagescope ref);
+
+#keyset[parent, idx]
+modexprs(unique int id: @modexpr, int kind: int ref, int parent: @modexprparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+modtokens(string token: string ref, int parent: @modexpr ref, int idx: int ref);
+
+#keyset[package, idx]
+errors(unique int id: @error, int kind: int ref, string msg: string ref, string rawpos: string ref,
+       string file: string ref, int line: int ref, int col: int ref, int package: @package ref, int idx: int ref);
+
+has_ellipsis(int id: @callorconversionexpr ref);
+
+variadic(int id: @signaturetype ref);
+
+#keyset[parent, idx]
+typeparam(unique int tp: @typeparamtype ref, string name: string ref, int bound: @compositetype ref,
+          int parent: @typeparamparentobject ref, int idx: int ref);
+
+@container = @file | @folder;
+
+@locatable = @xmllocatable | @node | @localscope;
+
+@node = @documentable | @exprparent | @modexprparent | @fieldparent | @stmtparent | @declparent | @typeparamdeclparent
+      | @scopenode | @comment_group | @comment;
+
+@documentable = @file | @field | @typeparamdecl | @spec | @gendecl | @funcdecl | @modexpr;
+
+@exprparent = @funcdef | @file | @expr | @field | @stmt | @decl | @typeparamdecl | @spec;
+
+@modexprparent = @file | @modexpr;
+
+@fieldparent = @decl | @structtypeexpr | @functypeexpr | @interfacetypeexpr;
+
+@stmtparent = @funcdef | @stmt | @decl;
+
+@declparent = @file | @declstmt;
+
+@typeparamdeclparent = @funcdecl | @typespec;
+
+@funcdef = @funclit | @funcdecl;
+
+@scopenode = @file | @functypeexpr | @blockstmt | @ifstmt | @caseclause | @switchstmt | @commclause | @loopstmt;
+
+@location = @location_default;
+
+@sourceline = @locatable;
+
+case @comment.kind of
+  0 = @slashslashcomment
+| 1 = @slashstarcomment;
+
+case @expr.kind of
+  0 = @badexpr
+| 1 = @ident
+| 2 = @ellipsis
+| 3 = @intlit
+| 4 = @floatlit
+| 5 = @imaglit
+| 6 = @charlit
+| 7 = @stringlit
+| 8 = @funclit
+| 9 = @compositelit
+| 10 = @parenexpr
+| 11 = @selectorexpr
+| 12 = @indexexpr
+| 13 = @genericfunctioninstantiationexpr
+| 14 = @generictypeinstantiationexpr
+| 15 = @sliceexpr
+| 16 = @typeassertexpr
+| 17 = @callorconversionexpr
+| 18 = @starexpr
+| 19 = @keyvalueexpr
+| 20 = @arraytypeexpr
+| 21 = @structtypeexpr
+| 22 = @functypeexpr
+| 23 = @interfacetypeexpr
+| 24 = @maptypeexpr
+| 25 = @typesetliteralexpr
+| 26 = @plusexpr
+| 27 = @minusexpr
+| 28 = @notexpr
+| 29 = @complementexpr
+| 30 = @derefexpr
+| 31 = @addressexpr
+| 32 = @arrowexpr
+| 33 = @lorexpr
+| 34 = @landexpr
+| 35 = @eqlexpr
+| 36 = @neqexpr
+| 37 = @lssexpr
+| 38 = @leqexpr
+| 39 = @gtrexpr
+| 40 = @geqexpr
+| 41 = @addexpr
+| 42 = @subexpr
+| 43 = @orexpr
+| 44 = @xorexpr
+| 45 = @mulexpr
+| 46 = @quoexpr
+| 47 = @remexpr
+| 48 = @shlexpr
+| 49 = @shrexpr
+| 50 = @andexpr
+| 51 = @andnotexpr
+| 52 = @sendchantypeexpr
+| 53 = @recvchantypeexpr
+| 54 = @sendrcvchantypeexpr;
+
+@basiclit = @intlit | @floatlit | @imaglit | @charlit | @stringlit;
+
+@operatorexpr = @logicalexpr | @arithmeticexpr | @bitwiseexpr | @unaryexpr | @binaryexpr;
+
+@logicalexpr = @logicalunaryexpr | @logicalbinaryexpr;
+
+@arithmeticexpr = @arithmeticunaryexpr | @arithmeticbinaryexpr;
