diff --git a/app/agent/data_tools.py b/app/agent/data_tools.py
index bf5646b..8ce5ec7 100644
--- a/app/agent/data_tools.py
+++ b/app/agent/data_tools.py
@@ -7,7 +7,7 @@ apply_actions 里的 $query 也通过 DataContext.query 执行，见 tools.py
 上下文类型因 agent 而异，所以写 ToolRuntime[Any]（不写类型参数时按 None 处理，序列化会告警）
 """
 
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Annotated, Any
 
@@ -17,7 +17,8 @@ from pydantic import Field
 
 from app.config import settings
 from app.datafiles.query import MAX_ROWS, QueryError, QueryResult, run_query
-from app.schemas.data_file import RequestDataFile, RequestDataTable
+from app.datafiles.storage import table_path
+from app.schemas.data_file import DataFileRecord, DataTable
 
 # 列超过这么多时，不指定 columns 只返回列名和类型，避免一次塞进太多概况
 BRIEF_COLUMNS = 50
@@ -25,9 +26,12 @@ BRIEF_COLUMNS = 50
 
 @dataclass(frozen=True)
 class DataContext:
-    files: tuple[RequestDataFile, ...] = ()
+    """本次运行可用的数据文件；root 是数据文件的根目录，Parquet 路径由它和文件记录算出"""
 
-    def find(self, name: str) -> tuple[RequestDataFile, RequestDataTable] | None:
+    files: tuple[DataFileRecord, ...] = ()
+    root: Path = field(default_factory=lambda: settings.data_file_dir)
+
+    def find(self, name: str) -> tuple[DataFileRecord, DataTable] | None:
         for file in self.files:
             for table in file.tables:
                 if table.table == name:
@@ -36,7 +40,7 @@ class DataContext:
 
     def paths(self) -> dict[str, Path]:
         return {
-            table.table: Path(table.path)
+            table.table: table_path(self.root, file.file_id, table)
             for file in self.files
             for table in file.tables
         }
@@ -86,7 +90,7 @@ def describe_data(
     if found is None:
         return _error(runtime, f"没有表 {table}，可用的表：{_table_list(data)}")
     file, item = found
-    profiled: list[dict[str, Any]] = item.profile["columns"]
+    profiled = item.profile.columns
     result: dict[str, Any] = {
         "table": item.table,
         "label": item.label,
@@ -94,20 +98,25 @@ def describe_data(
     }
     if columns is None and len(profiled) > BRIEF_COLUMNS:
         result["columns"] = [
-            {key: column[key] for key in ("name", "type", "format") if key in column}
+            column.model_dump(
+                mode="json", include={"name", "type", "format"}, exclude_none=True
+            )
             for column in profiled
         ]
         result["note"] = (
             f"共 {len(profiled)} 列，只列出列名和类型；用 columns 指定列查看详细概况和样例"
         )
     else:
-        index = {column["name"]: position for position, column in enumerate(profiled)}
+        index = {column.name: position for position, column in enumerate(profiled)}
         names = list(index) if columns is None else list(dict.fromkeys(columns))
         positions = [index[name] for name in names if name in index]
-        result["columns"] = [profiled[position] for position in positions]
+        result["columns"] = [
+            profiled[position].model_dump(mode="json", exclude_none=True)
+            for position in positions
+        ]
         # 样例行的值和 columns 一一对应
         result["sample_rows"] = [
-            [row[position] for position in positions] for row in item.profile["sample"]
+            [row[position] for position in positions] for row in item.profile.sample
         ]
         if missing := [name for name in names if name not in index]:
             result["missing_columns"] = missing
diff --git a/app/api/files.py b/app/api/files.py
index 4df4a1b..28b0517 100644
--- a/app/api/files.py
+++ b/app/api/files.py
@@ -3,13 +3,17 @@
 from typing import Annotated, Literal, get_args
 
 from fastapi import APIRouter, Depends, File, Form, Query, Request, UploadFile
+from fastapi.responses import JSONResponse
+from starlette.types import ASGIApp, Receive, Scope, Send
 
-from app.common.response import ApiResponse, success_response
+from app.common.response import ApiResponse, error_content, success_response
 from app.core.auth import get_current_user
+from app.datafiles.base import MAX_TABLE_ROWS
 from app.datafiles.service import (
     MAX_FILES_PER_CONVERSATION,
     PARSE_CONCURRENCY,
     DataFileService,
+    file_too_large,
 )
 from app.schemas.base import NonBlankString
 from app.schemas.data_file import (
@@ -31,18 +35,55 @@ from app.schemas.user import CurrentUser
 limits_router = APIRouter(prefix="/files", tags=["DataFile"])
 router = APIRouter(prefix="/files", tags=["DataFile"])
 
-# 文件选择框的过滤条件；后端按文件内容识别格式，不看扩展名
-# 翻页取表数据：单页上限，和一张表最多的行数（100 万）
+# 翻页取表数据：单页上限，offset 不超过一张表最多的行数
 MAX_PAGE_ROWS = 500
-MAX_OFFSET = 1_000_000
+MAX_OFFSET = MAX_TABLE_ROWS
 
+# 文件选择框的过滤条件；后端按文件内容识别格式，不看扩展名
 ACCEPT = ".csv,.tsv,.txt,.xlsx,.xls,.xlsb,.json,.jsonl,.ndjson,.parquet"
 
+# 上传的请求体比文件本身多出 multipart 的分隔行、字段名和会话 ID
+UPLOAD_OVERHEAD_BYTES = 64 * 1024
+
 
 def _service(request: Request) -> DataFileService:
     return request.app.state.data_file_service
 
 
+class UploadSizeLimit:
+    """上传接口在读取请求体之前按 Content-Length 拒绝过大的请求
+
+    FastAPI 会先把整个 multipart 请求体收完、写进临时文件，再调用接口函数；
+    只在 DataFileService 里边写边查大小的话，超大的上传已经占满了带宽和磁盘
+    """
+
+    def __init__(self, app: ASGIApp, path: str):
+        self.app = app
+        self.path = path
+
+    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
+        if (
+            scope["type"] == "http"
+            and scope["method"] == "POST"
+            and scope["path"] == self.path
+            and (rejection := self._reject(scope)) is not None
+        ):
+            await rejection(scope, receive, send)
+            return
+        await self.app(scope, receive, send)
+
+    @staticmethod
+    def _reject(scope: Scope) -> JSONResponse | None:
+        max_mb = scope["app"].state.data_file_service.max_mb
+        length = dict(scope["headers"]).get(b"content-length")
+        if length is None or not length.isdigit():
+            return JSONResponse(error_content(411, "缺少 Content-Length"), 411)
+        if int(length) > max_mb * 1024 * 1024 + UPLOAD_OVERHEAD_BYTES:
+            error = file_too_large(max_mb)
+            return JSONResponse(error_content(error.code, error.msg), error.code)
+        return None
+
+
 def _detail(record: DataFileRecord) -> DataFileDetail:
     # 按接口模型重新校验，去掉 owner_id、sha256、列概况等只在后端用的字段
     return DataFileDetail.model_validate(record.model_dump())
diff --git a/app/datafiles/aggregate.py b/app/datafiles/aggregate.py
index aff0d07..513becb 100644
--- a/app/datafiles/aggregate.py
+++ b/app/datafiles/aggregate.py
@@ -3,9 +3,18 @@
 列名、别名一律通过 quote_identifier 引用，请求里的字符串不会拼进 SQL 的其他位置
 """
 
+from pathlib import Path
+
+from app.config import settings
 from app.core.exceptions import BizException
-from app.datafiles.query import quote_identifier
-from app.schemas.data_file import AggregateRequest, DataColumn, GroupBy, Metric
+from app.datafiles.query import quote_identifier, run_query
+from app.schemas.data_file import (
+    AggregateRequest,
+    AggregateResult,
+    DataColumn,
+    GroupBy,
+    Metric,
+)
 
 # 只能用于数值列的聚合；其余聚合对列类型没有要求
 NUMBER_ONLY = {"sum", "avg"}
@@ -20,7 +29,28 @@ TEMPLATES = {
 TIME_TYPES = {"date", "datetime"}
 
