From 8fdcb8defa4708c82146a3915ca7d75fa7b8b2f8 Mon Sep 17 00:00:00 2001
From: Tom Russell <tomalrussell@gmail.com>
Date: Sun, 30 Sep 2018 16:17:11 +0100
Subject: [PATCH] Add building_properties table, buildings.revision_id

---
 migrations/001.core.down.sql            |  2 ++
 migrations/001.core.up.sql              | 30 +++++++++++++++++++------
 migrations/003.index-buildings.down.sql |  3 +++
 migrations/003.index-buildings.up.sql   | 10 +++++++--
 4 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/migrations/001.core.down.sql b/migrations/001.core.down.sql
index 476a9482..b29b9925 100644
--- a/migrations/001.core.down.sql
+++ b/migrations/001.core.down.sql
@@ -1,8 +1,10 @@
 -- Drop all tables
+ALTER TABLE buildings DROP COLUMN IF EXISTS revision_id;
 DROP TABLE IF EXISTS logs;
 DROP TABLE IF EXISTS users;
 DROP TABLE IF EXISTS user_sessions;
 DROP TABLE IF EXISTS user_categories;
 DROP TABLE IF EXISTS user_access_levels;
+DROP TABLE IF EXISTS building_properties;
 DROP TABLE IF EXISTS buildings;
 DROP TABLE IF EXISTS geometries;
diff --git a/migrations/001.core.up.sql b/migrations/001.core.up.sql
index 45e5f724..a997eebe 100644
--- a/migrations/001.core.up.sql
+++ b/migrations/001.core.up.sql
@@ -20,19 +20,33 @@ CREATE TABLE IF NOT EXISTS geometries (
 CREATE TABLE IF NOT EXISTS buildings (
     -- internal unique id
     building_id serial PRIMARY KEY,
-    -- unique property reference number
-    ref_uprn bigint,
     -- OS MasterMap topo id
     ref_toid varchar,
     -- OSM reference id
     ref_osm_id bigint,
-    -- jsonb document for all data, attributes to be specified in application
-    building_doc jsonb,
     -- reference to geometry, aiming to decouple from geometry provider
     geometry_id integer REFERENCES geometries
 );
 ALTER TABLE buildings ADD CONSTRAINT buildings_ref_toid_len CHECK (length(ref_toid) < 90);
 
+--
+-- Properties table
+--
+-- To store UPRN information normalised - building<->property relationship is typically
+-- one-to-many, may be many-to-many.
+CREATE TABLE IF NOT EXISTS building_properties (
+    -- internal primary key
+    building_property_id serial PRIMARY KEY,
+    -- UPRN
+    uprn bigint,
+    -- Parent should reference UPRN, but assume dataset may be (initially) incomplete
+    parent_uprn bigint,
+    -- Building ID may be null for failed matches
+    building_id integer REFERENCES buildings,
+    -- TOID match provided by AddressBase
+    toid varchar
+);
+
 --
 -- User categories
 --
@@ -104,9 +118,9 @@ CREATE TABLE IF NOT EXISTS logs (
     -- default timestamp to time now
     log_timestamp TIMESTAMP default NOW(),
     -- log document to be extended in application
-    -- log from..to; only changed values (aim to be reversible)
-    log_from jsonb,
-    log_to jsonb,
+    -- log from..to; only changed values (must be reversible)
+    forward_patch jsonb,
+    reverse_patch jsonb,
     -- log user id
     user_id uuid REFERENCES users,
     -- log building id
@@ -116,3 +130,5 @@ CREATE TABLE IF NOT EXISTS logs (
 CREATE INDEX IF NOT EXISTS log_timestamp_idx ON logs ( log_timestamp );
 CREATE INDEX IF NOT EXISTS log_user_idx ON logs ( user_id );
 CREATE INDEX IF NOT EXISTS log_building_idx ON logs ( building_id );
+
+ALTER TABLE buildings ADD COLUMN revision_id bigint REFERENCES logs ( log_id );
diff --git a/migrations/003.index-buildings.down.sql b/migrations/003.index-buildings.down.sql
index 0976b914..a636e9c7 100644
--- a/migrations/003.index-buildings.down.sql
+++ b/migrations/003.index-buildings.down.sql
@@ -1,3 +1,6 @@
 -- Drop building indexes
 DROP INDEX IF EXISTS building_uprn_idx;
+DROP INDEX IF EXISTS uprn_building_idx;
+DROP INDEX IF EXISTS uprn_uprn_idx;
+DROP INDEX IF EXISTS uprn_parent_idx;
 DROP INDEX IF EXISTS building_toid_idx;
diff --git a/migrations/003.index-buildings.up.sql b/migrations/003.index-buildings.up.sql
index 9b71b4aa..56b4ccf7 100644
--- a/migrations/003.index-buildings.up.sql
+++ b/migrations/003.index-buildings.up.sql
@@ -1,7 +1,13 @@
 -- Create building indexes after bulk loading
 
--- UPRN index over buildings
-CREATE INDEX building_uprn_idx ON buildings ( ref_uprn );
+-- Building index over UPRNs (given a building, find UPRNs)
+CREATE INDEX uprn_building_idx ON building_properties ( building_id );
+
+-- UPRN index (given a UPRN, find buildings or parents)
+CREATE INDEX uprn_uprn_idx ON building_properties ( uprn );
+
+-- Parent index over UPRNs (given a UPRN, find children)
+CREATE INDEX uprn_parent_idx ON building_properties ( parent_uprn );
 
 -- TOID index over buildings
 CREATE INDEX building_toid_idx ON buildings ( ref_toid );