+
+@bitwiseexpr = @bitwiseunaryexpr | @bitwisebinaryexpr;
+
+@unaryexpr = @logicalunaryexpr | @bitwiseunaryexpr | @arithmeticunaryexpr | @derefexpr | @addressexpr | @arrowexpr;
+
+@logicalunaryexpr = @notexpr;
+
+@bitwiseunaryexpr = @complementexpr;
+
+@arithmeticunaryexpr = @plusexpr | @minusexpr;
+
+@binaryexpr = @logicalbinaryexpr | @bitwisebinaryexpr | @arithmeticbinaryexpr | @comparison;
+
+@logicalbinaryexpr = @lorexpr | @landexpr;
+
+@bitwisebinaryexpr = @shiftexpr | @orexpr | @xorexpr | @andexpr | @andnotexpr;
+
+@arithmeticbinaryexpr = @addexpr | @subexpr | @mulexpr | @quoexpr | @remexpr;
+
+@shiftexpr = @shlexpr | @shrexpr;
+
+@comparison = @equalitytest | @relationalcomparison;
+
+@equalitytest = @eqlexpr | @neqexpr;
+
+@relationalcomparison = @lssexpr | @leqexpr | @gtrexpr | @geqexpr;
+
+@chantypeexpr = @sendchantypeexpr | @recvchantypeexpr | @sendrcvchantypeexpr;
+
+case @stmt.kind of
+  0 = @badstmt
+| 1 = @declstmt
+| 2 = @emptystmt
+| 3 = @labeledstmt
+| 4 = @exprstmt
+| 5 = @sendstmt
+| 6 = @incstmt
+| 7 = @decstmt
+| 8 = @gostmt
+| 9 = @deferstmt
+| 10 = @returnstmt
+| 11 = @breakstmt
+| 12 = @continuestmt
+| 13 = @gotostmt
+| 14 = @fallthroughstmt
+| 15 = @blockstmt
+| 16 = @ifstmt
+| 17 = @caseclause
+| 18 = @exprswitchstmt
+| 19 = @typeswitchstmt
+| 20 = @commclause
+| 21 = @selectstmt
+| 22 = @forstmt
+| 23 = @rangestmt
+| 24 = @assignstmt
+| 25 = @definestmt
+| 26 = @addassignstmt
+| 27 = @subassignstmt
+| 28 = @mulassignstmt
+| 29 = @quoassignstmt
+| 30 = @remassignstmt
+| 31 = @andassignstmt
+| 32 = @orassignstmt
+| 33 = @xorassignstmt
+| 34 = @shlassignstmt
+| 35 = @shrassignstmt
+| 36 = @andnotassignstmt;
+
+@incdecstmt = @incstmt | @decstmt;
+
+@assignment = @simpleassignstmt | @compoundassignstmt;
+
+@simpleassignstmt = @assignstmt | @definestmt;
+
+@compoundassignstmt = @addassignstmt | @subassignstmt | @mulassignstmt | @quoassignstmt | @remassignstmt
+                    | @andassignstmt | @orassignstmt | @xorassignstmt | @shlassignstmt | @shrassignstmt | @andnotassignstmt;
+
+@branchstmt = @breakstmt | @continuestmt | @gotostmt | @fallthroughstmt;
+
+@switchstmt = @exprswitchstmt | @typeswitchstmt;
+
+@loopstmt = @forstmt | @rangestmt;
+
+case @decl.kind of
+  0 = @baddecl
+| 1 = @importdecl
+| 2 = @constdecl
+| 3 = @typedecl
+| 4 = @vardecl
+| 5 = @funcdecl;
+
+@gendecl = @importdecl | @constdecl | @typedecl | @vardecl;
+
+case @spec.kind of
+  0 = @importspec
+| 1 = @valuespec
+| 2 = @typedefspec
+| 3 = @aliasspec;
+
+@typespec = @typedefspec | @aliasspec;
+
+case @object.kind of
+  0 = @pkgobject
+| 1 = @decltypeobject
+| 2 = @builtintypeobject
+| 3 = @declconstobject
+| 4 = @builtinconstobject
+| 5 = @declvarobject
+| 6 = @declfunctionobject
+| 7 = @builtinfunctionobject
+| 8 = @labelobject;
+
+@typeparamparentobject = @decltypeobject | @declfunctionobject;
+
+@declobject = @decltypeobject | @declconstobject | @declvarobject | @declfunctionobject;
+
+@builtinobject = @builtintypeobject | @builtinconstobject | @builtinfunctionobject;
+
+@typeobject = @decltypeobject | @builtintypeobject;
+
+@valueobject = @constobject | @varobject | @functionobject;
+