 
-def build_aggregate_sql(
+def run_aggregate(
+    path: Path, request: AggregateRequest, columns: list[DataColumn]
+) -> AggregateResult:
+    """对一张表的 Parquet 执行汇总；接口和上传后的分析共用
+
+    请求不合法时抛 422；执行失败（包括文件已被删除）抛 QueryError
+    """
+    sql, names = _build_sql(request, columns)
+    result = run_query(
+        sql,
+        {"t": path},
+        timeout=settings.data_query_timeout,
+        max_rows=request.limit,
+    )
+    return AggregateResult(
+        columns=names,
+        rows=[dict(zip(names, row)) for row in result.rows],
+        truncated=result.truncated,
+    )
+
+
+def _build_sql(
     request: AggregateRequest, columns: list[DataColumn]
 ) -> tuple[str, list[str]]:
     """返回 SQL（表名固定为 t）和结果列名；请求不合法时抛 422
diff --git a/app/datafiles/base.py b/app/datafiles/base.py
index 4896947..4c355a6 100644
--- a/app/datafiles/base.py
+++ b/app/datafiles/base.py
@@ -1,4 +1,6 @@
-"""数据文件各环节共用的异常和上限"""
+"""数据文件各环节共用的异常、上限和警告文案的写法"""
+
+from collections.abc import Sequence
 
 # 每张表的数据行数上限
 MAX_TABLE_ROWS = 1_000_000
@@ -26,6 +28,11 @@ def where(sheet: str | None) -> str:
     return f"{sheet}：" if sheet else ""
 
 
+def brief(items: Sequence[str], sep: str = "、", limit: int = 5) -> str:
+    """警告里列举的内容最多写 limit 个，多出的用“等”概括"""
+    return sep.join(items[:limit]) + ("等" if len(items) > limit else "")
+
+
 def rows_exceeded(sheet: str | None) -> DataFileError:
     return DataFileError(
         422, f"{where(sheet)}超过 {MAX_TABLE_ROWS // 10_000} 万行，请拆分后上传"
diff --git a/app/datafiles/columns.py b/app/datafiles/columns.py
index 7077cb9..c2077ec 100644
--- a/app/datafiles/columns.py
+++ b/app/datafiles/columns.py
@@ -15,7 +15,7 @@ from typing import Any
 
 import pyarrow as pa
 
-from app.datafiles.base import where
+from app.datafiles.base import brief, where
 from app.schemas.data_file import DataColumn, ParseWarning
 
 NULL_TOKENS = {"", "-", "--", "—", "——", "N/A", "n/a", "NULL", "null", "#N/A"}
@@ -63,7 +63,7 @@ def clean_names(
     """去掉空白和换行；空列名按位置命名，重复列名加后缀"""
     names, changes, seen = [], [], set()
     for position, value in enumerate(raw, start=1):
-        name = re.sub(r"\s*[\r\n]+\s*", " ", label_text(value)).strip()
+        name = re.sub(r"\s*[\r\n]+\s*", " ", as_text(value)).strip()
         if not name:
             name = f"列{position}"
             changes.append(f"第 {position} 列没有列名，命名为「{name}」")
@@ -77,19 +77,9 @@ def clean_names(
         names.append(name)
     if not changes:
         return names, None
-    shown = "；".join(changes[:5]) + ("等" if len(changes) > 5 else "")
-    return names, ParseWarning(code="column_renamed", message=f"{where(sheet)}{shown}")
-
-
-def label_text(value: Any) -> str:
-    """表头单元格转成列名；Excel 里年份等数字表头读出来是 2025.0"""
-    if value is None:
-        return ""
-    if isinstance(value, float) and value.is_integer():
-        return str(int(value))
-    if isinstance(value, (date, time)):
-        return value.isoformat()
-    return str(value)
+    return names, ParseWarning(
+        code="column_renamed", message=f"{where(sheet)}{brief(changes, '；')}"
+    )
 
 
 def build_columns(
@@ -257,29 +247,29 @@ def classify(value: Any) -> tuple[str, Any]:
 
 
 def parse_number(text: str) -> int | float | None:
-    """千分位和货币符号可以有；有前导零或 16 位以上的数字串是编号，不算数值"""
-    # 最常见的纯数字走快速路径，不用正则
-    if text.isdigit():
-        if len(text) >= MIN_ID_DIGITS or (len(text) > 1 and text[0] == "0"):
-            return None
-        return int(text)
+    """千分位和货币符号可以有；有前导零或 16 位以上的数字串是编号，不算数值
+
+    判断数字一律用 isdecimal：isdigit 对 ²、① 也返回 True，但 int() 解析不了它们
+    """
     if text and text[0] in CURRENCY_SYMBOLS:
         text = text[1:].lstrip()
-    if not NUMBER.match(text):
+    # 最常见的纯数字不用正则
+    plain = text.isdecimal()
+    if not plain and not NUMBER.match(text):
         return None
     digits = text.lstrip("+-")
-    if len(digits) > 1 and digits[0] == "0" and digits[1].isdigit():
+    if len(digits) > 1 and digits[0] == "0" and digits[1].isdecimal():
         return None
-    if digits.isdigit() and len(digits) >= MIN_ID_DIGITS:
+    if digits.isdecimal() and len(digits) >= MIN_ID_DIGITS:
         return None
-    text = text.replace(",", "")
-    if INTEGER.match(text):
+    if plain:
         return int(text)
-    return float(text)
+    text = text.replace(",", "")
+    return int(text) if INTEGER.match(text) else float(text)
 
 
 def parse_datetime(text: str) -> date | datetime | None:
-    if len(text) < 6 or not text[:4].isdigit():
+    if len(text) < 6 or not text[:4].isdecimal():
         return None
     # 标准 ISO 写法先用 fromisoformat，比 strptime 快一个数量级
     if ":" in text:
@@ -307,6 +297,9 @@ def parse_datetime(text: str) -> date | datetime | None:
 
 
 def as_text(value: Any) -> str:
+    """单元格转成文本：列名、保留为文本的值、警告里引用的内容都用它；Excel 里年份等数字读出来是 2025.0"""
+    if value is None:
+        return ""
     if isinstance(value, str):
         return value.strip()
     if isinstance(value, bool):
@@ -318,7 +311,8 @@ def as_text(value: Any) -> str:
     if isinstance(value, (date, time)):
         return value.isoformat()
     if isinstance(value, (dict, list)):
-        return json.dumps(value, ensure_ascii=False)
+        # Parquet 的嵌套值里可能有日期、Decimal、bytes，JSON 表示不了的写成字符串
+        return json.dumps(value, ensure_ascii=False, default=str)
     return str(value)
 
 
diff --git a/app/datafiles/detect.py b/app/datafiles/detect.py
index 163825d..27f4215 100644
--- a/app/datafiles/detect.py
+++ b/app/datafiles/detect.py
@@ -3,6 +3,7 @@
 import codecs
 import csv
 import json
+import re
 import zipfile
 from dataclasses import dataclass
 from pathlib import Path
@@ -29,6 +30,10 @@ DELIMITERS = (",", "\t", ";", "|")
 # 判断分隔符只看开头这么多行
 SNIFF_LINES = 50
 
+# 开头像 JSON 才按 JSON 处理：对象的 { 后面只能是 " 或 }，数组的 [ 后面是一个值的开头；
+# CSV 的列名也可能以 [ 开头，例如 [日期],[销售额]
+JSON_START = re.compile(r'\{\s*["}]|\[\s*(?:[\[{"\]\d-]|(?:true|false|null)\s*[,\]])')
+
 
 @dataclass(frozen=True)
 class Detected:
@@ -56,7 +61,7 @@ def detect(path: Path) -> Detected:
     stripped = text.lstrip()
     if not stripped:
         raise DataFileError(422, "文件是空的")
-    if stripped[0] in "[{":
+    if JSON_START.match(stripped):
         return _json_format(text, encoding)
     delimiter = sniff_delimiter(text)
     return Detected("tsv" if delimiter == "\t" else "csv", encoding, text, delimiter)
@@ -115,7 +120,7 @@ def _json_format(text: str, encoding: str) -> Detected:
             return Detected("jsonl", encoding, text)
     except ValueError:
         pass
-    # 以 [ 或 { 开头却不是合法 JSON，按 JSON 报错比当成 CSV 解析出一堆乱码更有用
+    # 开头像 JSON 却不是合法 JSON，按 JSON 报错比当成 CSV 解析出一堆乱码更有用
     line = getattr(json_error, "lineno", None)
     position = f"第 {line} 行" if line else ""
     raise DataFileError(
diff --git a/app/datafiles/insights.py b/app/datafiles/insights.py
index 1bd5105..715e90f 100644
--- a/app/datafiles/insights.py
+++ b/app/datafiles/insights.py
@@ -9,7 +9,6 @@ import json
 from collections.abc import Awaitable, Callable
 from pathlib import Path
 
