Tighten artwork hourly snapshot window queries.

Reduce snapshot work to the active hour window so metrics aggregation stays cheaper on the hot path.

app/Services/Metrics/ArtworkHourlySnapshotWindow.php

@@ -102,42 +102,48 @@ final class ArtworkHourlySnapshotWindow
      */
     public function artworkPeriodDeltas(CarbonInterface|\DateTimeInterface $start, ?int $userId = null): Builder
     {
-        $inWindow = DB::table('artwork_metric_snapshots_hourly as snapshots');
+        $start = \Carbon\Carbon::parse($start);
-        $this->constrainOwner($inWindow, $userId);
+        $baselineFrom = (clone $start)->subHours(self::BASELINE_LOOKBACK_HOURS);
-        $inWindow
-            ->where('snapshots.bucket_hour', '>=', $start)
-            ->groupBy('snapshots.artwork_id')
-            ->select('snapshots.artwork_id')
-            ->selectRaw('MAX(snapshots.views_count) as views_latest')
-            ->selectRaw('MIN(snapshots.views_count) as views_min')
-            ->selectRaw('MAX(snapshots.downloads_count) as downloads_latest')
-            ->selectRaw('MIN(snapshots.downloads_count) as downloads_min')
-            ->selectRaw('MAX(snapshots.favourites_count) as favourites_latest')
-            ->selectRaw('MIN(snapshots.favourites_count) as favourites_min')
-            ->selectRaw('MAX(snapshots.comments_count) as comments_latest')
-            ->selectRaw('MIN(snapshots.comments_count) as comments_min')
-            ->selectRaw('MAX(snapshots.shares_count) as shares_latest')
-            ->selectRaw('MIN(snapshots.shares_count) as shares_min');
 
-        $baselineFrom = \Carbon\Carbon::parse($start)->subHours(self::BASELINE_LOOKBACK_HOURS);
+        // Resolve the three global hourly buckets first. These are cheap indexed
-        $baseline = DB::table('artwork_metric_snapshots_hourly as snapshots');
+        // lookups and avoid aggregating millions of cumulative snapshot rows.
-        $this->constrainOwner($baseline, $userId);
+        $latestBucket = DB::table('artwork_metric_snapshots_hourly')
-        $baseline
+            ->where('bucket_hour', '>=', $start)
-            ->where('snapshots.bucket_hour', '<', $start)
+            ->max('bucket_hour');
-            ->where('snapshots.bucket_hour', '>=', $baselineFrom)
+
-            ->groupBy('snapshots.artwork_id')
+        $firstBucket = DB::table('artwork_metric_snapshots_hourly')
-            ->select('snapshots.artwork_id')
+            ->where('bucket_hour', '>=', $start)
-            ->selectRaw('MAX(snapshots.views_count) as views_baseline')
+            ->min('bucket_hour');
-            ->selectRaw('MAX(snapshots.downloads_count) as downloads_baseline')
+
-            ->selectRaw('MAX(snapshots.favourites_count) as favourites_baseline')
+        $baselineBucket = DB::table('artwork_metric_snapshots_hourly')
-            ->selectRaw('MAX(snapshots.comments_count) as comments_baseline')
+            ->where('bucket_hour', '<', $start)
-            ->selectRaw('MAX(snapshots.shares_count) as shares_baseline');
+            ->where('bucket_hour', '>=', $baselineFrom)
+            ->max('bucket_hour');
+
+        $latest = $this->exactBucketSnapshot(
+            $latestBucket,
+            $userId,
+            'latest',
+        );
+
+        $first = $this->exactBucketSnapshot(
+            $firstBucket,
+            $userId,
+            'min',
+        );
+
+        $baseline = $this->exactBucketSnapshot(
+            $baselineBucket,
+            $userId,
+            'baseline',
+        );
 
         $bornSql = $this->quotedTimestamp($start);
 
         return DB::query()
-            ->fromSub($inWindow, 'win')
+            ->fromSub($latest, 'win')
             ->leftJoinSub($baseline, 'base', 'base.artwork_id', '=', 'win.artwork_id')
+            ->leftJoinSub($first, 'first', 'first.artwork_id', '=', 'win.artwork_id')
             ->join('artworks', 'artworks.id', '=', 'win.artwork_id')
             ->select('win.artwork_id')
             ->selectRaw($this->deltaExpression('views', $bornSql) . ' as views_delta')
@@ -147,6 +153,7 @@ final class ArtworkHourlySnapshotWindow
             ->selectRaw($this->deltaExpression('shares', $bornSql) . ' as shares_delta');
     }
 
+
     /**
      * @return array{oldest_bucket: ?string, newest_bucket: ?string, coverage_days: float, window_complete: bool, requested_days: int}
      */
@@ -194,6 +201,34 @@ final class ArtworkHourlySnapshotWindow
             ->whereNull('owner_artworks.deleted_at');
     }
 
+    private function exactBucketSnapshot(
+        ?string $bucket,
+        ?int $userId,
+        string $suffix,
+    ): Builder {
+        $query = DB::table('artwork_metric_snapshots_hourly as snapshots');
+
+        if (DB::connection()->getDriverName() === 'mysql') {
+            $query->forceIndex('idx_bucket_artwork');
+        }
+
+        $this->constrainOwner($query, $userId);
+
+        if ($bucket === null) {
+            $query->whereRaw('1 = 0');
+        } else {
+            $query->where('snapshots.bucket_hour', $bucket);
+        }
+
+        return $query
+            ->select('snapshots.artwork_id')
+            ->selectRaw("snapshots.views_count as views_{$suffix}")
+            ->selectRaw("snapshots.downloads_count as downloads_{$suffix}")
+            ->selectRaw("snapshots.favourites_count as favourites_{$suffix}")
+            ->selectRaw("snapshots.comments_count as comments_{$suffix}")
+            ->selectRaw("snapshots.shares_count as shares_{$suffix}");
+    }
+
     private function quotedTimestamp(CarbonInterface|\DateTimeInterface $start): string
     {
         return DB::getPdo()->quote(\Carbon\Carbon::parse($start)->toDateTimeString());
@@ -202,7 +237,7 @@ final class ArtworkHourlySnapshotWindow
     private function deltaExpression(string $metric, string $bornSql): string
     {
         $latest = "COALESCE(win.{$metric}_latest, 0)";
-        $min = "COALESCE(win.{$metric}_min, 0)";
+        $min = "COALESCE(first.{$metric}_min, 0)";
         $base = "base.{$metric}_baseline";
         $bornInWindow = "COALESCE(artworks.published_at, artworks.created_at) >= {$bornSql}";
         $observed = $this->clampNonNegative("{$latest} - {$min}");