perf: 优化 Explore 页数据查询逻辑，修复时间范围与主图末尾日期不一致的问题

Author: sxjeru

CHANGELOG.md

@@ -1,5 +1,12 @@
 # CHANGELOG
 
+## 2026-03-08
+
+- 修复 Explore 页时间范围与主图末尾日期不一致的问题：
+  - 后端探索明细查询移除默认 `limit(50000)` 截断，避免在高频数据下只返回时间范围前段记录、导致主图停在较早日期。
+  - 保留 `maxPoints` 参数能力，仅在显式传入时才限制返回条数。
+  - 前端在 Explore 明细点数超过 `20,000` 时默认关闭散点图开关，优先保证全量时间范围可见，同时降低大数据量下的 SVG 渲染压力。
+
 ## 2026-03-07
 
 - 修复每小时负载分布堆叠图中"输入"与"缓存"重复计数的问题：

app/explore/page.tsx

@@ -57,6 +57,7 @@ const TOKEN_COLORS = {
 
 const CHART_MARGIN = { top: 8, right: 12, left: 8, bottom: 12 };
 const CHART_TOP_INSET = 4;
+const AUTO_HIDE_SCATTER_THRESHOLD = 20_000;
 
 function clamp(num: number, min: number, max: number) {
   return Math.min(Math.max(num, min), max);
@@ -1261,6 +1262,7 @@ export default function ExplorePage() {
           const pointCount = json.points?.length ?? 0;
           // 点数超过 5000 自动启用过滤无效点
           if (pointCount > 5000) setFilterInvalidPoints(true);
+          setShowScatter(pointCount <= AUTO_HIDE_SCATTER_THRESHOLD);
           setAppliedDays(json.days ?? rangeDays);
           setRouteOptions(Array.from(new Set(json.filters?.routes ?? [])));
           setNameOptions(Array.from(new Set(json.filters?.names ?? [])));

lib/queries/explore.ts

@@ -40,8 +40,7 @@ function withDayEnd(date: Date) {
 }
 
 function normalizeMaxPoints(value?: number | null) {
-  const fallback = 50_000;
-  if (value == null || Number.isNaN(value)) return fallback;
+  if (value == null || Number.isNaN(value)) return null;
   return Math.min(Math.max(Math.floor(value), 1_000), 100_000);
 }
 
@@ -138,7 +137,7 @@ export async function getExplorePoints(
 
   // 直接按时间排序查询，不再使用 row_number() 抽样；默认在 SQL 层过滤 tokens=0 的无效点
   const pointsWhere = shouldFilterInvalid ? and(...whereParts, sql`${usageRecords.totalTokens} != 0`) : where;
-  const points: Array<{ ts: number; tokens: number; inputTokens: number; outputTokens: number; reasoningTokens: number; cachedTokens: number; model: string }> = await db
+  let pointsQuery: any = db
     .select({
       ts: sql<number>`(extract(epoch from ${usageRecords.occurredAt}) * 1000)::bigint`,
       tokens: sql<number>`${usageRecords.totalTokens}`,
@@ -150,8 +149,13 @@ export async function getExplorePoints(
     })
     .from(usageRecords)
     .where(pointsWhere)
-    .orderBy(usageRecords.occurredAt)
-    .limit(maxPoints);
+    .orderBy(usageRecords.occurredAt);
+
+  if (maxPoints != null) {
+    pointsQuery = pointsQuery.limit(maxPoints);
+  }
+
+  const points: Array<{ ts: number; tokens: number; inputTokens: number; outputTokens: number; reasoningTokens: number; cachedTokens: number; model: string }> = await pointsQuery;
 
   return {
     days,