+@constobject = @declconstobject | @builtinconstobject;
+
+@varobject = @declvarobject;
+
+@functionobject = @declfunctionobject | @builtinfunctionobject;
+
+case @scope.kind of
+  0 = @universescope
+| 1 = @packagescope
+| 2 = @localscope;
+
+case @type.kind of
+  0 = @invalidtype
+| 1 = @boolexprtype
+| 2 = @inttype
+| 3 = @int8type
+| 4 = @int16type
+| 5 = @int32type
+| 6 = @int64type
+| 7 = @uinttype
+| 8 = @uint8type
+| 9 = @uint16type
+| 10 = @uint32type
+| 11 = @uint64type
+| 12 = @uintptrtype
+| 13 = @float32type
+| 14 = @float64type
+| 15 = @complex64type
+| 16 = @complex128type
+| 17 = @stringexprtype
+| 18 = @unsafepointertype
+| 19 = @boolliteraltype
+| 20 = @intliteraltype
+| 21 = @runeliteraltype
+| 22 = @floatliteraltype
+| 23 = @complexliteraltype
+| 24 = @stringliteraltype
+| 25 = @nilliteraltype
+| 26 = @typeparamtype
+| 27 = @arraytype
+| 28 = @slicetype
+| 29 = @structtype
+| 30 = @pointertype
+| 31 = @interfacetype
+| 32 = @tupletype
+| 33 = @signaturetype
+| 34 = @maptype
+| 35 = @sendchantype
+| 36 = @recvchantype
+| 37 = @sendrcvchantype
+| 38 = @definedtype
+| 39 = @typesetliteraltype;
+
+@basictype = @booltype | @numerictype | @stringtype | @literaltype | @invalidtype | @unsafepointertype;
+
+@booltype = @boolexprtype | @boolliteraltype;
+
+@numerictype = @integertype | @floattype | @complextype;
+
+@integertype = @signedintegertype | @unsignedintegertype;
+
+@signedintegertype = @inttype | @int8type | @int16type | @int32type | @int64type | @intliteraltype | @runeliteraltype;
+
+@unsignedintegertype = @uinttype | @uint8type | @uint16type | @uint32type | @uint64type | @uintptrtype;
+
+@floattype = @float32type | @float64type | @floatliteraltype;
+
+@complextype = @complex64type | @complex128type | @complexliteraltype;
+
+@stringtype = @stringexprtype | @stringliteraltype;
+
+@literaltype = @boolliteraltype | @intliteraltype | @runeliteraltype | @floatliteraltype | @complexliteraltype
+             | @stringliteraltype | @nilliteraltype;
+
+@compositetype = @typeparamtype | @containertype | @structtype | @pointertype | @interfacetype | @tupletype
+               | @signaturetype | @definedtype | @typesetliteraltype;
+
+@containertype = @arraytype | @slicetype | @maptype | @chantype;
+
+@chantype = @sendchantype | @recvchantype | @sendrcvchantype;
+
+case @modexpr.kind of
+  0 = @modcommentblock
+| 1 = @modline
+| 2 = @modlineblock
+| 3 = @modlparen
+| 4 = @modrparen;
+
+case @error.kind of
+  0 = @unknownerror
+| 1 = @listerror
+| 2 = @parseerror
+| 3 = @typeerror;
+
diff --git a/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/old.dbscheme b/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/old.dbscheme
new file mode 100644
index 000000000000..b3da71c3ac20
--- /dev/null
+++ b/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/old.dbscheme
@@ -0,0 +1,552 @@
+/** Auto-generated dbscheme; do not edit. Run `make gen` in directory `go/` to regenerate. */
+
+
+/** Duplicate code **/
+
+duplicateCode(
+  unique int id : @duplication,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+similarCode(
+  unique int id : @similarity,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+@duplication_or_similarity = @duplication | @similarity;
