diff --git a/docs/业务数据分层存储.md b/docs/业务数据分层存储.md
index a5c53ab1..c1d69fff 100644
--- a/docs/业务数据分层存储.md
+++ b/docs/业务数据分层存储.md
@@ -56,7 +56,7 @@
 
 1. `business-data:plan` 只读输出固定数据集、页面用途、目标层、同步策略、当前表体量与迁移阶段；固定数据集漏配或多配即失败。
 2. `business-data:backfill-columnar <dataset>` 只从现有 MariaDB 镜像按 `_mirror_key` 断点读取，不连接上游；读取范围固定在任务启动时的 `_mirror_synced_at` 截止点。
-3. ClickHouse 表使用 `ReplacingMergeTree`，以 `_mirror_key` 为排序/去重键，并按其哈希固定分为 32 个分区；同一业务键的所有版本必定落在同一分区。
+3. ClickHouse 表使用 `ReplacingMergeTree`，以 `(_mirror_generation, _mirror_key)` 为排序/去重键，并按业务键哈希固定分为 32 个分区；同一代次内的业务键更新会被正确折叠，不同代次会同时保留。建表检查发现旧表缺少代次键时会拒绝继续回填，必须先以影子表完成可回滚修复。
 4. 回填结束同时核对截止点精确行数、ClickHouse `FINAL` 行数和唯一键数；不一致只记录失败，不切换页面。
 5. `--archive` 在对账后把 32 个哈希分区分别输出为 Parquet，经现有私有七牛 S3 磁盘流式上传；每个对象记录路径、行数、字节数和逻辑校验值。
 6. 本阶段没有“激活”或“删除”命令。页面切换与 MariaDB 清理必须在各 Repository 的 ClickHouse 查询完成真实页面验收后另行提交，避免有人只执行一条命令就绕过保护门。
diff --git a/modules/EcommerceFinance/Services/ClickHouseSchemaManager.php b/modules/EcommerceFinance/Services/ClickHouseSchemaManager.php
index 19cedaea..f5612326 100644
--- a/modules/EcommerceFinance/Services/ClickHouseSchemaManager.php
+++ b/modules/EcommerceFinance/Services/ClickHouseSchemaManager.php
@@ -32,17 +32,18 @@ class ClickHouseSchemaManager
         $definitions[] = '`_mirror_version` UInt64';
 
         // Hash partitioning keeps every version of one business key in the same
-        // partition, so ReplacingMergeTree can reconcile updates without relying
-        // on a business date that might later be corrected upstream.
+        // partition. The generation must also be part of the replacement key:
+        // otherwise a newer backfill generation would erase the retained one.
         $sql = sprintf(
             'CREATE TABLE IF NOT EXISTS %s (%s) '
             . 'ENGINE = ReplacingMergeTree(_mirror_version) '
             . 'PARTITION BY modulo(cityHash64(_mirror_key), 32) '
-            . 'ORDER BY (_mirror_key) SETTINGS index_granularity = 8192',
+            . 'ORDER BY (_mirror_generation, _mirror_key) SETTINGS index_granularity = 8192',
             $this->clickHouse->qualifiedTable($dataset->targetTable()),
             implode(', ', $definitions),
         );
         $this->clickHouse->command($sql);
+        $this->assertGenerationScopedSortingKey($dataset);
 
         return $columns;
     }
@@ -58,6 +59,22 @@ class ClickHouseSchemaManager
         ) === 1;
     }
 
