diff --git a/db/docs/protected_branch_merge_access_levels.yml b/db/docs/protected_branch_merge_access_levels.yml
index a16ddd6aba0207e9c92307394c68407e9c1c78eb..2ab9e7793497c087c1ea899b4ff98f76decf60c4 100644
--- a/db/docs/protected_branch_merge_access_levels.yml
+++ b/db/docs/protected_branch_merge_access_levels.yml
@@ -8,4 +8,22 @@ description: Stores merge access settings for protected branches
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab-foss/-/merge_requests/5081
 milestone: '8.11'
 gitlab_schema: gitlab_main_cell
-sharding_key_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/490485
+allow_cross_foreign_keys:
+- gitlab_main_clusterwide
+desired_sharding_key:
+  protected_branch_project_id:
+    references: projects
+    backfill_via:
+      parent:
+        foreign_key: protected_branch_id
+        table: protected_branches
+        sharding_key: project_id
+        belongs_to: protected_branch
+  protected_branch_namespace_id:
+    references: namespaces
+    backfill_via:
+      parent:
+        foreign_key: protected_branch_id
+        table: protected_branches
+        sharding_key: namespace_id
+        belongs_to: protected_branch