调整rag_snippet表字段格式

file/tableschema/rag_snippet.sql

@@ -7,9 +7,18 @@ CREATE TABLE `rag_snippet` (
   `snippet_id` varchar(255) COLLATE utf8mb4_bin NOT NULL COMMENT '原始 snippet id',
   `rag_text` text COLLATE utf8mb4_bin NOT NULL COMMENT '用于向量化的拼接文本',
   `merged_json` json NOT NULL COMMENT '合并后的 snippet 对象',
-  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
-  PRIMARY KEY (`rag_item_id`),
+  `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '写入时间，用于分区',
+  `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+  PRIMARY KEY (`rag_item_id`,`created_at`),
   KEY `idx_action_result` (`action_result_id`),
   KEY `idx_workspace` (`workspace_id`),
   KEY `idx_table_version` (`table_id`,`version_ts`)
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin COMMENT='RAG snippet 索引缓存';
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin
+PARTITION BY RANGE COLUMNS (`created_at`) (
+  PARTITION p202401 VALUES LESS THAN ('2024-02-01'),
+  PARTITION p202402 VALUES LESS THAN ('2024-03-01'),
+  PARTITION p202403 VALUES LESS THAN ('2024-04-01'),
+  PARTITION p202404 VALUES LESS THAN ('2024-05-01'),
+  PARTITION p202405 VALUES LESS THAN ('2024-06-01'),
+  PARTITION p_future VALUES LESS THAN (MAXVALUE)
+) COMMENT='RAG snippet 索引缓存';