feat: add generated area.geom column for improved geocode perfomance

migrations/1770299199726_area_geom.ts

@@ -0,0 +1,29 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { type Kysely, sql } from "kysely";
+
+/**
+ * Add a generated `area.geom` column that is the `geometry` version
+ * of the source `geography` column. At the time of writing, this column
+ * is only used for one query (repositories/Area.ts/findAreasByPoint), as
+ * it is *slightly* less accurate to use geometry columns when working with
+ * geographical data, so should be avoided. However, this function is the
+ * bottleneck when geocoding data records, and using geometry leads to a
+ * 10x speedup, so the accuracy/performance tradeoff works out.
+ */
+
+export async function up(db: Kysely<any>): Promise<void> {
+  await sql`
+    ALTER TABLE area 
+    ADD COLUMN geom geometry(MultiPolygon, 4326) NOT NULL
+    GENERATED ALWAYS AS (geography::geometry) STORED
+  `.execute(db);
+
+  await sql`CREATE INDEX area_area_set_id_geom_gist ON area USING GIST (area_set_id, geom)`.execute(
+    db,
+  );
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await sql`ALTER TABLE area DROP COLUMN geom`.execute(db);
+  await sql`DROP INDEX IF EXISTS area_area_set_id_geom_gist`.execute(db);
+}

src/server/repositories/Area.ts

@@ -73,6 +73,8 @@ const applyAreaWithPointsSelect = (
   ]);
 };
 
+// Uses the generated `geom` column for 10x performance improvement,
+// at the loss of some (potentially negligible) accuracy.
 export async function findAreasByPoint({
   point,
   excludeAreaSetCode,
@@ -93,7 +95,7 @@ export async function findAreasByPoint({
     query = query.where("areaSet.code", "=", includeAreaSetCode);
   }
   return query
-    .where(sql<boolean>`ST_Intersects(geography, ST_GeomFromGeoJson(${point}))`)
+    .where(sql<boolean>`ST_Covers(geom, ST_GeomFromGeoJson(${point}))`)
     .select([
       "area.id",
       "area.code",

src/server/services/database/schema.ts

@@ -4,7 +4,7 @@
  * This file represents the complete database schema as defined by all migrations.
  * It includes all tables, columns, types, constraints, and relationships.
  *
- * Last updated: 2026-01-15
+ * Last updated: 2026-02-05
  * Based on migrations up to: 1764611637231_map_view_inspector_config.ts
  */
 
@@ -39,13 +39,16 @@ export interface Area {
   name: string; // text, NOT NULL
   geography: unknown; // geography (PostGIS), NOT NULL
   areaSetId: number; // bigint, NOT NULL
+  geom: unknown; // geometry(MultiPolygon,4326), GENERATED ALWAYS AS ((geography)::geometry) STORED, NOT NULL
 
   // CONSTRAINTS:
   // - UNIQUE (code, areaSetId)
   // FOREIGN KEYS:
   // - areaSetId -> areaSet.id (CASCADE DELETE, CASCADE UPDATE)
   // INDEXES:
   // - area_geography_gist USING GIST (geography)
+  // - area_area_set_id_geography_gist USING GIST (area_set_id, geography)
+  // - area_area_set_id_geom_gist USING GIST (area_set_id, geom)
 }
 
 // ============================================================================
@@ -82,8 +85,8 @@ export interface Organisation {
  */
 export interface OrganisationUser {
   id: number; // bigserial, NOT NULL
-  organisationId: string; // uuid, NOT NULL
-  userId: string; // uuid, NOT NULL
+  organisationId: string | null; // uuid, NULL
+  userId: string | null; // uuid, NULL
 
   // CONSTRAINTS:
   // - UNIQUE (organisationId, userId)