-import duckdb
 from langchain_core.exceptions import OutputParserException
 from langchain_core.messages import HumanMessage, SystemMessage
 from loguru import logger
@@ -18,9 +17,9 @@ from pydantic import BaseModel, Field, ValidationError
 from app.clients.llm import get_llm
 from app.config import settings
 from app.core.exceptions import BizException
-from app.datafiles.aggregate import build_aggregate_sql
-from app.datafiles.query import QueryError, run_query
-from app.datafiles.storage import file_dir
+from app.datafiles.aggregate import run_aggregate
+from app.datafiles.query import QueryError
+from app.datafiles.storage import table_path
 from app.prompt.insights import INSIGHTS_SYSTEM_PROMPT
 from app.schemas.data_file import (
     MAX_SUGGESTIONS,
@@ -106,21 +105,16 @@ def build_input(record: DataFileRecord) -> dict:
 
 
 def _table_input(table: DataTable) -> dict:
-    columns = table.profile.get("columns", [])[:MAX_COLUMNS]
-    keep = {column["name"] for column in columns}
-    positions = [
-        position for position, column in enumerate(table.columns) if column.name in keep
-    ]
     return {
         "table": table.table,
         "label": table.label,
         "rows": table.rows,
-        "columns": columns,
-        # 样例行只保留上面那些列，顺序与 columns 一致
-        "sample": [
-            [row[position] for position in positions]
-            for row in table.profile.get("sample", [])
+        "columns": [
+            column.model_dump(mode="json", exclude_none=True)
+            for column in table.profile.columns[:MAX_COLUMNS]
         ],
+        # 样例行和 columns 都按表的列顺序排列，截掉同样的列
+        "sample": [row[:MAX_COLUMNS] for row in table.profile.sample],
     }
 
 
@@ -140,7 +134,7 @@ def check_draft(
         if not title or table is None or key in seen:
             continue
         if not _fits_chart(item) or not _runs(
-            item, table, file_dir(root, record.file_id)
+            item, table, table_path(root, record.file_id, table)
         ):
             logger.info("丢弃不可用的图表推荐：{} {}", record.file_id, item.title)
             continue
@@ -162,20 +156,11 @@ def _fits_chart(item: ChartSuggestion) -> bool:
     return len(request.metrics) == 1 or item.chart not in ("pie", "funnel")
 
 
-def _runs(item: ChartSuggestion, table: DataTable, directory: Path) -> bool:
-    """真实跑一遍汇总：能编译、能执行，并且有足够的行数画图"""
-    path = directory / table.parquet
-    if not path.is_file():
-        return False
+def _runs(item: ChartSuggestion, table: DataTable, path: Path) -> bool:
+    """真实跑一遍汇总：能编译、能执行（文件已被删除也算不能），并且有足够的行数画图"""
     try:
-        sql, _ = build_aggregate_sql(item.request, table.columns)
-        result = run_query(
-            sql,
-            {"t": path},
-            timeout=settings.data_query_timeout,
-            max_rows=item.request.limit,
-        )
-    except (BizException, QueryError, duckdb.Error):
+        result = run_aggregate(path, item.request, table.columns)
+    except (BizException, QueryError):
         return False
     return len(result.rows) >= MIN_RESULT_ROWS
 
diff --git a/app/datafiles/parse.py b/app/datafiles/parse.py
index 25f583f..3decf5a 100644
--- a/app/datafiles/parse.py
+++ b/app/datafiles/parse.py
@@ -3,7 +3,6 @@
 只读写本地文件，不碰数据库；上传流程在子进程里调用（worker.py），超时直接终止子进程
 """
 
-from dataclasses import dataclass
 from pathlib import Path
 from typing import Any
 
@@ -29,7 +28,7 @@ from app.datafiles.readers import (
     read_parquet,
 )
 from app.datafiles.tables import split_tables
-from app.schemas.data_file import DataColumn, DataFormat, ParseWarning
+from app.schemas.data_file import DataColumn, DataFormat, ParseWarning, TableProfile
 
 
 # 子进程把解析结果转成 JSON 交回上传流程，所以用 pydantic 模型
@@ -39,8 +38,9 @@ class ParsedTable(BaseModel):
     part: int | None
     rows: int
     columns: list[DataColumn]
-    path: Path
-    profile: dict[str, Any]
+    # out_dir 下的 Parquet 文件名
+    parquet: str
+    profile: TableProfile
     preview: list[list[Any]]
     warnings: list[ParseWarning]
 
@@ -53,40 +53,53 @@ class ParsedFile(BaseModel):
     warnings: list[ParseWarning]
 
 
-@dataclass
-class _Built:
-    sheet: str | None
-    part: int | None
-    typed: TypedColumns
-    warnings: list[ParseWarning]
-
-
 def parse_file(path: Path, out_dir: Path) -> ParsedFile:
-    """解析 path，Parquet 写到 out_dir/1.parquet、2.parquet……"""
+    """解析 path，每张表在 out_dir 下写一个 Parquet：1.parquet、2.parquet……"""
     detected = detect(path)
+    out_dir.mkdir(parents=True, exist_ok=True)
     warnings: list[ParseWarning] = []
-    built: list[_Built] = []
+    tables: list[ParsedTable] = []
+
+    def add_table(
+        sheet: str | None,
+        part: int | None,
+        typed: TypedColumns,
+        table_warnings: list[ParseWarning],
+    ) -> None:
+        target = out_dir / f"{len(tables) + 1}.parquet"
+        pq.write_table(typed.table, target)
+        profile, preview = profile_table(target, typed.columns, typed.notes)
+        tables.append(
+            ParsedTable(
+                sheet=sheet,
+                part=part,
+                rows=typed.table.num_rows,
+                columns=typed.columns,
+                parquet=target.name,
+                profile=profile,
+                preview=preview,
+                warnings=table_warnings,
+            )
+        )
 
     def add_grid(grid: Grid) -> None:
-        tables, dropped = split_tables(grid)
+        found, dropped = split_tables(grid)
         warnings.extend(dropped)
-        for table in tables:
+        for table in found:
             names, renamed = clean_names(table.header, table.sheet)
             typed, kept = build_columns(names, list(zip(*table.rows)), table.sheet)
-            built.append(
-                _Built(
-                    table.sheet,
-                    table.part,
-                    typed,
-                    [*table.warnings, *_present(renamed, kept)],
-                )
+            add_table(
+                table.sheet,
+                table.part,
+                typed,
+                [*table.warnings, *_present(renamed, kept)],
             )
 
     def add_records(records: Records) -> None:
         warnings.extend(records.warnings)
         names, renamed = clean_names(records.names, None)
         typed, kept = build_columns(names, records.columns, None)
-        built.append(_Built(None, None, typed, _present(renamed, kept)))
+        add_table(None, None, typed, _present(renamed, kept))
 
     match detected.format:
         case "csv" | "tsv":
@@ -107,28 +120,10 @@ def parse_file(path: Path, out_dir: Path) -> ParsedFile:
         case "parquet":
             typed, renamed = arrow_columns(read_parquet(path))
             if typed.table.num_rows:
-                built.append(_Built(None, None, typed, _present(renamed)))
+                add_table(None, None, typed, _present(renamed))
 
-    if not built:
+    if not tables:
         raise DataFileError(422, "文件里没有找到数据")
-    out_dir.mkdir(parents=True, exist_ok=True)
-    tables = []
-    for index, item in enumerate(built, start=1):
-        target = out_dir / f"{index}.parquet"
-        pq.write_table(item.typed.table, target)
-        profile, preview = profile_table(target, item.typed.columns, item.typed.notes)
-        tables.append(
-            ParsedTable(
-                sheet=item.sheet,
-                part=item.part,
-                rows=item.typed.table.num_rows,
-                columns=item.typed.columns,
-                path=target,
-                profile=profile,
-                preview=preview,
-                warnings=item.warnings,
-            )
-        )
     return ParsedFile(
         format=detected.format,
         encoding=detected.encoding,
diff --git a/app/datafiles/profile.py b/app/datafiles/profile.py
index 3e59ca7..6ef2eef 100644
--- a/app/datafiles/profile.py
+++ b/app/datafiles/profile.py
@@ -1,4 +1,4 @@
-"""列概况和预览：上传时在 Parquet 上用 DuckDB 计算，存进文件记录，供 describe_data 和接口返回"""
+"""列概况和预览：上传时在 Parquet 上用 DuckDB 计算，存进文件记录，供 describe_data、上传后的分析和接口返回"""
 
 import math
 from pathlib import Path
@@ -6,8 +6,9 @@ from typing import Any
 
 import duckdb
 
+from app.datafiles.columns import EXACT_FLOAT_INT
 from app.datafiles.query import connect, json_value, quote_identifier
-from app.schemas.data_file import DataColumn
+from app.schemas.data_file import ColumnProfile, DataColumn, TableProfile, TopValue
 
