perf(properties): LATERAL lookups + recommendation by property_id

/api/properties timed out (15s) on just 12 properties: joining the 26M-row
recommendation table on the unindexed plan_id forced a full-table hash, and the
multi-million-row plan/funding joins compounded it.

Rewrite getProperties/getPropertiesCount to read the denormalised model (no
plan_recommendations / recommendation_materials): one-row LATERAL lookups for
target/plan/funding and a recommendation aggregate keyed by the INDEXED
recommendation.property_id, dropping the GROUP BY entirely. ~1s -> instant for a
12-property portfolio.

Also fix the reporting page for new-approach properties (current_sap_points /
current_epc_rating on the property row are unwritten): source avg SAP and the
EPC band distribution from property_baseline_performance (lodged_sap_score /
lodged_epc_band) via new sapSql / epcBandSql helpers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/portfolio/[slug]/(portfolio)/reporting/databaseFunctions.ts

@@ -9,6 +9,8 @@ import {
   energyConsumptionSql,
   estimatedSql,
   isExpiredSql,
+  sapSql,
+  epcBandSql,
 } from "@/lib/services/epcSources";
 
 import type {
@@ -36,7 +38,7 @@ export async function getAverages(
 ): Promise<AverageMetrics> {
   const result = await db.execute<AverageMetrics>(sql`
     SELECT
-      AVG(p.current_sap_points)::float AS avg_sap,
+      AVG(${sapSql})::float AS avg_sap,
       AVG(${carbonSql(sql`e`)})::float AS avg_carbon,
       AVG(${billsSql(sql`e`)})::float AS avg_bills,
       AVG(${energyConsumptionSql(sql`e`)})::float AS avg_energy_consumption
@@ -97,7 +99,7 @@ export async function getCountByEpcBand(
     SELECT *
     FROM (
       SELECT
-        COALESCE(p.current_epc_rating::text, 'Unknown') AS epc,
+        COALESCE((${epcBandSql})::text, 'Unknown') AS epc,
         COUNT(*) FILTER (
           WHERE ${estimatedSql(sql`e`)} = false
         )::int AS actual,

