Imrpove migrations

db/migrations/003_create_memberships.rb

@@ -5,7 +5,8 @@ Sequel.migration do
 
       foreign_key :member_id, :members,
         type: :Bignum,
-        null: false
+        null: false,
+        on_delete: :cascade
 
       String :status, null: false, default: "pending"
 
@@ -16,13 +17,18 @@ Sequel.migration do
       DateTime :decided_at
 
       foreign_key :recorded_by, :members,
-        type: :Bignum
+        type: :Bignum,
+        null: true,
+        on_delete: :set_null
 
+      index :member_id, name: :memberships_member_id_all_index
+      index :recorded_by
       index :status
 
       # Un seul dossier en attente ou une seule adhésion acceptée.
       index :member_id,
         unique: true,
+        name: :memberships_active_member_id_index,
         where: { status: ["pending", "accepted"] }
 
       constraint :memberships_status_valid,