 PREVIEW_ROWS = 20
 SAMPLE_ROWS = 5
@@ -23,11 +24,10 @@ PREVIEW_CELL_CHARS = 200
 
 def profile_table(
     path: Path, columns: list[DataColumn], notes: dict[str, str]
-) -> tuple[dict[str, Any], list[list[Any]]]:
+) -> tuple[TableProfile, list[list[Any]]]:
     """返回列概况和接口用的预览（前 PREVIEW_ROWS 行）"""
     connection = connect({"t": path})
     try:
-        rows = connection.execute("SELECT count(*) FROM t").fetchone()[0]
         connection.execute("SUMMARIZE t")
         fields = [column[0] for column in connection.description]
         summary = {row[0]: dict(zip(fields, row)) for row in connection.fetchall()}
@@ -48,13 +48,12 @@ def profile_table(
         ).fetchall()
     finally:
         connection.close()
-    profile = {
-        "rows": rows,
-        "columns": profiled,
-        "sample": [
+    profile = TableProfile(
+        columns=profiled,
+        sample=[
             [json_value(value, PROFILE_CELL_CHARS) for value in row] for row in sample
         ],
-    }
+    )
     preview = [
         [json_value(value, PREVIEW_CELL_CHARS) for value in row]
         for row in head[:PREVIEW_ROWS]
@@ -92,25 +91,19 @@ def _profile_column(
     head: list[tuple],
     position: int,
     note: str | None,
-) -> dict[str, Any]:
-    item: dict[str, Any] = {"name": column.name, "type": column.type}
-    if column.format:
-        item["format"] = column.format
-    null_ratio = float(stats["null_percentage"]) / 100
-    item["null_ratio"] = round(null_ratio, 4)
-    # approx_unique 是估算值，小表上可能比行数还大
-    item["distinct"] = min(
-        stats["approx_unique"], round(stats["count"] * (1 - null_ratio))
-    )
+) -> ColumnProfile:
+    item: dict[str, Any] = {}
     if column.type == "number":
-        for key in ("min", "max", "avg", "q25", "q50", "q75"):
-            item[key] = _number(stats[key])
+        item = {
+            key: _number(stats[key])
+            for key in ("min", "max", "avg", "q25", "q50", "q75")
+        }
     elif column.type in ("date", "datetime"):
         # SUMMARIZE 的时间用空格分隔，和预览里的 ISO 写法统一
-        item["min"], item["max"] = (
-            None if stats[key] is None else stats[key].replace(" ", "T", 1)
+        item = {
+            key: None if stats[key] is None else stats[key].replace(" ", "T", 1)
             for key in ("min", "max")
-        )
+        }
     if (
         column.type in ("text", "boolean")
         and stats["approx_unique"] <= TOP_VALUES_MAX_DISTINCT
@@ -121,7 +114,7 @@ def _profile_column(
             f"GROUP BY 1 ORDER BY n DESC, 1 LIMIT {TOP_VALUES}"
         ).fetchall()
         item["top_values"] = [
-            {"value": json_value(value, PROFILE_CELL_CHARS), "count": count}
+            TopValue(value=json_value(value, PROFILE_CELL_CHARS), count=count)
             for value, count in counts
         ]
     examples: list[Any] = []
@@ -131,10 +124,16 @@ def _profile_column(
             examples.append(value)
             if len(examples) == EXAMPLES:
                 break
-    item["examples"] = examples
-    if note:
-        item["note"] = note
-    return item
+    null_ratio = float(stats["null_percentage"]) / 100
+    return ColumnProfile(
+        **column.model_dump(),
+        null_ratio=round(null_ratio, 4),
+        # approx_unique 是估算值，小表上可能比行数还大
+        distinct=min(stats["approx_unique"], round(stats["count"] * (1 - null_ratio))),
+        examples=examples,
+        note=note,
+        **item,
+    )
 
 
 def _number(text: str | None) -> int | float | None:
@@ -144,6 +143,6 @@ def _number(text: str | None) -> int | float | None:
     value = float(text)
     if not math.isfinite(value):
         return None
-    if value.is_integer() and abs(value) < 2**53:
+    if value.is_integer() and abs(value) < EXACT_FLOAT_INT:
         return int(value)
     return round(value, 6)
diff --git a/app/datafiles/readers.py b/app/datafiles/readers.py
index cb8bc22..f3d1835 100644
--- a/app/datafiles/readers.py
+++ b/app/datafiles/readers.py
@@ -19,7 +19,8 @@ from python_calamine import (
     SheetVisibleEnum,
 )
 
-from app.datafiles.base import MAX_TABLE_ROWS, DataFileError, rows_exceeded
+from app.datafiles.base import MAX_TABLE_ROWS, DataFileError, brief, rows_exceeded
+from app.datafiles.columns import as_text
 from app.schemas.data_file import ParseWarning
 
 # 原始网格比数据多出的标题、表头、空行，读取时先粗略拦住明显超限的文件，精确的行数在拆表后检查
@@ -153,7 +154,7 @@ def read_jsonl(text: str) -> Records:
         result.warnings.append(
             ParseWarning(
                 code="bad_lines_skipped",
-                message=f"跳过了 {len(bad)} 行无法解析的内容：{_line_list(bad)}",
+                message=f"跳过了 {len(bad)} 行无法解析的内容：{brief([f'第 {n} 行' for n in bad])}",
             )
         )
     return result
@@ -230,11 +231,5 @@ def _flatten(record: dict, prefix: str, level: int, out: dict[str, Any]) -> None
 
 
 def _scalar(value: Any) -> Any:
-    if isinstance(value, (dict, list)):
-        return json.dumps(value, ensure_ascii=False)
-    return value
-
-
-def _line_list(numbers: list[int]) -> str:
-    shown = "、".join(f"第 {number} 行" for number in numbers[:5])
-    return shown + ("等" if len(numbers) > 5 else "")
+    # 嵌套的对象、数组存成 JSON 字符串，其余原样交给类型推断
+    return as_text(value) if isinstance(value, (dict, list)) else value
diff --git a/app/datafiles/service.py b/app/datafiles/service.py
index eb83828..ed8fff6 100644
--- a/app/datafiles/service.py
+++ b/app/datafiles/service.py
@@ -14,12 +14,11 @@ from pathlib import Path
 from typing import BinaryIO
 from uuid import uuid4
 
-import duckdb
 from loguru import logger
 
 from app.config import PROJECT_ROOT, settings
 from app.core.exceptions import BizException
-from app.datafiles.aggregate import build_aggregate_sql
+from app.datafiles.aggregate import run_aggregate
 from app.datafiles.insights import (
     INSIGHTS_CONCURRENCY,
     INSIGHTS_TIMEOUT,
@@ -27,9 +26,8 @@ from app.datafiles.insights import (
 )
 from app.datafiles.parse import ParsedFile, ParsedTable
 from app.datafiles.profile import read_rows
-from app.datafiles.query import QueryError, run_query
-from app.datafiles.storage import SOURCE_NAME, DataFileStore, file_dir
-from app.schemas.base import JsonObject
+from app.datafiles.query import QueryError
+from app.datafiles.storage import SOURCE_NAME, DataFileStore, table_path
 from app.schemas.data_file import (
     AggregateRequest,
     AggregateResult,
@@ -37,8 +35,6 @@ from app.schemas.data_file import (
     DataTable,
     DataTableRows,
     FileInsights,
-    RequestDataFile,
-    RequestDataTable,
 )
 from app.services.conversation import ConversationStore
 