+
+tokens(
+  int id : @duplication_or_similarity ref,
+  int offset : int ref,
+  int beginLine : int ref,
+  int beginColumn : int ref,
+  int endLine : int ref,
+  int endColumn : int ref);
+
+/** External data **/
+
+externalData(
+  int id : @externalDataElement,
+  varchar(900) path : string ref,
+  int column: int ref,
+  varchar(900) value : string ref
+);
+
+snapshotDate(unique date snapshotDate : date ref);
+
+sourceLocationPrefix(varchar(900) prefix : string ref);
+
+
+/*
+ * XML Files
+ */
+
+xmlEncoding(
+  unique int id: @file ref,
+  string encoding: string ref
+);
+
+xmlDTDs(
+  unique int id: @xmldtd,
+  string root: string ref,
+  string publicId: string ref,
+  string systemId: string ref,
+  int fileid: @file ref
+);
+
+xmlElements(
+  unique int id: @xmlelement,
+  string name: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int fileid: @file ref
+);
+
+xmlAttrs(
+  unique int id: @xmlattribute,
+  int elementid: @xmlelement ref,
+  string name: string ref,
+  string value: string ref,
+  int idx: int ref,
+  int fileid: @file ref
+);
+
+xmlNs(
+  int id: @xmlnamespace,
+  string prefixName: string ref,
+  string URI: string ref,
+  int fileid: @file ref
+);
+
+xmlHasNs(
+  int elementId: @xmlnamespaceable ref,
+  int nsId: @xmlnamespace ref,
+  int fileid: @file ref
+);
+
+xmlComments(
+  unique int id: @xmlcomment,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int fileid: @file ref
+);
+
+xmlChars(
+  unique int id: @xmlcharacters,
+  string text: string ref,
+  int parentid: @xmlparent ref,
+  int idx: int ref,
+  int isCDATA: int ref,
+  int fileid: @file ref
+);
+
+@xmlparent = @file | @xmlelement;
+@xmlnamespaceable = @xmlelement | @xmlattribute;
+
+xmllocations(
+  int xmlElement: @xmllocatable ref,
+  int location: @location_default ref
+);
+
+@xmllocatable = @xmlcharacters | @xmlelement | @xmlcomment | @xmlattribute | @xmldtd | @file | @xmlnamespace;
+
+compilations(unique int id: @compilation, string cwd: string ref);
+
+#keyset[id, num]
+compilation_args(int id: @compilation ref, int num: int ref, string arg: string ref);
+
+#keyset[id, num, kind]
+compilation_time(int id: @compilation ref, int num: int ref, int kind: int ref, float secs: float ref);
+
+diagnostic_for(unique int diagnostic: @diagnostic ref, int compilation: @compilation ref, int file_number: int ref, int file_number_diagnostic_number: int ref);
+
+compilation_finished(unique int id: @compilation ref, float cpu_seconds: float ref, float elapsed_seconds: float ref);
+
+#keyset[id, num]
+compilation_compiling_files(int id: @compilation ref, int num: int ref, int file: @file ref);
+
+diagnostics(unique int id: @diagnostic, int severity: int ref, string error_tag: string ref, string error_message: string ref,
+            string full_error_message: string ref, int location: @location ref);
+
+locations_default(unique int id: @location_default, int file: @file ref, int beginLine: int ref, int beginColumn: int ref,
+                  int endLine: int ref, int endColumn: int ref);
+
+numlines(int element_id: @sourceline ref, int num_lines: int ref, int num_code: int ref, int num_comment: int ref);
