diff --git a/schema/01_initial.sql b/schema/01_initial.sql
index 94409c0..ab3c6f2 100644
--- a/schema/01_initial.sql
+++ b/schema/01_initial.sql
@@ -20,19 +20,31 @@ create table if not exists pools(
   primary key(layer3domain_id, id)
 );
 
-create table if not exists containers(
-  layer3domain_id integer not null references layer3domains(id),
-  network cidr not null,
-  pool_id integer,
+create table containers(
+	layer3domain_id integer not null references layer3domains(id),
+ 	subnet cidr not null,
+ 	pool_id integer,
+  attributes jsonb not null default '{}'::jsonb,
   created_at timestamptz not null default now(),
   created_by varchar(128) not null,
   modified_at timestamptz not null default now(),
   modified_by varchar(128) not null,
-  attributes jsonb not null default '{}'::jsonb,
-  unique(layer3domain_id, network),
-  foreign key (layer3domain_id, pool_id) references pools(layer3domain_id, id)
+ 	unique(layer3domain_id, subnet),
+	foreign key (layer3domain_id, pool_id) references pools(layer3domain_id, id)
 );
-create index if not exists container_reference_key on containers(layer3domain_id, pool_id, network);
+
+create or replace view containers_tree as
+select
+	c.layer3domain_id,
+  c.subnet,
+  array_agg(p.subnet order by p.subnet) filter (where p.subnet is not null) as parents
+from containers c
+left join containers p
+  on c.subnet << p.subnet
+  and c.layer3domain_id = p.layer3domain_id
+group by c.layer3domain_id, c.subnet
+order by c.layer3domain_id, c.subnet;
+comment on view containers_tree is 'This returns a tree of all containers so that sub trees can be shown.';
 
 create table if not exists ips(
   layer3domain_id integer not null,