diff --git a/modules/EcommerceFinance/Repositories/CourierFreightReconciliationMirrorRepository.php b/modules/EcommerceFinance/Repositories/CourierFreightReconciliationMirrorRepository.php
index 6853215e..a366da48 100644
--- a/modules/EcommerceFinance/Repositories/CourierFreightReconciliationMirrorRepository.php
+++ b/modules/EcommerceFinance/Repositories/CourierFreightReconciliationMirrorRepository.php
@@ -215,15 +215,26 @@ class CourierFreightReconciliationMirrorRepository
         // One expensive aggregate at a time, including requests for different filters.
         $lock = Cache::lock('courier-freight-summary:calculation', 360);
         if (! $lock->get()) return null;
-        $previousTimeout = null;
+        $previousSettings = [];
         try {
             if (is_array($cached = Cache::get($key))) return $cached;
             if ($this->connection->getDriverName() === 'mysql') {
-                $previousTimeout = $this->connection->selectOne('SELECT @@SESSION.max_statement_time AS value')->value;
-                $this->connection->statement('SET SESSION max_statement_time=300');
+                $settings = ['max_statement_time' => 300];
+                if (array_filter($filters, static fn ($value): bool => trim((string) $value) !== '') === []) {
+                    $settings += [
+                        'optimizer_switch' => 'derived_merge=off,derived_with_keys=off',
+                        'join_cache_level' => 8,
+                        'join_buffer_size' => 16777216,
+                        'join_buffer_space_limit' => 33554432,
+                    ];
+                }
+                foreach ($settings as $name => $value) {
+                    $previousSettings[$name] = $this->connection->selectOne('SELECT @@SESSION.' . $name . ' AS value')->value;
+                    $this->setSummarySessionSetting($name, $value);
+                }
             }
             $asOf = now()->toDateTimeString();
-            $row = $this->filteredQuery($filters)->selectRaw(
+            $row = $this->summaryQuery($filters)->selectRaw(
                 'COUNT(d.id) AS aggregate_count, COALESCE(SUM(o.freight), 0) AS freight',
             )->first();
             $summary = ['count' => (int) $row->aggregate_count, 'freight' => (float) $row->freight, 'computed_at' => $asOf];
@@ -231,23 +242,72 @@ class CourierFreightReconciliationMirrorRepository
             return $summary;
         } finally {
             try {
-                if ($previousTimeout !== null) $this->connection->statement('SET SESSION max_statement_time=' . (float) $previousTimeout);
+                foreach (array_reverse($previousSettings, true) as $name => $value) {
+                    $this->setSummarySessionSetting($name, $value);
+                }
             } finally {
                 $lock->release();
             }
         }
     }
 
+    private function setSummarySessionSetting(string $name, mixed $value): void
+    {
+        if ($name === 'optimizer_switch') {
+            $this->connection->statement('SET SESSION optimizer_switch=?', [$value]);
+            return;
+        }
+        // MariaDB rejects quoted numeric values for these session variables.
+        // Names come only from the fixed settings map above.
+        $this->connection->statement('SET SESSION ' . $name . '=' . (float) $value);
+    }
+
     private function summaryCacheKey(array $filters): string
     {
         $filters = array_filter(array_map(static fn ($value): string => trim((string) $value), $filters), static fn (string $value): bool => $value !== '');
         ksort($filters);
-        return 'courier-freight-summary:v1:' . hash('sha256', json_encode($filters));
+        return 'courier-freight-summary:v3:' . hash('sha256', json_encode($filters));
     }
 