+
+files(unique int id: @file, string name: string ref);
+
+folders(unique int id: @folder, string name: string ref);
+
+containerparent(int parent: @container ref, unique int child: @container ref);
+
+has_location(unique int locatable: @locatable ref, int location: @location ref);
+
+#keyset[parent, idx]
+comment_groups(unique int id: @comment_group, int parent: @file ref, int idx: int ref);
+
+comments(unique int id: @comment, int kind: int ref, int parent: @comment_group ref, int idx: int ref, string text: string ref);
+
+doc_comments(unique int node: @documentable ref, int comment: @comment_group ref);
+
+#keyset[parent, idx]
+exprs(unique int id: @expr, int kind: int ref, int parent: @exprparent ref, int idx: int ref);
+
+literals(unique int expr: @expr ref, string value: string ref, string raw: string ref);
+
+constvalues(unique int expr: @expr ref, string value: string ref, string exact: string ref);
+
+fields(unique int id: @field, int parent: @fieldparent ref, int idx: int ref);
+
+typeparamdecls(unique int id: @typeparamdecl, int parent: @typeparamdeclparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+stmts(unique int id: @stmt, int kind: int ref, int parent: @stmtparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+decls(unique int id: @decl, int kind: int ref, int parent: @declparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+specs(unique int id: @spec, int kind: int ref, int parent: @gendecl ref, int idx: int ref);
+
+scopes(unique int id: @scope, int kind: int ref);
+
+scopenesting(unique int inner: @scope ref, int outer: @scope ref);
+
+scopenodes(unique int node: @scopenode ref, int scope: @localscope ref);
+
+objects(unique int id: @object, int kind: int ref, string name: string ref);
+
+objectscopes(unique int object: @object ref, int scope: @scope ref);
+
+objecttypes(unique int object: @object ref, int tp: @type ref);
+
+methodreceivers(unique int method: @object ref, int receiver: @object ref);
+
+fieldstructs(unique int field: @object ref, int struct: @structtype ref);
+
+methodhosts(int method: @object ref, int host: @definedtype ref);
+
+defs(int ident: @ident ref, int object: @object ref);
+
+uses(int ident: @ident ref, int object: @object ref);
+
+types(unique int id: @type, int kind: int ref);
+
+type_of(unique int expr: @expr ref, int tp: @type ref);
+
+typename(unique int tp: @type ref, string name: string ref);
+
+key_type(unique int map: @maptype ref, int tp: @type ref);
+
+element_type(unique int container: @containertype ref, int tp: @type ref);
+
+base_type(unique int ptr: @pointertype ref, int tp: @type ref);
+
+underlying_type(unique int defined: @definedtype ref, int tp: @type ref);
+
+#keyset[parent, index]
+component_types(int parent: @compositetype ref, int index: int ref, string name: string ref, int tp: @type ref);
+
+#keyset[parent, index]
+struct_tags(int parent: @structtype ref, int index: int ref, string tag: string ref);
+
+#keyset[interface, index]
+interface_private_method_ids(int interface: @interfacetype ref, int index: int ref, string id: string ref);
+
