diff --git a/internal/db/schema/migrations/oss/postgres/91/03_indexes_grants_query.up.sql b/internal/db/schema/migrations/oss/postgres/91/03_indexes_grants_query.up.sql
new file mode 100644
index 0000000000..97c779dbdd
--- /dev/null
+++ b/internal/db/schema/migrations/oss/postgres/91/03_indexes_grants_query.up.sql
@@ -0,0 +1,39 @@
+-- Copyright (c) HashiCorp, Inc.
+-- SPDX-License-Identifier: BUSL-1.1
+
+begin;
+  -- For each of these tables, swap the ordering of the
+  -- columns in the index for the primary key.
+  -- This helps the grants query that contains
+  -- several where clauses on what is currently the second
+  -- column in these indexes. By swapping the order, this
+  -- will make it more likely that the query planner will
+  -- choose to use the index.
+  -- See: https://www.postgresql.org/docs/current/indexes-multicolumn.html
+
+      alter table auth_oidc_managed_group_member_account
+  drop constraint auth_oidc_managed_group_member_account_pkey,
+  add primary key (member_id, managed_group_id);
+
+      alter table iam_managed_group_role
+  drop constraint iam_managed_group_role_pkey,
+  add primary key (principal_id, role_id);
+
+      alter table iam_group_member_user
+  drop constraint iam_group_member_user_pkey,
+  add primary key (member_id, group_id);
+
+      alter table iam_group_role
+  drop constraint iam_group_role_pkey,
+  add primary key (principal_id, role_id);
+
+      alter table iam_user_role
+  drop constraint iam_user_role_pkey,
+  add primary key (principal_id, role_id);
+
+  analyze auth_oidc_managed_group_member_account,
+          iam_managed_group_role,
+          iam_group_member_user,
+          iam_group_role,
+          iam_user_role;
+commit;