From 9d2901aaf98032ab4098d2285cc1317be425b3b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Bombeck?= <mbombeck@gmail.com>
Date: Thu, 21 May 2026 17:35:10 +0200
Subject: [PATCH] refactor(rollups): retire v1.4.39 W-SUM legacy-NULL UNION
 discovery arm

The `sum_value IS NULL` UNION arm in `enqueueBootTimeRollupBackfill`
was added in v1.4.39 W-SUM to converge DAY rollup rows that pre-dated
the writer change. Production data has since converged, so the arm is
a permanent no-op seq scan over `measurement_rollups`. Per-day missing
coverage remains the sole discovery anchor.

Drops the legacy text-anchor unit test. The read-side `mean * count`
fallback in `/api/dashboard/summary` retains legacy-row readability
and stays covered by its dedicated route test.
---
 .../__tests__/measurement-rollups.test.ts     | 24 ----------
 src/lib/rollups/measurement-rollups.ts        | 47 ++++++++-----------
 2 files changed, 19 insertions(+), 52 deletions(-)

diff --git a/src/lib/rollups/__tests__/measurement-rollups.test.ts b/src/lib/rollups/__tests__/measurement-rollups.test.ts
index f5d056e85..7a5891898 100644
--- a/src/lib/rollups/__tests__/measurement-rollups.test.ts
+++ b/src/lib/rollups/__tests__/measurement-rollups.test.ts
@@ -543,30 +543,6 @@ describe("enqueueBootTimeRollupBackfill", () => {
     expect(bossSend).not.toHaveBeenCalled();
   });
 
-  // v1.4.39 W-SUM — the discovery query now unions in users whose
-  // existing DAY rollup rows carry `sum_value IS NULL`. Re-folding
-  // converges those rows because `persistRollupRows` always writes the
-  // new column on upsert; the union keeps the per-day missing-coverage
-  // gap (v1.4.39.1) and the legacy-NULL backfill on the same indexed
-  // pass.
-  it("includes the sum_value IS NULL branch in the discovery query", async () => {
-    getGlobalBossMock.mockReturnValue({ send: bossSend });
-    queryRaw.mockResolvedValueOnce([{ id: "user-with-legacy-rollups" }]);
-    bossSend.mockResolvedValueOnce("job-id");
-
-    const result = await enqueueBootTimeRollupBackfill();
-
-    expect(result).toEqual({ enqueued: 1, skipped: 0, error: null });
-    // The discovery SQL surfaces both per-day missing coverage AND
-    // legacy NULL sum_value rows under one UNION. The text-anchor is
-    // the only durable assertion at the unit level — the integration
-    // suite covers the planner shape on real Postgres.
-    const sqlParts = queryRaw.mock.calls[0][0] as TemplateStringsArray;
-    const sqlText = Array.isArray(sqlParts) ? sqlParts.join("?") : "";
-    expect(sqlText).toContain("sum_value");
-    expect(sqlText).toContain("UNION");
-  });
-
   // v1.4.39.1 — the discovery anchor moved from per-type to per-day so
   // accounts whose Withings sync / `/api/import` / admin restore wrote
   // measurements without firing the rollup write hook get re-enqueued
diff --git a/src/lib/rollups/measurement-rollups.ts b/src/lib/rollups/measurement-rollups.ts
index 897789a30..a6de1b45f 100644
--- a/src/lib/rollups/measurement-rollups.ts
+++ b/src/lib/rollups/measurement-rollups.ts
@@ -752,35 +752,26 @@ export async function enqueueBootTimeRollupBackfill(): Promise<{
     // index path. The LEFT JOIN walks `measurement_rollups` against
     // its composite primary key.
     //
-    // v1.4.39 W-SUM — the discovery also surfaces users whose existing
-    // DAY rollup rows carry `sum_value IS NULL`. Those rows pre-date
-    // the v1.4.39 writer change; re-folding the user converges them
-    // because `persistRollupRows` always writes the new column on
-    // upsert. The union runs in one query so the per-day coverage gap
-    // and the legacy-NULL backfill share a single planner pass.
+    // v1.4.41 — the v1.4.39 W-SUM legacy-NULL `sum_value` UNION arm
+    // has been retired. Marc's tenant converged at v1.4.40, so the
+    // arm was a permanent no-op seq scan over `measurement_rollups`.
+    // Per-day missing coverage remains the sole discovery anchor.
     const users = await prisma.$queryRaw<Array<{ id: string }>>`
-      SELECT DISTINCT id FROM (
-        SELECT DISTINCT mt."user_id" AS id
-        FROM (
-          SELECT DISTINCT
-            m."user_id",
-            m."type",
-            date_trunc('day', m."measured_at") AS bucket_start
-          FROM measurements m
-          WHERE m."deleted_at" IS NULL
-        ) mt
-        LEFT JOIN measurement_rollups r
-          ON  r."user_id"     = mt."user_id"
-          AND r."type"        = mt."type"
-          AND r."granularity" = 'DAY'
-          AND r."bucket_start" = mt."bucket_start"
-        WHERE r."bucket_start" IS NULL
-        UNION
-        SELECT DISTINCT r2."user_id" AS id
-        FROM measurement_rollups r2
-        WHERE r2."granularity" = 'DAY'
-          AND r2."sum_value"   IS NULL
-      ) discovery
+      SELECT DISTINCT mt."user_id" AS id
+      FROM (
+        SELECT DISTINCT
+          m."user_id",
+          m."type",
+          date_trunc('day', m."measured_at") AS bucket_start
+        FROM measurements m
+        WHERE m."deleted_at" IS NULL
+      ) mt
+      LEFT JOIN measurement_rollups r
+        ON  r."user_id"     = mt."user_id"
+        AND r."type"        = mt."type"
+        AND r."granularity" = 'DAY'
+        AND r."bucket_start" = mt."bucket_start"
+      WHERE r."bucket_start" IS NULL
     `;
 
     if (users.length === 0) {