+array_length(unique int tp: @arraytype ref, string len: string ref);
+
+type_objects(unique int tp: @type ref, int object: @object ref);
+
+packages(unique int id: @package, string name: string ref, string path: string ref, int scope: @packagescope ref);
+
+#keyset[parent, idx]
+modexprs(unique int id: @modexpr, int kind: int ref, int parent: @modexprparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+modtokens(string token: string ref, int parent: @modexpr ref, int idx: int ref);
+
+#keyset[package, idx]
+errors(unique int id: @error, int kind: int ref, string msg: string ref, string rawpos: string ref,
+       string file: string ref, int line: int ref, int col: int ref, int package: @package ref, int idx: int ref);
+
+has_ellipsis(int id: @callorconversionexpr ref);
+
+variadic(int id: @signaturetype ref);
+
+#keyset[parent, idx]
+typeparam(unique int tp: @typeparamtype ref, string name: string ref, int bound: @compositetype ref,
+          int parent: @typeparamparentobject ref, int idx: int ref);
+
+@container = @file | @folder;
+
+@locatable = @xmllocatable | @node | @localscope;
+
+@node = @documentable | @exprparent | @modexprparent | @fieldparent | @stmtparent | @declparent | @typeparamdeclparent
+      | @scopenode | @comment_group | @comment;
+
+@documentable = @file | @field | @typeparamdecl | @spec | @gendecl | @funcdecl | @modexpr;
+
+@exprparent = @funcdef | @file | @expr | @field | @stmt | @decl | @typeparamdecl | @spec;
+
+@modexprparent = @file | @modexpr;
+
+@fieldparent = @decl | @structtypeexpr | @functypeexpr | @interfacetypeexpr;
+
+@stmtparent = @funcdef | @stmt | @decl;
+
+@declparent = @file | @declstmt;
+
+@typeparamdeclparent = @funcdecl | @typespec;
+
+@funcdef = @funclit | @funcdecl;
+
+@scopenode = @file | @functypeexpr | @blockstmt | @ifstmt | @caseclause | @switchstmt | @commclause | @loopstmt;
+
+@location = @location_default;
+
+@sourceline = @locatable;
+
+case @comment.kind of
+  0 = @slashslashcomment
+| 1 = @slashstarcomment;
+
+case @expr.kind of
+  0 = @badexpr
+| 1 = @ident
+| 2 = @ellipsis
+| 3 = @intlit
+| 4 = @floatlit
+| 5 = @imaglit
+| 6 = @charlit
+| 7 = @stringlit
+| 8 = @funclit
+| 9 = @compositelit
+| 10 = @parenexpr
+| 11 = @selectorexpr
+| 12 = @indexexpr
+| 13 = @genericfunctioninstantiationexpr
+| 14 = @generictypeinstantiationexpr
+| 15 = @sliceexpr
+| 16 = @typeassertexpr
+| 17 = @callorconversionexpr
+| 18 = @starexpr
+| 19 = @keyvalueexpr
+| 20 = @arraytypeexpr
+| 21 = @structtypeexpr
+| 22 = @functypeexpr
+| 23 = @interfacetypeexpr
+| 24 = @maptypeexpr
+| 25 = @typesetliteralexpr
+| 26 = @plusexpr
+| 27 = @minusexpr
+| 28 = @notexpr
+| 29 = @complementexpr
+| 30 = @derefexpr
+| 31 = @addressexpr
+| 32 = @arrowexpr
+| 33 = @lorexpr
+| 34 = @landexpr
+| 35 = @eqlexpr
+| 36 = @neqexpr
+| 37 = @lssexpr
+| 38 = @leqexpr
+| 39 = @gtrexpr
+| 40 = @geqexpr
+| 41 = @addexpr
+| 42 = @subexpr
+| 43 = @orexpr
+| 44 = @xorexpr
+| 45 = @mulexpr
+| 46 = @quoexpr
+| 47 = @remexpr
+| 48 = @shlexpr
+| 49 = @shrexpr
+| 50 = @andexpr
+| 51 = @andnotexpr
+| 52 = @sendchantypeexpr
+| 53 = @recvchantypeexpr
+| 54 = @sendrcvchantypeexpr;
+
+@basiclit = @intlit | @floatlit | @imaglit | @charlit | @stringlit;