-    private function filteredQuery(array $filters, bool $includeRelations = true): Builder
+    /** Materialize latest associations once; use compact collation-aware hash joins for the full scan. */
+    private function summaryQuery(array $filters = []): Builder
     {
-        $query = ($includeRelations ? $this->detailQuery() : $this->connection->table($this->datasets->get(self::DETAILS_DATASET)->targetTable() . ' as d'))
+        $activeFilters = array_filter($filters, static fn ($value): bool => trim((string) $value) !== '');
+        if ($activeFilters !== []) {
+            $ids = $this->filteredQuery($filters, ($filters['express_name'] ?? '') !== '')->select('d.id')->distinct();
+            return $this->detailQuery($ids);
+        }
+        $columns = ['so_id', 'io_id'];
+        $lookup = fn (string $column): string => $this->connection->getDriverName() === 'mysql'
+            ? 'CRC32(WEIGHT_STRING(RTRIM(' . $column . ')))'
+            : 'SUBSTR(' . $column . ', 1, 64)';
+        $extension = $this->latestSummaryProjection(self::EXTENSION_DATASET, 'so_id', $columns)
+            ->selectRaw($lookup('candidate.so_id') . ' AS lookup_key');
+        $outbound = $this->latestSummaryProjection(self::OUTBOUND_DATASET, 'io_id', ['io_id', 'freight']);
+        $query = $this->connection->table($this->datasets->get(self::DETAILS_DATASET)->targetTable() . ' as d')
+            ->leftJoinSub($extension, 'x', static function ($join) use ($lookup): void {
+                $join->whereRaw('x.lookup_key = ' . $lookup('d.so_id'))
+                    // Keep the full comparison: a hash collision must never
+                    // combine different orders or multiply freight amounts.
+                    ->whereRaw("COALESCE(x.so_id, '') = COALESCE(d.so_id, '')");
+            })
+            ->leftJoinSub($outbound, 'o', 'o.io_id', '=', 'x.io_id');
+        return $this->filteredQuery([], true, $query);
+    }
+
+    private function latestSummaryProjection(string $dataset, string $relation, array $columns): Builder
+    {
+        $table = $this->datasets->get($dataset)->targetTable();
+        $ids = $this->connection->table($table)->select($relation)->selectRaw('MAX(Id) AS latest_id')->groupBy($relation)->orderByRaw('NULL');
+        return $this->connection->query()->fromSub($ids, 'latest_ids')
+            ->join($table . ' as candidate', static function ($join) use ($relation): void {
+                $join->on('latest_ids.' . $relation, '=', 'candidate.' . $relation)->on('latest_ids.latest_id', '=', 'candidate.Id');
+            })->select(array_map(static fn (string $column): string => 'candidate.' . $column, $columns));
+    }
+
+    private function filteredQuery(array $filters, bool $includeRelations = true, ?Builder $base = null): Builder
+    {
+        $query = ($base ?? ($includeRelations ? $this->detailQuery() : $this->connection->table($this->datasets->get(self::DETAILS_DATASET)->targetTable() . ' as d')))
             ->whereNotNull('d.logistic_id')->where('d.logistic_id', '!=', '');
         $this->containsFilter($query, 'd.logistic_id', $filters['express_no'] ?? '');
 
diff --git a/tests/Unit/EcommerceFinance/CourierFreightReconciliationMirrorRepositoryTest.php b/tests/Unit/EcommerceFinance/CourierFreightReconciliationMirrorRepositoryTest.php
index c36159d0..1878dc2e 100644
--- a/tests/Unit/EcommerceFinance/CourierFreightReconciliationMirrorRepositoryTest.php
+++ b/tests/Unit/EcommerceFinance/CourierFreightReconciliationMirrorRepositoryTest.php
@@ -209,6 +209,24 @@ class CourierFreightReconciliationMirrorRepositoryTest extends TestCase
         $db->disableQueryLog();
     }
 
+    public function test_summary_lookup_keeps_full_long_order_identifiers_distinct(): void
+    {
+        $this->markReady();
+        $db = DB::connection('business_mirror');
+        $prefix = str_repeat('X', 64);
+        $db->table('js_jst_order_express_details')->insert(['id' => 1, 'logistic_id' => 'A', 'so_id' => $prefix . 'A']);
+        $db->table('js_jst_send_data_view_extension')->insert([
+            ['Id' => 1, 'so_id' => $prefix . 'A', 'io_id' => 1],
+            ['Id' => 2, 'so_id' => $prefix . 'B', 'io_id' => 2],
+        ]);
+        $db->table('js_jst_sales_outbound_info')->insert([
+            ['Id' => 1, 'io_id' => 1, 'freight' => 1], ['Id' => 2, 'io_id' => 2, 'freight' => 2],
+        ]);
+        $summary = $this->repository->summarize([]);
+        $this->assertSame(1, $summary['count']);
+        $this->assertSame(1.0, $summary['freight']);
+    }
+
     private function markReady(): void
     {
         $now = now()->toDateTimeString();