性能：比价和领券分位数改为 PostgreSQL 聚合 (#161)

## 背景
- 比价记录页和领券记录页前端已经只拉当前页，并直接展示后端 summary。
- 原后端仍会将筛选区间内的全部耗时值取回 Python 计算分位数，生产数据量增大后会放大数据库读取和应用内存开销。

## 修改内容
- 比价记录：成功耗时 P5/P50/P95/P99、平均耗时以及中途退出耗时 P5/P50/P95 改用 PostgreSQL percentile_cont/AVG 聚合。
- 领券记录：发起数、完成数、平均耗时和完成耗时 P5/P50/P95/P99 合并为一条 PostgreSQL 聚合查询。
- 日期、用户、环境、状态、店铺和商品等筛选条件继续与列表共用，统计口径不变。
- SQLite 不支持 percentile_cont，仅在本地和测试环境回退读取耗时单列；不加载完整业务记录。
- API 字段与前端展示保持不变，无需前端改动。

## 验证
- 比价/领券及关联广告收益、点位、按券统计测试：26 passed。
- 本次涉及文件 ruff 检查通过。
- PostgreSQL SQL 编译测试确认使用 ordered-set percentile_cont 聚合。
- 全量测试：497 passed；8 个现有失败集中在邀请奖励、提现档位和代理转发等无关模块。

---------

Co-authored-by: unknown <798648091@qq.com>
Reviewed-on: #161
Co-authored-by: linkeyu <linkeyu@wonderable.ai>
Co-committed-by: linkeyu <linkeyu@wonderable.ai>

tests/test_comparison_admin_summary.py

@@ -4,12 +4,28 @@ from __future__ import annotations
 from datetime import UTC, date, datetime
 
 import pytest
+from sqlalchemy.dialects import postgresql
 
 from app.admin.repositories import queries
 from app.db.session import SessionLocal
 from app.models.comparison import ComparisonRecord
 
 
+def test_postgresql_duration_summary_uses_ordered_set_aggregates() -> None:
+    stmt = queries._comparison_duration_aggregate_stmt(
+        [], "success", (0.05, 0.5, 0.95, 0.99)
+    )
+    sql = str(
+        stmt.compile(
+            dialect=postgresql.dialect(),
+            compile_kwargs={"literal_binds": True},
+        )
+    )
+
+    assert sql.count("percentile_cont") == 4
+    assert "comparison_record.status = 'success'" in sql
+
+
 def test_summary_uses_only_success_durations_and_filters_beijing_date() -> None:
     db = SessionLocal()
     try:

tests/test_coupon_platform_success.py

@@ -7,8 +7,12 @@ from __future__ import annotations
 from datetime import UTC, date, datetime
 
 from sqlalchemy import delete, func, select
+from sqlalchemy.dialects import postgresql
 
-from app.admin.repositories.coupon_data import coupon_data_report
+from app.admin.repositories.coupon_data import (
+    _coupon_summary_aggregate_stmt,
+    coupon_data_report,
+)
 from app.db.session import SessionLocal
 from app.models.coupon_state import CouponSession
 from app.repositories.coupon_state import (
@@ -19,7 +23,12 @@ from app.repositories.coupon_state import (
 
 
 def _agg_session(
-    trace: str, platforms, platform_success, *, status: str = "completed"
+    trace: str,
+    platforms,
+    platform_success,
+    *,
+    status: str = "completed",
+    elapsed_ms: int | None = None,
 ) -> CouponSession:
     """构造一条聚合测试用 session(started_date 固定 2020-01-02、app_env=prod,不 commit)。"""
     return CouponSession(
@@ -31,9 +40,53 @@ def _agg_session(
         platform_success=platform_success,
         started_at=datetime(2020, 1, 2, tzinfo=UTC),
         started_date=date(2020, 1, 2),
+        elapsed_ms=elapsed_ms,
     )
 
 
+def test_postgresql_coupon_summary_uses_ordered_set_aggregates() -> None:
+    sql = str(
+        _coupon_summary_aggregate_stmt([]).compile(
+            dialect=postgresql.dialect(),
+            compile_kwargs={"literal_binds": True},
+        )
+    )
+
+    assert sql.count("percentile_cont") == 4
+    assert "FILTER (WHERE coupon_session.status = 'completed'" in sql
+
+
+def test_coupon_duration_summary_uses_only_completed_rows() -> None:
+    db = SessionLocal()
+    try:
+        db.add_all([
+            _agg_session("duration-a", [], [], elapsed_ms=1000),
+            _agg_session("duration-b", [], [], elapsed_ms=3000),
+            _agg_session(
+                "duration-failed", [], [], status="failed", elapsed_ms=100_000
+            ),
+        ])
+        db.flush()
+
+        summary = coupon_data_report(
+            db,
+            date_from="2020-01-02",
+            date_to="2020-01-02",
+            app_env="prod",
+        )["summary"]
+
+        assert summary["started_count"] == 3
+        assert summary["completed_count"] == 2
+        assert summary["avg_elapsed_ms"] == 2000
+        assert summary["p5_ms"] == 1100
+        assert summary["p50_ms"] == 2000
+        assert summary["p95_ms"] == 2900
+        assert summary["p99_ms"] == 2980
+    finally:
+        db.rollback()
+        db.close()
+
+
 def _make_session(db, trace_id: str, **kw) -> CouponSession:
     row = CouponSession(
         trace_id=trace_id,