+
+@operatorexpr = @logicalexpr | @arithmeticexpr | @bitwiseexpr | @unaryexpr | @binaryexpr;
+
+@logicalexpr = @logicalunaryexpr | @logicalbinaryexpr;
+
+@arithmeticexpr = @arithmeticunaryexpr | @arithmeticbinaryexpr;
+
+@bitwiseexpr = @bitwiseunaryexpr | @bitwisebinaryexpr;
+
+@unaryexpr = @logicalunaryexpr | @bitwiseunaryexpr | @arithmeticunaryexpr | @derefexpr | @addressexpr | @arrowexpr;
+
+@logicalunaryexpr = @notexpr;
+
+@bitwiseunaryexpr = @complementexpr;
+
+@arithmeticunaryexpr = @plusexpr | @minusexpr;
+
+@binaryexpr = @logicalbinaryexpr | @bitwisebinaryexpr | @arithmeticbinaryexpr | @comparison;
+
+@logicalbinaryexpr = @lorexpr | @landexpr;
+
+@bitwisebinaryexpr = @shiftexpr | @orexpr | @xorexpr | @andexpr | @andnotexpr;
+
+@arithmeticbinaryexpr = @addexpr | @subexpr | @mulexpr | @quoexpr | @remexpr;
+
+@shiftexpr = @shlexpr | @shrexpr;
+
+@comparison = @equalitytest | @relationalcomparison;
+
+@equalitytest = @eqlexpr | @neqexpr;
+
+@relationalcomparison = @lssexpr | @leqexpr | @gtrexpr | @geqexpr;
+
+@chantypeexpr = @sendchantypeexpr | @recvchantypeexpr | @sendrcvchantypeexpr;
+
+case @stmt.kind of
+  0 = @badstmt
+| 1 = @declstmt
+| 2 = @emptystmt
+| 3 = @labeledstmt
+| 4 = @exprstmt
+| 5 = @sendstmt
+| 6 = @incstmt
+| 7 = @decstmt
+| 8 = @gostmt
+| 9 = @deferstmt
+| 10 = @returnstmt
+| 11 = @breakstmt
+| 12 = @continuestmt
+| 13 = @gotostmt
+| 14 = @fallthroughstmt
+| 15 = @blockstmt
+| 16 = @ifstmt
+| 17 = @caseclause
+| 18 = @exprswitchstmt
+| 19 = @typeswitchstmt
+| 20 = @commclause
+| 21 = @selectstmt
+| 22 = @forstmt
+| 23 = @rangestmt
+| 24 = @assignstmt
+| 25 = @definestmt
+| 26 = @addassignstmt
+| 27 = @subassignstmt
+| 28 = @mulassignstmt
+| 29 = @quoassignstmt
+| 30 = @remassignstmt
+| 31 = @andassignstmt
+| 32 = @orassignstmt
+| 33 = @xorassignstmt
+| 34 = @shlassignstmt
+| 35 = @shrassignstmt
+| 36 = @andnotassignstmt;
+
+@incdecstmt = @incstmt | @decstmt;
+
+@assignment = @simpleassignstmt | @compoundassignstmt;
+
+@simpleassignstmt = @assignstmt | @definestmt;
+
+@compoundassignstmt = @addassignstmt | @subassignstmt | @mulassignstmt | @quoassignstmt | @remassignstmt
+                    | @andassignstmt | @orassignstmt | @xorassignstmt | @shlassignstmt | @shrassignstmt | @andnotassignstmt;
+
+@branchstmt = @breakstmt | @continuestmt | @gotostmt | @fallthroughstmt;
+
+@switchstmt = @exprswitchstmt | @typeswitchstmt;
+
+@loopstmt = @forstmt | @rangestmt;
+
+case @decl.kind of
+  0 = @baddecl
+| 1 = @importdecl
+| 2 = @constdecl
+| 3 = @typedecl
+| 4 = @vardecl
+| 5 = @funcdecl;
+
+@gendecl = @importdecl | @constdecl | @typedecl | @vardecl;
+
+case @spec.kind of
+  0 = @importspec
+| 1 = @valuespec
+| 2 = @typedefspec
+| 3 = @aliasspec;
+
+@typespec = @typedefspec | @aliasspec;
+
+case @object.kind of
+  0 = @pkgobject
+| 1 = @decltypeobject
+| 2 = @builtintypeobject
+| 3 = @declconstobject
+| 4 = @builtinconstobject
+| 5 = @declvarobject
+| 6 = @declfunctionobject
+| 7 = @builtinfunctionobject
+| 8 = @labelobject;
+
+@typeparamparentobject = @decltypeobject | @declfunctionobject;
+
+@declobject = @decltypeobject | @declconstobject | @declvarobject | @declfunctionobject;