+    private function assertGenerationScopedSortingKey(BusinessMirrorDataset $dataset): void
+    {
+        $sortingKey = (string) $this->clickHouse->scalar(
+            'SELECT sorting_key FROM system.tables '
+            . 'WHERE database = {database:String} AND name = {table:String}',
+            [
+                'database' => (string) config('business_data.clickhouse.database', 'caiwu_business_analytics'),
+                'table' => $dataset->targetTable(),
+            ],
+        );
+        $normalized = strtolower((string) preg_replace('/[`()\s]+/', '', $sortingKey));
+        if ($normalized !== '_mirror_generation,_mirror_key') {
+            throw new RuntimeException('business_data_columnar_generation_key_mismatch');
+        }
+    }
+
     /** @param array<string,mixed> $column */
     private function type(array $column): string
     {
diff --git a/tests/Unit/EcommerceFinance/ColumnarBusinessMirrorRepositoryTest.php b/tests/Unit/EcommerceFinance/ColumnarBusinessMirrorRepositoryTest.php
index f974a899..9bc51745 100644
--- a/tests/Unit/EcommerceFinance/ColumnarBusinessMirrorRepositoryTest.php
+++ b/tests/Unit/EcommerceFinance/ColumnarBusinessMirrorRepositoryTest.php
@@ -56,13 +56,18 @@ class ColumnarBusinessMirrorRepositoryTest extends TestCase
         $client = Mockery::mock(ClickHouseClient::class);
         $client->shouldReceive('identifier')->times(4)->andReturnUsing(static fn (string $name): string => '`' . $name . '`');
         $client->shouldReceive('qualifiedTable')->once()->with('fact_rows')->andReturn('`analytics`.`fact_rows`');
+        $client->shouldReceive('scalar')->once()->withArgs(static fn (string $sql, array $parameters): bool =>
+            str_contains($sql, 'SELECT sorting_key FROM system.tables')
+            && $parameters['database'] === 'caiwu_business_analytics'
+            && $parameters['table'] === 'fact_rows'
+        )->andReturn('_mirror_generation, _mirror_key');
         $client->shouldReceive('command')->once()->withArgs(static fn (string $sql): bool =>
             str_contains($sql, '`flag` Nullable(UInt8)')
             && str_contains($sql, '`amount` Nullable(Decimal(20, 4))')
             && str_contains($sql, "`updated_at` Nullable(DateTime64(6, 'Asia/Shanghai'))")
             && str_contains($sql, 'ENGINE = ReplacingMergeTree(_mirror_version)')
             && str_contains($sql, 'PARTITION BY modulo(cityHash64(_mirror_key), 32)')
-            && str_contains($sql, 'ORDER BY (_mirror_key)')
+            && str_contains($sql, 'ORDER BY (_mirror_generation, _mirror_key)')
         );
 
         $columns = (new ClickHouseSchemaManager($source, $client, $placements))->ensure($dataset);
@@ -70,6 +75,27 @@ class ColumnarBusinessMirrorRepositoryTest extends TestCase
         $this->assertCount(4, $columns);
     }
 
+    public function test_columnar_schema_rejects_a_generation_unsafe_existing_sorting_key(): void
+    {
+        $dataset = $this->dataset();
+        $source = Mockery::mock(BusinessMirrorSchemaManager::class);
+        $source->shouldReceive('columns')->once()->andReturn([
+            ['column_name' => 'Id', 'data_type' => 'int'],
+        ]);
+        $placements = Mockery::mock(BusinessDataPlacement::class);
+        $placements->shouldReceive('targetStore')->once()->with('source.schema.fact')->andReturn('clickhouse');
+        $client = Mockery::mock(ClickHouseClient::class);
+        $client->shouldReceive('identifier')->once()->with('Id')->andReturn('`Id`');
+        $client->shouldReceive('qualifiedTable')->once()->with('fact_rows')->andReturn('`analytics`.`fact_rows`');
+        $client->shouldReceive('command')->once();
+        $client->shouldReceive('scalar')->once()->andReturn('_mirror_key');
+
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('business_data_columnar_generation_key_mismatch');
+
+        (new ClickHouseSchemaManager($source, $client, $placements))->ensure($dataset);
+    }
+
     private function dataset(): BusinessMirrorDataset
     {
         return new class implements BusinessMirrorDataset {