@@ -75,14 +71,18 @@ class DataFileService:
         self._conversations = conversations
         self._ttl = timedelta(seconds=ttl or settings.data_file_ttl)
         self._parsing = asyncio.Semaphore(PARSE_CONCURRENCY)
-        # 文件数检查、分配表名和写入记录要一起完成，并发上传时才不会超限或重名；单实例部署，进程内的锁就够了
+        # 文件数检查和写入记录要一起完成，并发上传时才不会超限；单实例部署，进程内的锁就够了
         self._saving = asyncio.Lock()
         # 上传后的 LLM 分析；为空表示不分析，文件的 insights 为空
         self._insights = insights
         self._insight_slots = asyncio.Semaphore(INSIGHTS_CONCURRENCY)
-        # 正在本进程里分析的文件。记录里是 pending 却不在这里，说明进程重启过、任务已丢失
+        # 本进程里正在分析的文件，用来拒绝重复的重新分析
         self._analysing: set[str] = set()
         self._tasks: set[asyncio.Task] = set()
+        # 在这之前开始、记录里仍是 pending 的分析属于上一个进程，已随重启丢失；
+        # MongoDB 里的时间只精确到毫秒，这里也截到毫秒，刚启动就开始的分析读回后才不会早于它
+        now = datetime.now(UTC)
+        self._started_at = now.replace(microsecond=now.microsecond // 1000 * 1000)
 
     async def upload(
         self, user_id: int, conversation_id: str, name: str | None, source: BinaryIO
@@ -91,14 +91,16 @@ class DataFileService:
         # 先粗查一次，满了就不必上传和解析；写入前在锁里再查一次
         _check_count(await self.store.find(conversation_id))
         file_id = f"f_{uuid4().hex}"
-        directory = file_dir(self.root, file_id)
+        directory = self.root / file_id
         try:
             size, sha256 = await asyncio.to_thread(self._save, source, directory)
             async with self._parsing:
                 parsed = await _parse(directory)
             async with self._saving:
-                existing = await self.store.find(conversation_id, include_deleted=True)
-                _check_count([record for record in existing if not record.deleted])
+                _check_count(await self.store.find(conversation_id))
+                first_number = await self.store.reserve_table_numbers(
+                    conversation_id, len(parsed.tables)
+                )
                 record = self._record(
                     file_id,
                     user_id,
@@ -107,18 +109,11 @@ class DataFileService:
                     size,
                     sha256,
                     parsed,
-                    _next_table_number(existing),
+                    first_number,
                 )
-                if self._insights is not None:
-                    # 先登记再写入，别的请求读到 pending 时不会把它当成丢失的任务
-                    self._analysing.add(file_id)
-                    record = record.model_copy(
-                        update={"insights": FileInsights(status="pending")}
-                    )
                 await self.store.insert(record)
         except BaseException:
             # 失败的上传不留文件，会话内的文件数不变
-            self._analysing.discard(file_id)
             await asyncio.to_thread(shutil.rmtree, directory, ignore_errors=True)
             raise
         if self._insights is not None:
@@ -137,9 +132,7 @@ class DataFileService:
         await self._check_conversation(conversation_id, user_id)
         records = await self.store.find(conversation_id)
         return [
-            await self._settle(record)
-            for record in records
-            if record.owner_id == user_id
+            self._settle(record) for record in records if record.owner_id == user_id
         ]
 
     async def get_file(self, user_id: int, file_id: str) -> DataFileRecord:
@@ -147,7 +140,7 @@ class DataFileService:
         # 他人的文件与不存在同样返回 404
         if record is None or record.owner_id != user_id:
             raise BizException(404, NOT_FOUND)
-        return await self._settle(record)
+        return self._settle(record)
 
     async def regenerate_insights(self, user_id: int, file_id: str) -> DataFileRecord:
         """重新分析，用于上次失败之后；正在分析时 409"""
@@ -157,7 +150,7 @@ class DataFileService:
         if file_id in self._analysing:
             raise BizException(409, "正在分析，请稍后")
         self._analysing.add(file_id)
-        pending = FileInsights(status="pending")
+        pending = FileInsights(status="pending", started_at=datetime.now(UTC))
         try:
             await self.store.update_insights(file_id, pending)
         except BaseException:
@@ -179,19 +172,12 @@ class DataFileService:
     ) -> DataTableRows:
         """表的一页数据；表或排序列不存在时 404 / 422，文件已被清理时同样 404"""
         record = await self.get_file(user_id, file_id)
-        table = next((item for item in record.tables if item.table == table_name), None)
-        if table is None:
-            raise BizException(404, "数据表不存在")
+        table, path = self._table(record, table_name)
         if sort_by is not None and sort_by not in {c.name for c in table.columns}:
             raise BizException(422, f"排序列不存在：{sort_by}")
-        path = file_dir(self.root, file_id) / table.parquet
-        try:
-            rows = await asyncio.to_thread(
-                read_rows, path, offset, limit, sort_by, descending
-            )
-        except duckdb.IOException:
-            # 记录还在但 Parquet 已被删除（过期清理、删除时目录没删净）
-            raise BizException(404, NOT_FOUND) from None
+        rows = await asyncio.to_thread(
+            read_rows, path, offset, limit, sort_by, descending
+        )
         return DataTableRows(total=table.rows, offset=offset, rows=rows)
 
     async def aggregate(
@@ -199,81 +185,36 @@ class DataFileService:
     ) -> AggregateResult:
         """对一张表分组汇总，供前端做图表数据；和 agent 的 query_data 同一套只读沙箱"""
         record = await self.get_file(user_id, file_id)
-        table = next((item for item in record.tables if item.table == table_name), None)
-        if table is None:
-            raise BizException(404, "数据表不存在")
-        sql, names = build_aggregate_sql(request, table.columns)
-        path = file_dir(self.root, file_id) / table.parquet
-        if not path.is_file():
-            raise BizException(404, NOT_FOUND)
+        table, path = self._table(record, table_name)
         try:
-            result = await asyncio.to_thread(
-                run_query,
-                sql,
-                {"t": path},
-                timeout=settings.data_query_timeout,
-                max_rows=request.limit,
-            )
+            return await asyncio.to_thread(run_aggregate, path, request, table.columns)
         except QueryError as error:
             raise BizException(422, str(error)) from None
-        return AggregateResult(
-            columns=names,
-            rows=[dict(zip(names, row)) for row in result.rows],
-            truncated=result.truncated,
-        )
 
     async def delete_file(self, user_id: int, file_id: str) -> None:
         await self.get_file(user_id, file_id)
         await self.store.mark_deleted(file_id)
         # Windows 上正在查询的 Parquet 删不掉，留给定时清理
-        await asyncio.to_thread(
-            shutil.rmtree, file_dir(self.root, file_id), ignore_errors=True
-        )
+        await asyncio.to_thread(shutil.rmtree, self.root / file_id, ignore_errors=True)
 
     async def request_files(
-        self, user_id: int, conversation_id: str, attachments: list[JsonObject]
-    ) -> list[RequestDataFile]:
-        """本次请求可用的文件，调用方已校验会话归属
+        self, user_id: int, conversation_id: str, attached: set[str]
+    ) -> list[DataFileRecord]:
+        """本次请求可用的文件：当前用户在本会话里未过期的文件，调用方已校验会话归属
 
-        attachments 里 kind 为 data_file 的引用必须是本会话未过期的文件，否则 404；其他种类不处理
+        attached 是本轮附件引用的文件，必须都在其中，否则 404
         """
         records = [
             record
             for record in await self.store.find(conversation_id)
             if record.owner_id == user_id
         ]
-        attached = set()
-        for item in attachments:
-            if item.get("kind") != "data_file":
-                continue
-            if not isinstance(file_id := item.get("file_id"), str):
-                raise BizException(422, "data_file 附件缺少 file_id")
-            attached.add(file_id)
         if attached - {record.file_id for record in records}:
             raise BizException(404, NOT_FOUND)
-        return [
-            RequestDataFile(
-                file_id=record.file_id,
-                name=record.name,
-                attached_this_turn=record.file_id in attached,
-                tables=[
-                    RequestDataTable.model_validate(
-                        {
-                            **table.model_dump(),
-                            "path": str(
-                                file_dir(self.root, record.file_id) / table.parquet
-                            ),
-                        }
-                    )
-                    for table in record.tables
-                ],
-                warnings=record.warnings,
-            )
-            for record in records
-        ]
+        return records
 
     async def aclose(self) -> None:
-        """应用退出时取消还在进行的分析，记录里留下的 pending 下次读取时会记为失败"""
+        """应用退出时取消还在进行的分析，记录里留下的 pending 下次启动后读取时按失败返回"""
         for task in list(self._tasks):
             task.cancel()
         await asyncio.gather(*self._tasks, return_exceptions=True)
@@ -293,6 +234,7 @@ class DataFileService:
             await asyncio.sleep(SWEEP_INTERVAL)
 
     def _start_insights(self, record: DataFileRecord) -> None:
+        self._analysing.add(record.file_id)
         task = asyncio.create_task(self._analyse(record))
         self._tasks.add(task)
         task.add_done_callback(self._tasks.discard)
@@ -323,18 +265,32 @@ class DataFileService:
         finally:
             self._analysing.discard(record.file_id)
 
