migrations: add index to paths.module_id

Change-Id: I9f3f4cc76988dd2107988c1e42f47f7c9c70a8f1
Reviewed-on: https://team-review.git.corp.google.com/c/golang/discovery/+/720341
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/migrations/000014_add_paths_module_id_index.down.sql b/migrations/000014_add_paths_module_id_index.down.sql
new file mode 100644
index 0000000..c736cde
--- /dev/null
+++ b/migrations/000014_add_paths_module_id_index.down.sql
@@ -0,0 +1,9 @@
+-- Copyright 2020 The Go Authors. All rights reserved.
+-- Use of this source code is governed by a BSD-style
+-- license that can be found in the LICENSE file.
+
+BEGIN;
+
+DROP INDEX idx_paths_module_id;
+
+END;
diff --git a/migrations/000014_add_paths_module_id_index.up.sql b/migrations/000014_add_paths_module_id_index.up.sql
new file mode 100644
index 0000000..a514072
--- /dev/null
+++ b/migrations/000014_add_paths_module_id_index.up.sql
@@ -0,0 +1,9 @@
+-- Copyright 2020 The Go Authors. All rights reserved.
+-- Use of this source code is governed by a BSD-style
+-- license that can be found in the LICENSE file.
+
+BEGIN;
+
+CREATE INDEX idx_paths_module_id ON paths(module_id);
+
+END;