src/app/portfolio/[slug]/utils.ts

@@ -682,7 +682,14 @@ export async function getPropertiesCount(
     FROM property p
     LEFT JOIN property_details_epc epc ON epc.property_id = p.id
     ${newApproachJoins}
-    LEFT JOIN plan pl ON pl.property_id = p.id AND pl.is_default = true
+    LEFT JOIN LATERAL (
+      SELECT id, post_sap_points FROM plan
+      WHERE property_id = p.id
+        AND portfolio_id = p.portfolio_id
+        AND is_default = true
+      ORDER BY created_at DESC
+      LIMIT 1
+    ) pl ON true
     WHERE p.portfolio_id = ${portfolioId}
     ${combinedWhere}
   `);
@@ -714,8 +721,8 @@ export async function getProperties(
       t.epc AS "targetEpc",
       pl.id AS "planId",
       fp.scheme AS "fundingScheme",
-      COALESCE(SUM(r.sap_points), 0) AS "totalRecommendationSapPoints",
-      COALESCE(SUM(r.estimated_cost), 0) AS "totalRecommendationCost",
+      COALESCE(rec.sap_points, 0) AS "totalRecommendationSapPoints",
+      COALESCE(rec.cost, 0) AS "totalRecommendationCost",
       p.landlord_property_id AS "landlordPropertyId",
       p.original_sap_points AS "originalSapPoints",
       p.property_type AS "propertyType",
@@ -729,57 +736,47 @@ export async function getProperties(
       ${mainfuelSql(sql`epc`)} AS mainfuel,
       p.lexiscore AS lexiscore
     FROM property p
-    LEFT JOIN property_targets t
-      ON t.property_id = p.id
-    LEFT JOIN plan pl
-      ON pl.property_id = p.id
-    AND pl.is_default = true
-    LEFT JOIN funding_package fp
-      ON fp.plan_id = pl.id
-    -- Recommendations link to their plan via recommendation.plan_id (the
-    -- plan_recommendations join table is retired). Using plan_id is what makes
-    -- Plan Cost / recommendation SAP populate for new-approach properties.
-    LEFT JOIN recommendation r
-      ON r.plan_id = pl.id
-    AND r.default = true
-    AND r.already_installed = false
+    -- LATERAL one-row lookups keep this query at "12 properties × index probe"
+    -- instead of hash-joining the multi-million-row plan/recommendation tables.
+    LEFT JOIN LATERAL (
+      SELECT epc FROM property_targets
+      WHERE property_id = p.id
+      ORDER BY created_at DESC
+      LIMIT 1
+    ) t ON true
+    LEFT JOIN LATERAL (
+      SELECT * FROM plan
+      WHERE property_id = p.id
+        AND portfolio_id = p.portfolio_id
+        AND is_default = true
+      ORDER BY created_at DESC
+      LIMIT 1
+    ) pl ON true
+    LEFT JOIN LATERAL (
+      SELECT scheme FROM funding_package
+      WHERE plan_id = pl.id
+      LIMIT 1
+    ) fp ON true
+    -- Active (default, not-yet-installed) recommendations for the property,
+    -- read denormalised. We aggregate by recommendation.property_id — the only
+    -- indexed access path (there is NO index on recommendation.plan_id, and the
+    -- table has tens of millions of rows) — and rely on the partial index on
+    -- (default, already_installed). The retired plan_recommendations join table
+    -- is intentionally not used.
+    LEFT JOIN LATERAL (
+      SELECT
+        COALESCE(SUM(sap_points), 0)     AS sap_points,
+        COALESCE(SUM(estimated_cost), 0) AS cost
+      FROM recommendation
+      WHERE property_id = p.id
+        AND "default" = true
+        AND already_installed = false
+    ) rec ON true
     LEFT JOIN property_details_epc epc
       ON epc.property_id = p.id
     ${newApproachJoins}
     WHERE p.portfolio_id = ${portfolioId}
     ${combinedWhere}
-    GROUP BY
-      p.id,
-      p.portfolio_id,
-      p.address,
-      p.postcode,
-      p.status,
-      p.creation_status,
-      p.current_epc_rating,
-      p.current_sap_points,
-      t.epc,
-      pl.id,
-      fp.scheme,
-      p.landlord_property_id,
-      p.original_sap_points,
-      p.property_type,
-      p.built_form,
-      p.tenure,
-      p.year_built,
-      -- legacy + new-source columns referenced by the branched EPC expressions
-      p.updated_at,
-      epc.lodgement_date,
-      epc.is_expired,
-      epc.total_floor_area,
-      epc.co2_emissions,
-      epc.mainfuel,
-      epl.id,
-      epp.id,
-      epl.registration_date,
-      epl.inspection_date,
-      epl.total_floor_area_m2,
-      bp.lodged_co2_emissions_t_per_yr,
-      p.lexiscore
     LIMIT ${limit} OFFSET ${offset};
   `);
 

src/lib/services/epcSources.ts

@@ -85,6 +85,17 @@ export const carbonSql = (e: Alias) =>
 export const energyConsumptionSql = (e: Alias) =>
   sql`CASE WHEN ${isNewApproachSql} THEN bp.lodged_primary_energy_intensity_kwh_per_m2_yr ELSE ${e}.primary_energy_consumption END`;
 
+/**
+ * Baseline SAP score. New: the lodged (gov-registry) score from
+ * property_baseline_performance (the property-row current_sap_points isn't
+ * written for new-approach properties). Legacy: property.current_sap_points.
+ * Swap to `effective_sap_score` for the modelling-adjusted baseline.
+ */
+export const sapSql = sql`CASE WHEN ${isNewApproachSql} THEN bp.lodged_sap_score ELSE p.current_sap_points END`;
+
+/** Baseline EPC band. New: lodged band from property_baseline_performance. Legacy: property.current_epc_rating. */
+export const epcBandSql = sql`CASE WHEN ${isNewApproachSql} THEN bp.lodged_epc_band ELSE p.current_epc_rating END`;
+
 /**
  * Annual energy bill (£). New: sum of the individual cost columns on
  * property_baseline_performance (NULL when no baseline row exists, so it's