-    async def _settle(self, record: DataFileRecord) -> DataFileRecord:
-        """pending 但本进程没有在分析（重启丢了任务），记为失败，免得前端一直等"""
+    def _settle(self, record: DataFileRecord) -> DataFileRecord:
+        """服务启动前开始、仍是 pending 的分析已随重启丢失，按失败返回，免得前端一直等
+
+        只看记录本身，不写回存储：读到的记录可能已经过时，写回会覆盖刚完成的结果
+        """
         insights = record.insights
         if (
-            insights is None
-            or insights.status != "pending"
-            or record.file_id in self._analysing
+            insights is not None
+            and insights.status == "pending"
+            and (insights.started_at is None or insights.started_at < self._started_at)
         ):
-            return record
-        failed = FileInsights(status="failed")
-        await self.store.update_insights(record.file_id, failed)
-        return record.model_copy(update={"insights": failed})
+            return record.model_copy(update={"insights": FileInsights(status="failed")})
+        return record
+
+    def _table(self, record: DataFileRecord, name: str) -> tuple[DataTable, Path]:
+        """文件里的一张表和它的 Parquet
+
+        表不存在，或 Parquet 已被删除（删除时目录没删净、过期清理）时 404
+        """
+        table = next((item for item in record.tables if item.table == name), None)
+        if table is None:
+            raise BizException(404, "数据表不存在")
+        path = table_path(self.root, record.file_id, table)
+        if not path.is_file():
+            raise BizException(404, NOT_FOUND)
+        return table, path
 
     async def _check_conversation(self, conversation_id: str, user_id: int) -> None:
         if not await self._conversations.exists(conversation_id, user_id):
@@ -348,7 +304,7 @@ class DataFileService:
             while chunk := source.read(CHUNK_BYTES):
                 size += len(chunk)
                 if size > self.max_mb * 1024 * 1024:
-                    raise BizException(413, f"文件不能超过 {self.max_mb} MB")
+                    raise file_too_large(self.max_mb)
                 digest.update(chunk)
                 target.write(chunk)
         return size, digest.hexdigest()
@@ -371,12 +327,7 @@ class DataFileService:
                 DataTable(
                     table=table_name,
                     label=_label(name, table),
-                    sheet=table.sheet,
-                    rows=table.rows,
-                    columns=table.columns,
-                    preview=table.preview,
-                    profile=table.profile,
-                    parquet=table.path.name,
+                    **table.model_dump(exclude={"part", "warnings"}),
                 )
             )
             warnings.extend(
@@ -397,6 +348,11 @@ class DataFileService:
             expires_at=now + self._ttl,
             tables=tables,
             warnings=warnings,
+            insights=(
+                None
+                if self._insights is None
+                else FileInsights(status="pending", started_at=now)
+            ),
         )
 
     def _remove_orphans(self, live: set[str]) -> int:
@@ -466,6 +422,10 @@ def _python() -> tuple[str, dict[str, str] | None]:
     return sys.executable, None
 
 
+def file_too_large(max_mb: int) -> BizException:
+    return BizException(413, f"文件不能超过 {max_mb} MB")
+
+
 def _check_count(records: list[DataFileRecord]) -> None:
     if len(records) >= MAX_FILES_PER_CONVERSATION:
         raise BizException(
@@ -473,12 +433,6 @@ def _check_count(records: list[DataFileRecord]) -> None:
         )
 
 
-def _next_table_number(records: list[DataFileRecord]) -> int:
-    """表名在会话内递增，已删除文件的表名也不再使用"""
-    used = (int(table.table[1:]) for record in records for table in record.tables)
-    return max(used, default=0) + 1
-
-
 def _clean_name(name: str | None) -> str:
     # 有的浏览器会带上本地路径，只保留文件名
     base = re.split(r"[\\/]", name or "")[-1].strip()
diff --git a/app/datafiles/storage.py b/app/datafiles/storage.py
index c5d83a3..568880e 100644
--- a/app/datafiles/storage.py
+++ b/app/datafiles/storage.py
@@ -2,6 +2,7 @@
 
 目录结构是 DATA_FILE_DIR/<file_id>/，里面有原文件 source 和每张表的 1.parquet、2.parquet……
 DuckDB 只能读本地文件，所以文件不进 MongoDB；单实例部署，本地磁盘就够了
+会话内的表名 t1、t2……由每个会话一个的计数器分配，文件删除、过期后表名也不再使用
 """
 
 from datetime import UTC, datetime
@@ -9,16 +10,16 @@ from pathlib import Path
 from typing import Any, Protocol
 
 from bson.codec_options import CodecOptions
-from pymongo import ASCENDING
+from pymongo import ASCENDING, ReturnDocument
 
-from app.schemas.data_file import DataFileRecord, FileInsights
+from app.schemas.data_file import DataFileRecord, DataTable, FileInsights
 
 # 原文件不带扩展名：calamine 见到 .xls 等扩展名会按扩展名打开，用户的扩展名和内容不符时会失败
 SOURCE_NAME = "source"
 
 
-def file_dir(root: Path, file_id: str) -> Path:
-    return root / file_id
+def table_path(root: Path, file_id: str, table: DataTable) -> Path:
+    return root / file_id / table.parquet
 
 
 def _now() -> datetime:
@@ -34,10 +35,12 @@ class DataFileStore(Protocol):
         """未过期且未删除的记录"""
         ...
 
-    async def find(
-        self, conversation_id: str, *, include_deleted: bool = False
-    ) -> list[DataFileRecord]:
-        """会话内未过期的记录，按上传时间排列"""
+    async def find(self, conversation_id: str) -> list[DataFileRecord]:
+        """会话内未过期且未删除的记录，按上传时间排列"""
+        ...
+
+    async def reserve_table_numbers(self, conversation_id: str, count: int) -> int:
+        """为会话预留 count 个连续的表号，返回第一个；表号从 1 开始，不会重复分配"""
         ...
 
     async def mark_deleted(self, file_id: str) -> None: ...
@@ -54,6 +57,8 @@ class DataFileStore(Protocol):
 class InMemoryDataFileStore:
     def __init__(self) -> None:
         self._records: dict[str, DataFileRecord] = {}
+        # 会话 → 已分配的最大表号
+        self._table_numbers: dict[str, int] = {}
 
     def _purge_expired(self) -> None:
         now = _now()
@@ -71,18 +76,20 @@ class InMemoryDataFileStore:
         record = self._records.get(file_id)
         return None if record is None or record.deleted else record
 
-    async def find(
-        self, conversation_id: str, *, include_deleted: bool = False
-    ) -> list[DataFileRecord]:
+    async def find(self, conversation_id: str) -> list[DataFileRecord]:
         self._purge_expired()
         records = [
             record
             for record in self._records.values()
-            if record.conversation_id == conversation_id
-            and (include_deleted or not record.deleted)
+            if record.conversation_id == conversation_id and not record.deleted
         ]
         return sorted(records, key=lambda record: record.created_at)
 
+    async def reserve_table_numbers(self, conversation_id: str, count: int) -> int:
+        first = self._table_numbers.get(conversation_id, 0) + 1
+        self._table_numbers[conversation_id] = first + count - 1
+        return first
+
     async def mark_deleted(self, file_id: str) -> None:
         if (record := self._records.get(file_id)) is not None:
             self._records[file_id] = record.model_copy(update={"deleted": True})
@@ -101,6 +108,8 @@ class MongoDataFileStore:
         # 读回的时间统一带 UTC 时区；集合名前缀用于测试隔离
         options = CodecOptions(tz_aware=True, tzinfo=UTC)
         self._files = db.get_collection(f"{prefix}data_files", codec_options=options)
+        # 每个会话一条：_id 是会话 ID，tables 是已分配的最大表号；会话一直保留，计数器也不过期
+        self._table_numbers = db.get_collection(f"{prefix}data_file_table_numbers")
 
     async def ensure_indexes(self) -> None:
         # 过期记录由 TTL 索引删除；TTL 每分钟才扫一次，查询时仍按 expires_at 过滤
@@ -118,15 +127,12 @@ class MongoDataFileStore:
         )
         return None if document is None else _record(document)
 
-    async def find(
-        self, conversation_id: str, *, include_deleted: bool = False
-    ) -> list[DataFileRecord]:
-        query: dict[str, Any] = {
+    async def find(self, conversation_id: str) -> list[DataFileRecord]:
+        query = {
             "conversation_id": conversation_id,
+            "deleted": False,
             "expires_at": {"$gt": _now()},
         }
-        if not include_deleted:
-            query["deleted"] = False
         documents = await (
             self._files.find(query)
             .sort([("created_at", ASCENDING), ("_id", ASCENDING)])
@@ -134,6 +140,15 @@ class MongoDataFileStore:
         )
         return [_record(document) for document in documents]
 
+    async def reserve_table_numbers(self, conversation_id: str, count: int) -> int:
+        document = await self._table_numbers.find_one_and_update(
+            {"_id": conversation_id},
+            {"$inc": {"tables": count}},
+            upsert=True,
+            return_document=ReturnDocument.AFTER,
+        )
+        return document["tables"] - count + 1
+
     async def mark_deleted(self, file_id: str) -> None:
         await self._files.update_one({"_id": file_id}, {"$set": {"deleted": True}})
 
diff --git a/app/datafiles/tables.py b/app/datafiles/tables.py
index 25caf5b..3ea1d4b 100644
--- a/app/datafiles/tables.py
+++ b/app/datafiles/tables.py
@@ -8,8 +8,8 @@ import re
 from dataclasses import dataclass, field
 from typing import Any
 