+
+@builtinobject = @builtintypeobject | @builtinconstobject | @builtinfunctionobject;
+
+@typeobject = @decltypeobject | @builtintypeobject;
+
+@valueobject = @constobject | @varobject | @functionobject;
+
+@constobject = @declconstobject | @builtinconstobject;
+
+@varobject = @declvarobject;
+
+@functionobject = @declfunctionobject | @builtinfunctionobject;
+
+case @scope.kind of
+  0 = @universescope
+| 1 = @packagescope
+| 2 = @localscope;
+
+case @type.kind of
+  0 = @invalidtype
+| 1 = @boolexprtype
+| 2 = @inttype
+| 3 = @int8type
+| 4 = @int16type
+| 5 = @int32type
+| 6 = @int64type
+| 7 = @uinttype
+| 8 = @uint8type
+| 9 = @uint16type
+| 10 = @uint32type
+| 11 = @uint64type
+| 12 = @uintptrtype
+| 13 = @float32type
+| 14 = @float64type
+| 15 = @complex64type
+| 16 = @complex128type
+| 17 = @stringexprtype
+| 18 = @unsafepointertype
+| 19 = @boolliteraltype
+| 20 = @intliteraltype
+| 21 = @runeliteraltype
+| 22 = @floatliteraltype
+| 23 = @complexliteraltype
+| 24 = @stringliteraltype
+| 25 = @nilliteraltype
+| 26 = @typeparamtype
+| 27 = @arraytype
+| 28 = @slicetype
+| 29 = @structtype
+| 30 = @pointertype
+| 31 = @interfacetype
+| 32 = @tupletype
+| 33 = @signaturetype
+| 34 = @maptype
+| 35 = @sendchantype
+| 36 = @recvchantype
+| 37 = @sendrcvchantype
+| 38 = @definedtype
+| 39 = @typesetliteraltype;
+
+@basictype = @booltype | @numerictype | @stringtype | @literaltype | @invalidtype | @unsafepointertype;
+
+@booltype = @boolexprtype | @boolliteraltype;
+
+@numerictype = @integertype | @floattype | @complextype;
+
+@integertype = @signedintegertype | @unsignedintegertype;
+
+@signedintegertype = @inttype | @int8type | @int16type | @int32type | @int64type | @intliteraltype | @runeliteraltype;
+
+@unsignedintegertype = @uinttype | @uint8type | @uint16type | @uint32type | @uint64type | @uintptrtype;
+
+@floattype = @float32type | @float64type | @floatliteraltype;
+
+@complextype = @complex64type | @complex128type | @complexliteraltype;
+
+@stringtype = @stringexprtype | @stringliteraltype;
+
+@literaltype = @boolliteraltype | @intliteraltype | @runeliteraltype | @floatliteraltype | @complexliteraltype
+             | @stringliteraltype | @nilliteraltype;
+
+@compositetype = @typeparamtype | @containertype | @structtype | @pointertype | @interfacetype | @tupletype
+               | @signaturetype | @definedtype | @typesetliteraltype;
+
+@containertype = @arraytype | @slicetype | @maptype | @chantype;
+
+@chantype = @sendchantype | @recvchantype | @sendrcvchantype;
+
+case @modexpr.kind of
+  0 = @modcommentblock
+| 1 = @modline
+| 2 = @modlineblock
+| 3 = @modlparen
+| 4 = @modrparen;
+
+case @error.kind of
+  0 = @unknownerror
+| 1 = @listerror
+| 2 = @parseerror
+| 3 = @typeerror;
+
diff --git a/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/upgrade.properties b/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/upgrade.properties
new file mode 100644
index 000000000000..52b67d65af75
--- /dev/null
+++ b/go/ql/lib/upgrades/b3da71c3ac204b557c86e9d9c26012360bdbdccb/upgrade.properties
@@ -0,0 +1,2 @@
+description: Add databaseMetadata and overlayChangedFiles relations
+compatibility: full