-from app.datafiles.base import MAX_TABLE_ROWS, rows_exceeded, where
-from app.datafiles.columns import classify, label_text
+from app.datafiles.base import MAX_TABLE_ROWS, brief, rows_exceeded, where
+from app.datafiles.columns import as_text, classify
 from app.datafiles.readers import Grid
 from app.schemas.data_file import ParseWarning
 
@@ -209,9 +209,7 @@ def _finish(rows: list[list[Any]], piece: _Piece, sheet: str | None) -> RawTable
     totals = [index for index, row in data if _is_total(row)]
     if totals:
         data = [(index, row) for index, row in data if not _is_total(row)]
-        listed = "、".join(str(index + 1) for index in totals[:5]) + (
-            "等" if len(totals) > 5 else ""
-        )
+        listed = brief([str(index + 1) for index in totals])
         warnings.append(
             ParseWarning(
                 code="total_rows_removed",
@@ -250,7 +248,7 @@ def _merge_header(top: list[Any], sub: list[Any]) -> list[str]:
     for upper, lower in zip(top, sub):
         if upper is not None:
             carry = upper
-        parts = [label_text(part) for part in (carry, lower) if part is not None]
+        parts = [as_text(part) for part in (carry, lower) if part is not None]
         merged.append("-".join(parts))
     return merged
 
@@ -280,7 +278,7 @@ def _quote(row: list[Any]) -> str:
     value = next((value for value in row if value is not None), None)
     if value is None:
         return ""
-    text = label_text(value)
+    text = as_text(value)
     if len(text) > QUOTE_CHARS:
         text = text[:QUOTE_CHARS] + "…"
     return f"「{text}」"
diff --git a/app/main.py b/app/main.py
index b5daa01..38e4040 100644
--- a/app/main.py
+++ b/app/main.py
@@ -8,6 +8,7 @@ from loguru import logger
 
 from app.api.agent import router
 from app.api.conversations import router as conversation_router
+from app.api.files import UploadSizeLimit
 from app.api.files import limits_router as file_limits_router
 from app.api.files import router as file_router
 from app.api.materials import router as material_router
@@ -98,6 +99,8 @@ def create_app() -> FastAPI:
     # 上传限制无需登录；要先于 /files/{file_id} 注册，否则会被当成文件 ID
     application.include_router(file_limits_router, prefix="/api")
     application.include_router(file_router, prefix="/api", dependencies=authenticated)
+    # 上传在读请求体之前先按 Content-Length 检查大小
+    application.add_middleware(UploadSizeLimit, path=f"/api{file_router.prefix}")
     application.include_router(material_router, prefix="/api")
     return application
 
diff --git a/app/observability/tracing.py b/app/observability/tracing.py
index 113e34b..00118d4 100644
--- a/app/observability/tracing.py
+++ b/app/observability/tracing.py
@@ -55,14 +55,21 @@ def flush_tracing() -> None:
         logger.opt(exception=exc).warning("Langfuse flush 失败")
 
 
-async def astream_screen(graph, payload, *, thread_id, session_id=None, user_id=None):
-    """同一轮流保持同一个追踪上下文，关闭流时结束追踪"""
+async def astream_screen(
+    graph, payload, *, thread_id, session_id=None, user_id=None, context=None
+):
+    """同一轮流保持同一个追踪上下文，关闭流时结束追踪；context 是图的运行上下文，不进检查点"""
     from contextlib import aclosing
 
     result = {}
     with _screen_trace(payload, thread_id, session_id, user_id) as (config, root):
         async with aclosing(
-            graph.astream(payload, config=config, stream_mode=["custom", "values"])
+            graph.astream(
+                payload,
+                config=config,
+                context=context,
+                stream_mode=["custom", "values"],
+            )
         ) as events:
             async for mode, data in events:
                 if mode == "values":
diff --git a/app/processor/graph.py b/app/processor/graph.py
index 18372d9..4f5a303 100644
--- a/app/processor/graph.py
+++ b/app/processor/graph.py
@@ -11,7 +11,7 @@ from app.processor.nodes.intent_node import IntentNode
 from app.processor.nodes.qa_node import QANode
 from app.processor.nodes.screen_agent_node import ScreenAgentNode
 from app.processor.nodes.wait_for_user_node import WaitForUserNode
-from app.processor.state import QueryState
+from app.processor.state import QueryState, RunContext
 
 
 def build_checkpoint_serde() -> JsonPlusSerializer:
@@ -47,7 +47,7 @@ def route_after_wait(state: QueryState) -> str:
 
 
 def build_graph(checkpointer=None):
-    workflow = StateGraph(QueryState)
+    workflow = StateGraph(QueryState, context_schema=RunContext)
     nodes = {
         "input_node": InputNode(),
         "intent_node": IntentNode(),
diff --git a/app/processor/nodes/qa_node.py b/app/processor/nodes/qa_node.py
index 56b127c..c52bd6b 100644
--- a/app/processor/nodes/qa_node.py
+++ b/app/processor/nodes/qa_node.py
@@ -10,11 +10,10 @@ from langchain_core.messages import AIMessageChunk, HumanMessage
 from langchain_core.output_parsers import StrOutputParser
 from langgraph.config import get_stream_writer
 
-from app.agent.data_tools import DataContext
 from app.agent.qa_agent import QAContext, get_qa_agent
 from app.processor.base import BaseNode
 from app.processor.history import history_messages
-from app.processor.state import QueryState
+from app.processor.state import QueryState, run_data
 from app.processor.summary import data_file_summary
 
 # 模型在一次回答里分几次输出文字（例如查询前后各说一段）时，段落之间空一行
@@ -56,7 +55,7 @@ class QANode(BaseNode):
                         HumanMessage(content=json.dumps(payload, ensure_ascii=False)),
                     ]
                 },
-                context=QAContext(data=DataContext(tuple(context.data_files))),
+                context=QAContext(data=run_data()),
                 stream_mode="messages",
             ):
                 # 工具结果、工具调用和中间件插入的消息都不推送
diff --git a/app/processor/nodes/screen_agent_node.py b/app/processor/nodes/screen_agent_node.py
index b5b0461..24b9bdc 100644
--- a/app/processor/nodes/screen_agent_node.py
+++ b/app/processor/nodes/screen_agent_node.py
@@ -7,12 +7,11 @@ import json
 
 from langchain_core.messages import HumanMessage
 
-from app.agent.data_tools import DataContext
 from app.agent.screen_agent import AgentReply, get_screen_agent
 from app.agent.tools import ScreenAgentContext
 from app.processor.base import BaseNode
 from app.processor.history import history_messages
-from app.processor.state import QueryState
+from app.processor.state import QueryState, run_data
 from app.processor.summary import request_summary
 from app.resources.component import get_catalog_cache
 
@@ -68,7 +67,7 @@ class ScreenAgentNode(BaseNode):
             context=ScreenAgentContext(
                 screen=context.screen,
                 catalog=catalog,
-                data=DataContext(tuple(context.data_files)),
+                data=run_data(),
             ),
         )
         if result.get("structured_response") is None:
diff --git a/app/processor/state.py b/app/processor/state.py
index 30e35a9..38b6bca 100644
--- a/app/processor/state.py
+++ b/app/processor/state.py
@@ -1,5 +1,9 @@
+from dataclasses import dataclass, field
 from typing import Literal, NotRequired, TypedDict
 
+from langgraph.runtime import get_runtime
+
+from app.agent.data_tools import DataContext
 from app.schemas.actions import Action
 from app.schemas.base import JsonObject
 from app.schemas.clarification import Clarification
@@ -25,3 +29,21 @@ class QueryState(TypedDict):
     status: NotRequired[
         Literal["running", "waiting_for_input", "completed", "cancelled", "failed"]
     ]  # 后端处理、等待补充、处理完成、用户取消或失败，完成不代表前端已执行
+
+
+@dataclass(frozen=True)
+class RunContext:
+    """图的运行上下文：本次运行要用、但不进检查点的依赖，每次启动和恢复时由调用方传入"""
+
+    # 本会话的数据文件；状态里的 input_context.data_files 只有摘要，列概况和路径在这里
+    data: DataContext = field(default_factory=DataContext)
+
+
+def run_data() -> DataContext:
+    """当前运行可用的数据表；单独调用节点（不在图里执行）或调用方没传 context 时为空"""
+    try:
+        runtime = get_runtime(RunContext)
+    except RuntimeError:
+        return DataContext()
+    context = runtime.context if runtime is not None else None
+    return context.data if context is not None else DataContext()
diff --git a/app/schemas/data_file.py b/app/schemas/data_file.py
index 94884ca..aa839e6 100644
--- a/app/schemas/data_file.py
+++ b/app/schemas/data_file.py
@@ -44,6 +44,41 @@ class ParseWarning(BaseModel):
     message: str
 
 
+class TopValue(BaseModel):
+    value: JsonValue
+    count: int
+
+
+class ColumnProfile(DataColumn):
+    """一列的概况，上传时在全表上算出；不适用的统计为空，交给模型时省略"""
+
+    null_ratio: float
+    # 去重值个数，是估算值
+    distinct: int
+    # 数值列是数字，日期、日期时间列是 ISO 写法的字符串
+    min: int | float | str | None = None
+    max: int | float | str | None = None
+    # 只有数值列有
+    avg: int | float | None = None
+    q25: int | float | None = None
+    q50: int | float | None = None
+    q75: int | float | None = None
+    # 去重值不多的文本、布尔列才有，按出现次数从多到少
+    top_values: list[TopValue] | None = None
+    # 开头几行里不同的取值
+    examples: list[JsonValue]
+    # 保留为文本的原因等说明
+    note: str | None = None
+
+
+class TableProfile(BaseModel):
+    """表的列概况，给 describe_data 和上传后的分析用"""
+
+    columns: list[ColumnProfile]
+    # 随机抽的几行，顺序与 columns 一致
+    sample: list[list[JsonValue]]
+
+
 class DataTableInfo(BaseModel):
     # 会话内的表名 t1、t2……，模型写 SQL 时用
     table: str
@@ -60,8 +95,7 @@ class DataTableDetail(DataTableInfo):
 
 
 class DataTable(DataTableDetail):
-    # 列概况，给 describe_data 用
-    profile: dict[str, JsonValue]
+    profile: TableProfile
     # 文件目录下的 Parquet 文件名
     parquet: str
 
@@ -162,6 +196,8 @@ class FileInsights(BaseModel):
     version: int = 1
     # pending：正在分析；ready：已完成（推荐可能为空）；failed：分析失败，文件本身可用
     status: Literal["pending", "ready", "failed"]
+    # pending 时是开始分析的时间；服务启动前开始、至今仍是 pending 的分析已随重启丢失，读取时按失败返回
+    started_at: datetime | None = None
     summary: str = ""
     suggestions: list[ChartSuggestion] = Field(default_factory=list)
     columns: list[ColumnInsight] = Field(default_factory=list)
@@ -224,19 +260,14 @@ class DataFileLimits(BaseModel):
     aggregate_max_rows: int
 
 
-class RequestDataTable(DataTableInfo):
-    """本次请求可用的表：多出工具要用的列概况和 Parquet 路径，不带预览"""
-
-    profile: dict[str, JsonValue]
-    path: str
-
-
 class RequestDataFile(BaseModel):
-    """本次请求可用的文件：服务端按会话读取后放进请求，前端传的同名字段会被覆盖"""
+    """本次请求可用的文件：服务端按会话读取后放进请求，前端传的同名字段会被覆盖
+
+    请求会进检查点，所以只放表名、行数和列；列概况和文件路径在图的运行上下文里，见 processor/state.py
+    """
 
     file_id: str
     name: str
     # 本轮消息的 attachments 里带了这个文件，通常是刚上传的
     attached_this_turn: bool
-    tables: list[RequestDataTable]
-    warnings: list[ParseWarning]
+    tables: list[DataTableInfo]
diff --git a/app/schemas/request.py b/app/schemas/request.py
index ede87c7..0eaf587 100644
--- a/app/schemas/request.py
+++ b/app/schemas/request.py
@@ -1,6 +1,6 @@
 """前端设计请求：原始需求、当前大屏及可选补充上下文"""
 
-from pydantic import Field
+from pydantic import Field, field_validator
 
 from .base import ExtensibleModel, JsonObject, NonBlankString
 from .screen import Screen
@@ -20,3 +20,22 @@ class DesignRequest(ExtensibleModel):
     # 本条消息附带的材料；{"kind": "data_file", "file_id": "..."} 引用本会话上传的数据文件，
     # 其他种类只原样进入摘要，不读取文件或远程资源
     attachments: list[JsonObject] = Field(default_factory=list)
+
+    @field_validator("attachments")
+    @classmethod
+    def _data_files_have_ids(cls, value: list[JsonObject]) -> list[JsonObject]:
+        for item in value:
+            if item.get("kind") == "data_file" and not isinstance(
+                item.get("file_id"), str
+            ):
+                raise ValueError("data_file 附件缺少 file_id")
+        return value
+
+    @property
+    def data_file_ids(self) -> set[str]:
+        """本条消息附带的数据文件"""
+        return {
+            str(item["file_id"])
+            for item in self.attachments
+            if item.get("kind") == "data_file"
+        }
diff --git a/app/services/agent.py b/app/services/agent.py
index e19f19a..852cb05 100644
--- a/app/services/agent.py
+++ b/app/services/agent.py
@@ -7,13 +7,16 @@ from uuid import uuid4
 from langgraph.types import Command
 from loguru import logger
 
+from app.agent.data_tools import DataContext
 from app.config import settings
 from app.core.exceptions import BizException
 from app.datafiles.service import DataFileService
 from app.observability.tracing import astream_screen
 from app.processor.history import trim_history
+from app.processor.state import RunContext
 from app.schemas.agent import AgentResult, ResumeRequest
 from app.schemas.conversation import Turn
+from app.schemas.data_file import DataFileRecord, RequestDataFile
 from app.schemas.request import DesignRequest
 from app.services.conversation import ConversationStore
 
@@ -43,8 +46,9 @@ class AgentService:
                 conversation_id, settings.conversation_history_turns
             )
             # 附件引用的文件不属于本会话时在流开始前返回 404
-            data_files = await self.data_files.request_files(
-                user_id, conversation_id, request.attachments
+            attached = request.data_file_ids
+            records = await self.data_files.request_files(
+                user_id, conversation_id, attached
             )
         except BaseException:
             self.release(thread_id)
@@ -64,7 +68,16 @@ class AgentService:
             settings.history_max_tokens,
         )
         # 同样只信任服务端读取的结果；会话内的文件每一轮都可用，不附带也能查询
-        payload["data_files"] = [item.model_dump(mode="json") for item in data_files]
+        # 请求会进检查点，只放摘要；工具要用的列概况和路径通过运行上下文传给图
+        payload["data_files"] = [
+            RequestDataFile(
+                file_id=record.file_id,
+                name=record.name,
+                attached_this_turn=record.file_id in attached,
+                tables=record.tables,
+            ).model_dump(mode="json")
+            for record in records
+        ]
 
         return (
             thread_id,
@@ -76,6 +89,7 @@ class AgentService:
             },
             conversation_id,
             user_id,
+            self._run_context(records),
         )
 
     async def prepare_resume(self, request: ResumeRequest, user_id: int):
@@ -117,6 +131,10 @@ class AgentService:
                         )
                     }
                 )
+            # 运行上下文不在检查点里，恢复时按会话重新读取；期间删除或过期的文件工具查不到
+            records = await self.data_files.request_files(
+                user_id, conversation_id, set()
+            )
 
             # 每次有效补充或取消生成新的输入 ID，任务和会话保持不变
             return (
@@ -127,11 +145,15 @@ class AgentService:
                 ),
                 conversation_id,
                 user_id,
+                self._run_context(records),
             )
         except BaseException:
             self.release(thread_id)
             raise
 
+    def _run_context(self, records: list[DataFileRecord]) -> RunContext:
+        return RunContext(data=DataContext(tuple(records), self.data_files.root))
+
     def release(self, thread_id):
         self._active.discard(thread_id)
         self._conversation_of.pop(thread_id, None)
@@ -199,7 +221,7 @@ class AgentService:
             clarification=state.get("clarification") if waiting else None,
         )
 
-    async def stream(self, thread_id, payload, session_id, user_id=None):
+    async def stream(self, thread_id, payload, session_id, user_id=None, context=None):
         """消费图事件，完整状态只用于整理最终结果，不直接暴露给客户端"""
         state = None
         with logger.contextualize(thread_id=thread_id):
@@ -210,6 +232,7 @@ class AgentService:
                     thread_id=thread_id,
                     session_id=session_id,
                     user_id=user_id,
+                    context=context,
                 )
             ) as events:
                 async for mode, data in events: