diff --git a/src/App.vue b/src/App.vue
index 00180e5..c2ef41e 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -48,7 +48,7 @@
       </div>
     </div>
 
-    <div class="flex-1 overflow-hidden flex">
+    <div class="flex-1 min-h-0 overflow-hidden flex">
       <!-- 左侧文件树侧栏 -->
       <template v-if="sidebarVisible">
         <Sidebar :root-dir="rootDir"
@@ -67,7 +67,7 @@
              @mousedown="startSidebarResize"></div>
       </template>
 
-      <div class="flex-1 overflow-hidden">
+      <div class="flex-1 min-h-0 overflow-hidden">
       <!-- 编辑器代码片段 -->
       <template v-if="showConsole">
         <ResizablePanels :direction="effectiveDirection" :min-primary="minPrimary" :min-secondary="minSecondary">
@@ -90,6 +90,7 @@
                     <span v-if="isDirty" class="ml-1 text-amber-500" title="有未保存的修改">●</span>
                   </span>
                   <SqlSourceSelect v-if="currentLanguage === 'sql'" class="flex-shrink-0"/>
+                  <SchemaBrowser v-if="currentLanguage === 'sql'" class="flex-shrink-0" @preview="previewTable" @insert="insertAtCursor"/>
                 </div>
 
                 <div class="flex items-center space-x-2 text-xs text-gray-500 whitespace-nowrap flex-shrink-0 pl-3">
@@ -117,7 +118,7 @@
 
           <template #secondary>
             <!-- 输出 -->
-            <div class="h-full flex flex-col" :class="effectiveDirection === 'vertical' ? 'border-t border-gray-200' : 'border-l border-gray-200'">
+            <div class="h-full min-h-0 flex flex-col overflow-hidden" :class="effectiveDirection === 'vertical' ? 'border-t border-gray-200' : 'border-l border-gray-200'">
               <!-- 仅编辑器模式下提供收起控制台的入口 -->
               <div v-if="layoutMode === 'editor'" class="bg-gray-100 dark:bg-gray-800 px-4 py-2 border-b border-gray-200 dark:border-gray-700 flex items-center justify-between flex-shrink-0">
                 <h2 class="text-sm font-medium text-gray-700 dark:text-gray-200">控制台</h2>
@@ -127,7 +128,7 @@
               </div>
 
               <ConsoleOutput v-if="consoleType === 'console'"
-                             class="flex-1"
+                             class="flex-1 min-h-0"
                              :output="output"
                              :is-running="isRunning"
                              :is-success="isSuccess"
@@ -137,7 +138,7 @@
 
               <!-- Web输出组件 -->
               <WebOutput v-else-if="consoleType === 'web'"
-                         class="flex-1"
+                         class="flex-1 min-h-0"
                          :web-content="output"
                          :is-running="isRunning"
                          :execution-time="lastExecutionTime"
@@ -146,7 +147,7 @@
 
               <!-- JSON 视图 -->
               <JsonView v-else-if="consoleType === 'json'"
-                        class="flex-1"
+                        class="flex-1 min-h-0"
                         :output="output"
                         :is-running="isRunning"
                         :execution-time="lastExecutionTime"
@@ -154,7 +155,7 @@
 
               <!-- Markdown 预览 -->
               <MarkdownView v-else-if="consoleType === 'markdown'"
-                            class="flex-1"
+                            class="flex-1 min-h-0"
                             :output="output"
                             :is-running="isRunning"
                             :execution-time="lastExecutionTime"
@@ -162,7 +163,7 @@
 
               <!-- XML 视图 -->
               <XmlView v-else-if="consoleType === 'xml'"
-                       class="flex-1"
+                       class="flex-1 min-h-0"
                        :output="output"
                        :is-running="isRunning"
                        :execution-time="lastExecutionTime"
@@ -170,7 +171,7 @@
 
               <!-- YAML 视图 -->
               <YamlView v-else-if="consoleType === 'yaml'"
-                        class="flex-1"
+                        class="flex-1 min-h-0"
                         :output="output"
                         :is-running="isRunning"
                         :execution-time="lastExecutionTime"
@@ -178,7 +179,7 @@
 
               <!-- SQL 表格 -->
               <SqlTableView v-else-if="consoleType === 'sqltable'"
-                            class="flex-1"
+                            class="flex-1 min-h-0"
                             :output="output"
                             :is-running="isRunning"
                             :execution-time="lastExecutionTime"
@@ -186,7 +187,7 @@
 
               <!-- 数据表 / 图表（CSV / TSV） -->
               <DataTableView v-else-if="consoleType === 'table'"
-                             class="flex-1"
+                             class="flex-1 min-h-0"
                              :output="output"
                              :is-running="isRunning"
                              :execution-time="lastExecutionTime"
@@ -215,6 +216,7 @@
               <span v-if="isDirty" class="ml-1 text-amber-500" title="有未保存的修改">●</span>
             </span>
             <SqlSourceSelect v-if="currentLanguage === 'sql'" class="flex-shrink-0"/>
+            <SchemaBrowser v-if="currentLanguage === 'sql'" class="flex-shrink-0" @preview="previewTable" @insert="insertAtCursor"/>
           </div>
 
           <div class="flex items-center space-x-2 text-xs text-gray-500 whitespace-nowrap flex-shrink-0 pl-3">
@@ -245,12 +247,13 @@
          首次打开后保持挂载，用 v-show 收起以保留会话；关闭所有标签才彻底卸载 -->
     <Terminal v-if="terminalMounted"
               v-show="showTerminal"
+              class="flex-shrink-0"
               :root-dir="rootDir"
               @collapse="showTerminal = false"
               @close="showTerminal = false; terminalMounted = false"/>
 
     <!-- 状态栏 -->
-    <StatusBar :env-info="envInfo" :is-loading="isLoadingEnvInfo" :execution-time="lastExecutionTime" :code-length="(code || '').length" @check-environment="refreshEnvInfo" @toggle-terminal="toggleTerminal"/>
+    <StatusBar class="flex-shrink-0" :env-info="envInfo" :is-loading="isLoadingEnvInfo" :execution-time="lastExecutionTime" :code-length="(code || '').length" @check-environment="refreshEnvInfo" @toggle-terminal="toggleTerminal"/>
 
     <!-- 关于组件 -->
     <About v-if="showAbout" @close="closeAbout"/>
@@ -368,6 +371,7 @@ import YamlView from "./components/YamlView.vue";
 import SqlTableView from "./components/SqlTableView.vue";
 import DataTableView from "./components/DataTableView.vue";
 import SqlSourceSelect from "./components/SqlSourceSelect.vue";
+import SchemaBrowser from "./components/SchemaBrowser.vue";
 import StatusBar from './components/StatusBar.vue'
 import About from './components/About.vue'
 import Settings from './components/Settings.vue'
@@ -1341,6 +1345,29 @@ const runSql = async (sqlOverride?: string) => {
   }
 }
 
+// 表结构浏览器：把预览 SQL 写入编辑器并运行（编辑器与运行保持一致）
+const previewTable = (sql: string) => {
+  const view = editorView.value
+  if (view) {
+    view.dispatch({changes: {from: 0, to: view.state.doc.length, insert: sql}})
+  }
+  runSql(sql)
+}
+
+// 表结构浏览器：在光标处插入表名/列名
+const insertAtCursor = (text: string) => {
+  const view = editorView.value
+  if (!view) {
+    return
+  }
+  const {from, to} = view.state.selection.main
+  view.dispatch({
+    changes: {from, to, insert: text},
+    selection: {anchor: from + text.length}
+  })
+  view.focus()
+}
+
 const runSelection = () => {
   const view = editorView.value
   if (!view) {
diff --git a/src/components/DataTableView.vue b/src/components/DataTableView.vue
index b0ed49a..3646e61 100644
--- a/src/components/DataTableView.vue
+++ b/src/components/DataTableView.vue
@@ -5,7 +5,7 @@
       <div class="flex items-center gap-2 text-xs text-gray-500 dark:text-gray-400 min-w-0">
         <Table2 class="w-3.5 h-3.5 flex-shrink-0"/>
         <span>数据表</span>
-        <span v-if="isRunning" class="text-blue-500">解析中…</span>
+        <span v-if="isRunning || parsing" class="text-blue-500">解析中{{ parsing && percent > 0 ? ` ${percent}%` : '' }}…</span>
         <span v-else-if="parsed.rows.length" class="text-gray-400">{{ parsed.columns.length }} 列 · {{ parsed.rows.length }} 行</span>
       </div>
       <div class="flex items-center gap-1">
@@ -28,39 +28,25 @@
     </div>
 
     <!-- 图表视图 -->
-    <div v-if="viewMode === 'chart' && parsed.columns.length" class="flex-1 min-h-0">
+    <div v-if="viewMode === 'chart' && parsed.columns.length" class="flex-1 min-h-0 overflow-hidden">
       <ChartPanel :columns="parsed.columns" :rows="parsed.rows"/>
     </div>
-    <!-- 表格视图 -->
-    <div v-else class="flex-1 overflow-auto p-2 text-xs">
-      <div v-if="!parsed.columns.length" class="text-gray-400 px-2 py-4 text-center">运行后在此查看数据表（支持 CSV / TSV）</div>
-      <div v-else class="overflow-x-auto border border-gray-200 dark:border-gray-700 rounded">
-        <table class="w-full border-collapse">
-          <thead>
-            <tr class="bg-gray-50 dark:bg-gray-800">
-              <th class="text-left font-semibold px-2 py-1.5 border-b border-gray-200 dark:border-gray-700 text-gray-400 w-10">#</th>
-              <th v-for="(c, ci) in parsed.columns" :key="ci" class="text-left font-semibold px-3 py-1.5 border-b border-gray-200 dark:border-gray-700 text-gray-600 dark:text-gray-300 whitespace-nowrap">{{ c }}</th>
-            </tr>
-          </thead>
-          <tbody>
-            <tr v-for="(row, i) in displayRows" :key="i" class="hover:bg-gray-50 dark:hover:bg-gray-800/50">
-              <td class="px-2 py-1 border-b border-gray-100 dark:border-gray-800 text-gray-400">{{ i + 1 }}</td>
-              <td v-for="(_c, ci) in parsed.columns" :key="ci" class="px-3 py-1 border-b border-gray-100 dark:border-gray-800 font-mono whitespace-nowrap text-gray-700 dark:text-gray-300">{{ row[ci] }}</td>
-            </tr>
-          </tbody>
-        </table>
-        <div v-if="parsed.rows.length > displayLimit" class="px-2 py-2 text-center text-gray-400">共 {{ parsed.rows.length }} 行，表格仅显示前 {{ displayLimit }} 行（图表使用全部数据）</div>
-      </div>
+    <!-- 表格视图（虚拟滚动，支持大文件） -->
+    <div v-if="!parsed.columns.length" class="flex-1 overflow-auto p-2 text-xs">
+      <div class="text-gray-400 px-2 py-4 text-center">运行后在此查看数据表（支持 CSV / TSV）</div>
     </div>
+    <VirtualTable v-else class="flex-1" :columns="parsed.columns" :rows="parsed.rows"/>
   </div>
 </template>
 
 <script setup lang="ts">
-import {computed, ref, watch} from 'vue'
+import {onBeforeUnmount, ref, shallowRef, watch} from 'vue'
 import {debounce} from 'lodash-es'
 import {BarChart3, FileDown, Table2, Trash2} from 'lucide-vue-next'
 import ChartPanel from './charts/ChartPanel.vue'
+import VirtualTable from './VirtualTable.vue'
 import {downloadCsv} from '../utils/csv'
+import {type DelimitedTable, parseTable} from '../utils/delimited'
 
 const props = defineProps<{
   output: string
@@ -70,102 +56,62 @@ const props = defineProps<{
 const emit = defineEmits<{ clear: [] }>()
 
 const viewMode = ref<'table' | 'chart'>('table')
-const displayLimit = 500
-
-const stable = ref(props.output)
-const applyOutput = debounce((v: string) => { stable.value = v }, 150)
-watch(() => props.output, (v) => applyOutput(v))
-
-// 根据首行推断分隔符（制表符优先支持 TSV，否则逗号）
-const detectDelimiter = (text: string): string => {
-  const firstLine = text.split('\n', 1)[0] || ''
-  const tabs = (firstLine.match(/\t/g) || []).length
-  const commas = (firstLine.match(/,/g) || []).length
-  const semis = (firstLine.match(/;/g) || []).length
-  if (tabs > 0 && tabs >= commas) {
-    return '\t'
-  }
-  if (semis > commas) {
-    return ';'
-  }
-  return ','
-}
+// shallowRef：大数组不做深度响应，避免开销
+const parsed = shallowRef<DelimitedTable>({columns: [], rows: []})
+const parsing = ref(false)
+const percent = ref(0)
 
-// 支持引号、转义引号("")、字段内换行的分隔解析
-const parseDelimited = (text: string, delim: string): string[][] => {
-  const rows: string[][] = []
-  let field = ''
-  let row: string[] = []
-  let inQuotes = false
-  for (let i = 0; i < text.length; i++) {
-    const c = text[i]
-    if (inQuotes) {
-      if (c === '"') {
-        if (text[i + 1] === '"') {
-          field += '"'
-          i++
-        }
-        else {
-          inQuotes = false
-        }
-      }
-      else {
-        field += c
-      }
-    }
-    else if (c === '"') {
-      inQuotes = true
+// 解析放到 Web Worker，超大文件不阻塞 UI；创建失败则主线程兜底
+let worker: Worker | null = null
+let reqId = 0
+type WorkerMsg = { id: number; type: 'progress'; percent: number } | { id: number; type: 'done' } & DelimitedTable
+try {
+  worker = new Worker(new URL('../workers/delimited.worker.ts', import.meta.url), {type: 'module'})
+  worker.onmessage = (e: MessageEvent<WorkerMsg>) => {
+    const msg = e.data
+    if (msg.id !== reqId) {
+      return // 丢弃过期结果
     }
-    else if (c === delim) {
-      row.push(field)
-      field = ''
+    if (msg.type === 'progress') {
+      percent.value = msg.percent
+      return
     }
-    else if (c === '\n') {
-      row.push(field)
-      rows.push(row)
-      row = []
-      field = ''
+    parsed.value = {columns: msg.columns, rows: msg.rows}
+    parsing.value = false
+    if (!parsed.value.columns.length && viewMode.value === 'chart') {
+      viewMode.value = 'table'
     }
-    else if (c !== '\r') {
-      field += c
-    }
-  }
-  if (field.length > 0 || row.length > 0) {
-    row.push(field)
-    rows.push(row)
   }
-  return rows
+}
+catch {
+  worker = null
 }
 
-const parsed = computed<{ columns: string[]; rows: string[][] }>(() => {
-  const text = stable.value.trim()
-  if (!text) {
-    return {columns: [], rows: []}
+const doParse = (text: string) => {
+  reqId++
+  percent.value = 0
+  if (!text.trim()) {
+    parsed.value = {columns: [], rows: []}
+    parsing.value = false
+    return
   }
-  const delim = detectDelimiter(text)
-  const all = parseDelimited(text, delim).filter(r => r.length > 1 || (r.length === 1 && r[0] !== ''))
-  if (all.length === 0) {
-    return {columns: [], rows: []}
+  if (worker) {
+    parsing.value = true
+    worker.postMessage({id: reqId, text})
   }
-  const columns = all[0].map((c, i) => c.trim() || `列${i + 1}`)
-  const rows = all.slice(1).map(r => {
-    const out = new Array(columns.length).fill('')
-    for (let i = 0; i < columns.length; i++) {
-      out[i] = r[i] ?? ''
+  else {
+    parsed.value = parseTable(text)
+    if (!parsed.value.columns.length && viewMode.value === 'chart') {
+      viewMode.value = 'table'
     }
-    return out
-  })
-  return {columns, rows}
-})
+  }
+}
 
-const displayRows = computed(() => parsed.value.rows.slice(0, displayLimit))
+const applyOutput = debounce((v: string) => doParse(v), 150)
+watch(() => props.output, (v) => applyOutput(v))
+doParse(props.output)
 
 const exportCsv = () => downloadCsv(parsed.value.columns, parsed.value.rows, `data-${Date.now()}.csv`)
 
-// 数据为空时回退表格视图
-watch(() => parsed.value.columns.length, (n) => {
-  if (!n && viewMode.value === 'chart') {
-    viewMode.value = 'table'
-  }
-})
+onBeforeUnmount(() => worker?.terminate())
 </script>
diff --git a/src/components/ResizablePanels.vue b/src/components/ResizablePanels.vue
index ab27d3d..fe8773d 100644
--- a/src/components/ResizablePanels.vue
+++ b/src/components/ResizablePanels.vue
@@ -1,7 +1,7 @@
 <template>
   <div ref="containerRef" class="overflow-hidden h-full w-full flex" :class="isVertical ? 'flex-col' : 'flex-row'">
     <!-- 主面板（编辑器） -->
-    <div :style="primaryStyle" class="overflow-hidden">
+    <div :style="primaryStyle" class="overflow-hidden min-h-0 min-w-0 flex-shrink-0">
       <slot name="primary"></slot>
     </div>
 
@@ -18,7 +18,7 @@
     </div>
 
     <!-- 副面板（控制台） -->
-    <div class="flex-1 overflow-hidden">
+    <div class="flex-1 min-h-0 min-w-0 overflow-hidden">
       <slot name="secondary"></slot>
     </div>
   </div>
diff --git a/src/components/SchemaBrowser.vue b/src/components/SchemaBrowser.vue
new file mode 100644
index 0000000..3ab0241
--- /dev/null
+++ b/src/components/SchemaBrowser.vue
@@ -0,0 +1,249 @@
+<template>
+  <div class="inline-block">
+    <button ref="btnRef" class="inline-flex items-center gap-1 px-2 py-0.5 rounded text-xs text-gray-500 dark:text-gray-400 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer"
+            title="数据库结构" @click="toggle">
+      <Database class="w-3.5 h-3.5"/>
+      <span>结构</span>
+    </button>
+
+    <Teleport to="body">
+      <template v-if="open">
+        <div class="fixed inset-0 z-[60]" @click="open = false"/>
+        <div class="fixed z-[61] w-72 overflow-auto rounded-md border border-gray-200 dark:border-gray-700 bg-white dark:bg-gray-800 shadow-lg text-xs"
+             :style="{left: pos.left + 'px', top: pos.top + 'px', maxHeight: pos.maxH + 'px'}">
+          <div class="sticky top-0 z-10 bg-white dark:bg-gray-800 border-b border-gray-200 dark:border-gray-700">
+            <div class="flex items-center justify-between px-3 py-2">
+              <span class="font-medium text-gray-600 dark:text-gray-300 truncate">结构 · {{ activeLabel() }}</span>
+              <button class="p-0.5 rounded text-gray-400 hover:text-gray-600 dark:hover:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer flex-shrink-0" title="刷新" @click="load">
+                <RefreshCw class="w-3.5 h-3.5" :class="loading ? 'animate-spin' : ''"/>
+              </button>
+            </div>
+            <div class="px-2 pb-2">
+              <input v-model="filter" type="text" :placeholder="mode === 'databases' ? '搜索数据库…' : '搜索表 / 字段…'"
+                     class="w-full px-2 py-1 text-xs rounded border border-gray-200 dark:border-gray-700 bg-gray-50 dark:bg-gray-900 text-gray-700 dark:text-gray-200 focus:outline-none focus:border-blue-400"/>
+            </div>
+          </div>
+
+          <div v-if="loading" class="px-3 py-4 text-center text-gray-400">加载中…</div>
+          <div v-else-if="error" class="px-3 py-3 text-red-500 whitespace-pre-wrap">{{ error }}</div>
+          <div v-else-if="mode === 'databases' && databases.length === 0" class="px-3 py-4 text-center text-gray-400">无数据库</div>
+          <div v-else-if="mode === 'tables' && tables.length === 0" class="px-3 py-4 text-center text-gray-400">无表</div>
+
+          <!-- 库 → 表 → 字段 -->
+          <div v-else-if="mode === 'databases'" class="py-1">
+            <div v-for="db in filteredDatabases" :key="db.name">
+              <div class="flex items-center gap-1 px-2 py-1 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer" @click="expandDb(db)">
+                <ChevronRight class="w-3 h-3 text-gray-400 transition-transform flex-shrink-0" :class="db.expanded ? 'rotate-90' : ''"/>
+                <Database class="w-3 h-3 text-amber-500 flex-shrink-0"/>
+                <span class="flex-1 truncate text-gray-700 dark:text-gray-200" :title="db.name">{{ db.name }}</span>
+                <RefreshCw v-if="db.loading" class="w-3 h-3 text-gray-400 animate-spin"/>
+              </div>
+              <div v-if="db.expanded && db.tables" class="pl-4">
+                <template v-for="t in matchTables(db.tables)" :key="t.name">
+                  <div class="group flex items-center gap-1 px-2 py-1 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer" @click="toggleTable(db.name + '.' + t.name)">
+                    <ChevronRight class="w-3 h-3 text-gray-400 transition-transform flex-shrink-0" :class="isOpen(db.name + '.' + t.name) ? 'rotate-90' : ''"/>
+                    <Table2 class="w-3 h-3 text-blue-500 flex-shrink-0"/>
+                    <span class="flex-1 truncate text-gray-700 dark:text-gray-200" :title="t.name" @click.stop="emit('insert', t.name)">{{ t.name }}</span>
+                    <span class="text-[10px] text-gray-400">{{ t.columns.length }}</span>
+                    <button class="opacity-0 group-hover:opacity-100 p-0.5 rounded text-gray-400 hover:text-blue-500 cursor-pointer" title="预览前 100 行" @click.stop="preview(t.name, db.name)">
+                      <Play class="w-3 h-3"/>
+                    </button>
+                  </div>
+                  <div v-if="isOpen(db.name + '.' + t.name)" class="pl-7 pr-2 pb-1">
+                    <div v-for="col in t.columns" :key="col.name" class="flex items-center justify-between gap-2 py-0.5 cursor-pointer hover:text-blue-500" :title="`插入列名：${col.name}`" @click="emit('insert', col.name)">
+                      <span class="truncate text-gray-600 dark:text-gray-300">{{ col.name }}</span>
+                      <span class="text-[10px] text-gray-400 flex-shrink-0">{{ col.type }}</span>
+                    </div>
+                  </div>
+                </template>
+                <div v-if="db.tables.length === 0" class="px-2 py-1 text-gray-400">无表</div>
+              </div>
+            </div>
+          </div>
+
+          <!-- 表 → 字段 -->
+          <div v-else class="py-1">
+            <template v-for="t in filteredTables" :key="t.name">
+              <div class="group flex items-center gap-1 px-2 py-1 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer" @click="toggleTable(t.name)">
+                <ChevronRight class="w-3 h-3 text-gray-400 transition-transform flex-shrink-0" :class="isOpen(t.name) ? 'rotate-90' : ''"/>
+                <Table2 class="w-3 h-3 text-blue-500 flex-shrink-0"/>
+                <span class="flex-1 truncate text-gray-700 dark:text-gray-200" :title="t.name" @click.stop="emit('insert', t.name)">{{ t.name }}</span>
+                <span class="text-[10px] text-gray-400">{{ t.columns.length }}</span>
+                <button class="opacity-0 group-hover:opacity-100 p-0.5 rounded text-gray-400 hover:text-blue-500 cursor-pointer" title="预览前 100 行" @click.stop="preview(t.name)">
+                  <Play class="w-3 h-3"/>
+                </button>
+              </div>
+              <div v-if="isOpen(t.name)" class="pl-7 pr-2 pb-1">
+                <div v-for="col in t.columns" :key="col.name" class="flex items-center justify-between gap-2 py-0.5 cursor-pointer hover:text-blue-500" :title="`插入列名：${col.name}`" @click="emit('insert', col.name)">
+                  <span class="truncate text-gray-600 dark:text-gray-300">{{ col.name }}</span>
+                  <span class="text-[10px] text-gray-400 flex-shrink-0">{{ col.type }}</span>
+                </div>
+              </div>
+            </template>
+          </div>
+        </div>
+      </template>
+    </Teleport>
+  </div>
+</template>
+
+<script setup lang="ts">
+import {computed, ref, watch} from 'vue'
+import {invoke} from '@tauri-apps/api/core'
+import {ChevronRight, Database, Play, RefreshCw, Table2} from 'lucide-vue-next'
+import {useDbConnections} from '../composables/useDbConnections'
+
+const emit = defineEmits<{ insert: [text: string]; preview: [sql: string] }>()
+
+const {resolveActiveSource, activeRef, activeLabel} = useDbConnections()
+
+interface Col { name: string; type: string }
+interface Tbl { name: string; columns: Col[] }
+interface Db { name: string; expanded: boolean; loading: boolean; tables: Tbl[] | null }
+
+const open = ref(false)
+const btnRef = ref<HTMLElement>()
+const pos = ref({left: 0, top: 0, maxH: 384})
+const loading = ref(false)
+const error = ref('')
+const mode = ref<'tables' | 'databases'>('tables')
+const tables = ref<Tbl[]>([])
+const databases = ref<Db[]>([])
+const expandedKeys = ref<Set<string>>(new Set())
+const filter = ref('')
+
+// 按名称/字段过滤
+const matchTables = (list: Tbl[]): Tbl[] => {
+  const q = filter.value.trim().toLowerCase()
+  if (!q) {
+    return list
+  }
+  return list.filter(t => t.name.toLowerCase().includes(q) || t.columns.some(c => c.name.toLowerCase().includes(q)))
+}
+const filteredTables = computed(() => matchTables(tables.value))
+const filteredDatabases = computed(() => {
+  const q = filter.value.trim().toLowerCase()
+  if (!q) {
+    return databases.value
+  }
+  return databases.value.filter(d => d.name.toLowerCase().includes(q))
+})
+
+const quote = (kind: string, name: string) => (kind === 'mysql' ? `\`${name}\`` : `"${name}"`)
+const esc = (s: string) => s.replace(/'/g, "''")
+
+const tablesSql = (kind: string, db?: string): string => {
+  if (kind === 'mysql') {
+    return 'SELECT table_name AS tbl, column_name AS col, column_type AS typ '
+      + `FROM information_schema.columns WHERE table_schema = '${esc(db || '')}' `
+      + 'ORDER BY table_name, ordinal_position'
+  }
+  return 'SELECT m.name AS tbl, p.name AS col, p.type AS typ '
+    + 'FROM sqlite_master m JOIN pragma_table_info(m.name) p '
+    + "WHERE m.type IN ('table','view') AND m.name NOT LIKE 'sqlite\\_%' ESCAPE '\\' "
+    + 'ORDER BY m.name, p.cid'
+}
+
+const runRows = async (sql: string): Promise<any[][]> => {
+  const source = resolveActiveSource()
+  const res = await invoke<any>('run_sql', {sql, source})
+  if (res.error) {
+    throw new Error(res.error)
+  }
+  return (res.result_sets || [])[0]?.rows || []
+}
+
+const groupTables = (rows: any[][]): Tbl[] => {
+  const map = new Map<string, Tbl>()
+  for (const row of rows) {
+    const tbl = String(row[0])
+    if (!map.has(tbl)) {
+      map.set(tbl, {name: tbl, columns: []})
+    }
+    map.get(tbl)!.columns.push({name: String(row[1]), type: String(row[2] ?? '')})
+  }
+  return [...map.values()]
+}
+
+const load = async () => {
+  loading.value = true
+  error.value = ''
+  expandedKeys.value = new Set()
+  filter.value = ''
+  try {
+    const source = resolveActiveSource()
+    if (source.kind === 'mysql' && !source.database) {
+      // 未指定库：列出数据库，按需展开
+      mode.value = 'databases'
+      const rows = await runRows(
+        'SELECT schema_name FROM information_schema.schemata '
+        + "WHERE schema_name NOT IN ('information_schema','mysql','performance_schema','sys') "
+        + 'ORDER BY schema_name'
+      )
+      databases.value = rows.map(r => ({name: String(r[0]), expanded: false, loading: false, tables: null}))
+    }
+    else {
+      mode.value = 'tables'
+      const db = source.kind === 'mysql' ? source.database || undefined : undefined
+      tables.value = groupTables(await runRows(tablesSql(source.kind, db)))
+    }
+  }
+  catch (e: any) {
+    error.value = e?.message || String(e)
+    tables.value = []
+    databases.value = []
+  }
+  finally {
+    loading.value = false
+  }
+}
+
+const expandDb = async (db: Db) => {
+  if (!db.expanded && db.tables == null) {
+    db.loading = true
+    try {
+      db.tables = groupTables(await runRows(tablesSql('mysql', db.name)))
+    }
+    catch {
+      db.tables = []
+    }
+    finally {
+      db.loading = false
+    }
+  }
+  db.expanded = !db.expanded
+}
+
+const isOpen = (key: string) => expandedKeys.value.has(key)
+const toggleTable = (key: string) => {
+  const s = new Set(expandedKeys.value)
+  s.has(key) ? s.delete(key) : s.add(key)
+  expandedKeys.value = s
+}
+
+const preview = (name: string, db?: string) => {
+  const kind = resolveActiveSource().kind
+  const qualified = db ? `${quote(kind, db)}.${quote(kind, name)}` : quote(kind, name)
+  emit('preview', `SELECT * FROM ${qualified} LIMIT 100`)
+  open.value = false
+}
+
+const toggle = () => {
+  open.value = !open.value
+  if (open.value) {
+    const r = btnRef.value?.getBoundingClientRect()
+    if (r) {
+      const top = r.bottom + 4
+      const left = Math.min(r.left, window.innerWidth - 288 - 8)
+      pos.value = {left: Math.max(8, left), top, maxH: Math.max(200, Math.min(380, window.innerHeight - top - 12))}
+    }
+    load()
+  }
+}
+
+watch(activeRef, () => {
+  if (open.value) {
+    load()
+  }
+})
+</script>
diff --git a/src/components/SqlResultTable.vue b/src/components/SqlResultTable.vue
index ff4053e..8d1cd57 100644
--- a/src/components/SqlResultTable.vue
+++ b/src/components/SqlResultTable.vue
@@ -11,26 +11,11 @@
       <!-- 非查询语句的消息 -->
       <div v-for="(m, mi) in result.messages" :key="'m' + mi" class="mb-1 text-green-600 dark:text-green-400">✓ {{ m }}</div>
 
-      <!-- 结果集表格 -->
+      <!-- 结果集表格（虚拟滚动，限高以适配多结果集堆叠） -->
       <div v-for="(rs, ri) in result.result_sets" :key="ri" class="mb-4">
         <div v-if="result.result_sets.length > 1" class="text-[11px] text-gray-400 mb-1">结果集 {{ ri + 1 }} · {{ rs.rows.length }} 行</div>
-        <div class="overflow-x-auto border border-gray-200 dark:border-gray-700 rounded">
-          <table class="w-full border-collapse">
-            <thead>
-              <tr class="bg-gray-50 dark:bg-gray-800">
-                <th v-for="(c, ci) in rs.columns" :key="ci" class="text-left font-semibold px-3 py-1.5 border-b border-gray-200 dark:border-gray-700 text-gray-600 dark:text-gray-300 whitespace-nowrap">{{ c }}</th>
-              </tr>
-            </thead>
-            <tbody>
-              <tr v-for="(row, i) in rs.rows" :key="i" class="hover:bg-gray-50 dark:hover:bg-gray-800/50">
-                <td v-for="(_c, ci) in rs.columns" :key="ci" class="px-3 py-1 border-b border-gray-100 dark:border-gray-800 font-mono whitespace-nowrap"
-                    :class="row[ci] === null ? 'text-gray-400 italic' : 'text-gray-700 dark:text-gray-300'">{{ fmt(row[ci]) }}</td>
-              </tr>
-              <tr v-if="rs.rows.length === 0">
-                <td :colspan="rs.columns.length" class="px-3 py-2 text-center text-gray-400">（0 行）</td>
-              </tr>
-            </tbody>
-          </table>
+        <div class="border border-gray-200 dark:border-gray-700 rounded overflow-hidden">
+          <VirtualTable :columns="rs.columns" :rows="rs.rows" :show-index="false" :max-height="420"/>
         </div>
       </div>
 
@@ -44,6 +29,7 @@
 
 <script setup lang="ts">
 import {computed} from 'vue'
+import VirtualTable from './VirtualTable.vue'
 
 interface ResultSet { columns: string[]; rows: any[][] }
 interface SqlResult { result_sets: ResultSet[]; messages: string[]; error: string | null; elapsed_ms: number }
@@ -61,10 +47,4 @@ const result = computed<SqlResult | null>(() => {
     return null
   }
 })
-
-const fmt = (v: any) => {
-  if (v === null || v === undefined) return 'NULL'
-  if (typeof v === 'object') return JSON.stringify(v)
-  return String(v)
-}
 </script>
diff --git a/src/components/SqlTableView.vue b/src/components/SqlTableView.vue
index 4154e3b..8a32f9b 100644
--- a/src/components/SqlTableView.vue
+++ b/src/components/SqlTableView.vue
@@ -30,7 +30,7 @@
     </div>
 
     <!-- 图表视图 -->
-    <div v-if="viewMode === 'chart' && firstResultSet" class="flex-1 min-h-0">
+    <div v-if="viewMode === 'chart' && firstResultSet" class="flex-1 min-h-0 overflow-hidden">
       <ChartPanel :columns="firstResultSet.columns" :rows="firstResultSet.rows"/>
     </div>
     <!-- 表格视图 -->
diff --git a/src/components/VirtualTable.vue b/src/components/VirtualTable.vue
new file mode 100644
index 0000000..b742080
--- /dev/null
+++ b/src/components/VirtualTable.vue
@@ -0,0 +1,172 @@
+<template>
+  <div ref="scroller" class="overflow-auto" :class="maxHeight ? '' : 'h-full'" :style="maxHeight ? {maxHeight: maxHeight + 'px'} : undefined" @scroll="onScroll">
+    <table class="w-full border-collapse text-xs" style="table-layout: auto">
+      <thead class="sticky top-0 z-10">
+        <tr class="bg-gray-50 dark:bg-gray-800">
+          <th v-if="showIndex" class="text-left font-semibold px-2 py-1.5 border-b border-gray-200 dark:border-gray-700 text-gray-400 w-12">#</th>
+          <th v-for="(c, ci) in columns" :key="ci" :style="colStyle(ci)"
+              class="relative text-left font-semibold px-3 py-1.5 border-b border-gray-200 dark:border-gray-700 text-gray-600 dark:text-gray-300 overflow-hidden whitespace-nowrap text-ellipsis cursor-pointer select-none hover:bg-gray-100 dark:hover:bg-gray-700/50"
+              :title="c" @click="toggleSort(ci)">
+            {{ c }}<span v-if="sortCol === ci" class="text-blue-500">{{ sortDir === 1 ? ' ▲' : ' ▼' }}</span>
+            <span class="absolute top-0 right-0 h-full w-1.5 cursor-col-resize hover:bg-blue-400/60" @click.stop @mousedown.stop.prevent="startResize(ci, $event)"/>
+          </th>
+        </tr>
+      </thead>
+      <tbody>
+        <tr v-if="topPad > 0" :style="{height: topPad + 'px'}"><td :colspan="colCount"/></tr>
+        <tr v-for="(row, i) in visibleRows" :key="start + i" class="hover:bg-gray-50 dark:hover:bg-gray-800/50" :style="{height: rowHeight + 'px'}">
+          <td v-if="showIndex" class="px-2 border-b border-gray-100 dark:border-gray-800 text-gray-400 whitespace-nowrap">{{ start + i + 1 }}</td>
+          <td v-for="(_c, ci) in columns" :key="ci" :style="colStyle(ci)" class="px-3 border-b border-gray-100 dark:border-gray-800 font-mono overflow-hidden whitespace-nowrap text-ellipsis"
+              :class="row[ci] === null || row[ci] === undefined ? 'text-gray-400 italic' : 'text-gray-700 dark:text-gray-300'" :title="fmt(row[ci])">{{ fmt(row[ci]) }}</td>
+        </tr>
+        <tr v-if="bottomPad > 0" :style="{height: bottomPad + 'px'}"><td :colspan="colCount"/></tr>
+        <tr v-if="rows.length === 0">
+          <td :colspan="colCount" class="px-3 py-2 text-center text-gray-400">（0 行）</td>
+        </tr>
+      </tbody>
+    </table>
+  </div>
+</template>
+
+<script setup lang="ts">
+import {computed, onBeforeUnmount, onMounted, ref, watch} from 'vue'
+
+const props = withDefaults(defineProps<{
+  columns: string[]
+  rows: any[][]
+  rowHeight?: number
+  showIndex?: boolean
+  buffer?: number
+  maxHeight?: number
+}>(), {rowHeight: 28, showIndex: true, buffer: 8})
+
+const scroller = ref<HTMLElement>()
+const scrollTop = ref(0)
+const viewportH = ref(0)
+
+const onScroll = () => {
+  scrollTop.value = scroller.value?.scrollTop || 0
+}
+
+const colCount = computed(() => props.columns.length + (props.showIndex ? 1 : 0))
+
+// ---- 列宽：默认自动（按内容），仅被拖拽过的列施加显式宽度 ----
+const widths = ref<(number | undefined)[]>([])
+watch(() => props.columns, () => {
+  widths.value = props.columns.map(() => undefined)
+}, {immediate: true})
+const colStyle = (ci: number) => {
+  const w = widths.value[ci]
+  return w != null ? {width: w + 'px', maxWidth: w + 'px'} : undefined
+}
+
+let resizing = -1
+let startX = 0
+let startW = 0
+const onResizeMove = (e: MouseEvent) => {
+  if (resizing < 0) {
+    return
+  }
+  const w = Math.max(48, startW + (e.clientX - startX))
+  const arr = [...widths.value]
+  arr[resizing] = w
+  widths.value = arr
+}
+const onResizeUp = () => {
+  resizing = -1
+  document.removeEventListener('mousemove', onResizeMove)
+  document.removeEventListener('mouseup', onResizeUp)
+}
+const startResize = (ci: number, e: MouseEvent) => {
+  resizing = ci
+  startX = e.clientX
+  // 从当前渲染宽度起拖（自动列也能接管）
+  const th = (e.target as HTMLElement).parentElement as HTMLElement | null
+  startW = widths.value[ci] ?? (th ? th.getBoundingClientRect().width : 120)
+  document.addEventListener('mousemove', onResizeMove)
+  document.addEventListener('mouseup', onResizeUp)
+}
+
+// ---- 排序（点击列头：升 → 降 → 取消） ----
+const sortCol = ref(-1)
+const sortDir = ref<1 | -1>(1)
+const toggleSort = (ci: number) => {
+  if (sortCol.value !== ci) {
+    sortCol.value = ci
+    sortDir.value = 1
+  }
+  else if (sortDir.value === 1) {
+    sortDir.value = -1
+  }
+  else {
+    sortCol.value = -1
+  }
+}
+const compare = (a: any, b: any): number => {
+  const an = a === null || a === undefined || a === ''
+  const bn = b === null || b === undefined || b === ''
+  if (an && bn) {
+    return 0
+  }
+  if (an) {
+    return 1
+  }
+  if (bn) {
+    return -1
+  }
+  const na = Number(a)
+  const nb = Number(b)
+  if (!isNaN(na) && !isNaN(nb)) {
+    return na - nb
+  }
+  return String(a).localeCompare(String(b))
+}
+const sortedRows = computed(() => {
+  if (sortCol.value < 0) {
+    return props.rows
+  }
+  const ci = sortCol.value
+  const dir = sortDir.value
+  return [...props.rows].sort((a, b) => compare(a[ci], b[ci]) * dir)
+})
+watch(() => props.columns, () => {
+  sortCol.value = -1
+})
+
+// ---- 虚拟滚动窗口 ----
+const start = computed(() => Math.max(0, Math.floor(scrollTop.value / props.rowHeight) - props.buffer))
+const end = computed(() => {
+  const visible = Math.ceil((viewportH.value || 1) / props.rowHeight) + props.buffer * 2
+  return Math.min(sortedRows.value.length, start.value + visible)
+})
+const visibleRows = computed(() => sortedRows.value.slice(start.value, end.value))
+const topPad = computed(() => start.value * props.rowHeight)
+const bottomPad = computed(() => (sortedRows.value.length - end.value) * props.rowHeight)
+
+const fmt = (v: any) => {
+  if (v === null || v === undefined) {
+    return 'NULL'
+  }
+  if (typeof v === 'object') {
+    return JSON.stringify(v)
+  }
+  return String(v)
+}
+
+let ro: ResizeObserver | null = null
+onMounted(() => {
+  if (!scroller.value) {
+    return
+  }
+  viewportH.value = scroller.value.clientHeight
+  ro = new ResizeObserver(() => {
+    viewportH.value = scroller.value?.clientHeight || 0
+  })
+  ro.observe(scroller.value)
+})
+onBeforeUnmount(() => {
+  ro?.disconnect()
+  document.removeEventListener('mousemove', onResizeMove)
+  document.removeEventListener('mouseup', onResizeUp)
+})
+</script>
diff --git a/src/components/charts/ChartPanel.vue b/src/components/charts/ChartPanel.vue
index 4808ab8..85c44e0 100644
--- a/src/components/charts/ChartPanel.vue
+++ b/src/components/charts/ChartPanel.vue
@@ -1,7 +1,7 @@
 <template>
-  <div class="flex h-full min-h-0">
+  <div class="flex h-full min-h-0 overflow-hidden">
     <!-- 配置侧栏 -->
-    <div class="w-56 flex-shrink-0 border-r border-gray-200 dark:border-gray-700 flex flex-col min-h-0 bg-gray-50 dark:bg-gray-800/40 overflow-auto">
+    <div class="w-56 flex-shrink-0 border-r border-gray-200 dark:border-gray-700 flex flex-col min-h-0 h-full bg-gray-50 dark:bg-gray-800/40 overflow-y-auto">
       <!-- 图表类型 -->
       <div class="px-3 py-2 border-b border-gray-200 dark:border-gray-700">
         <div class="text-[11px] text-gray-400 mb-1">图表类型</div>
@@ -10,12 +10,14 @@
 
       <!-- 可用字段 -->
       <div class="px-3 py-2 border-b border-gray-200 dark:border-gray-700">
-        <div class="text-[11px] text-gray-400 mb-1.5">字段（拖拽 / 双击）</div>
+        <div class="text-[11px] text-gray-400 mb-1.5">字段（单击选择 / 双击快速添加 / 可拖拽）</div>
         <div class="flex flex-wrap gap-1.5">
           <div v-for="f in fields" :key="f.name" draggable="true"
-               class="inline-flex items-center gap-1 px-2 py-1 rounded border text-xs cursor-grab active:cursor-grabbing select-none bg-white dark:bg-gray-800 border-gray-200 dark:border-gray-700 hover:border-blue-400"
+               class="inline-flex items-center gap-1 px-2 py-1 rounded border text-xs cursor-pointer active:cursor-grabbing select-none bg-white dark:bg-gray-800 border-gray-200 dark:border-gray-700 hover:border-blue-400"
+               title="单击选择位置 / 双击快速添加 / 拖拽到下方"
                @dragstart="onDragStart($event, f.name)"
-               @dblclick="quickAdd(f)">
+               @click="openFieldMenu(f, $event)"
+               @dblclick="dblAdd(f)">
             <component :is="f.numeric ? Hash : Type" class="w-3 h-3" :class="f.numeric ? 'text-emerald-500' : 'text-amber-500'"/>
             {{ f.name }}
           </div>
@@ -99,7 +101,7 @@
     </div>
 
     <!-- 图表区 -->
-    <div ref="chartHost" class="relative flex-1 min-w-0 min-h-0 p-3">
+    <div ref="chartHost" class="relative flex-1 min-w-0 min-h-0 overflow-hidden p-3">
       <div v-if="ready" class="absolute top-2 right-2 z-20">
         <button class="p-1.5 rounded-md text-gray-400 hover:text-gray-600 dark:hover:text-gray-300 bg-white/70 dark:bg-gray-800/70 hover:bg-gray-100 dark:hover:bg-gray-700 backdrop-blur cursor-pointer"
                 title="导出 / 复制" @click="menuOpen = !menuOpen">
@@ -147,6 +149,26 @@
       <MapChart v-else-if="chartType === 'mapChina'" map-type="china" :data="pieData" :max="mapMax"/>
       <MapChart v-else-if="chartType === 'mapWorld'" map-type="world" :data="pieData" :max="mapMax"/>
     </div>
+
+    <!-- 单击字段：选择添加到维度/指标（或散点的 X/Y/分组） -->
+    <Teleport to="body">
+      <template v-if="fieldMenu">
+        <div class="fixed inset-0 z-[60]" @click="fieldMenu = null"/>
+        <div class="fixed z-[61] min-w-28 py-1 rounded-md border border-gray-200 dark:border-gray-700 bg-white dark:bg-gray-800 shadow-lg text-xs"
+             :style="{left: fieldMenu.left + 'px', top: fieldMenu.top + 'px'}">
+          <div class="px-3 py-1 text-[11px] text-gray-400 border-b border-gray-200 dark:border-gray-700 truncate">{{ fieldMenu.name }}</div>
+          <template v-if="meta.layout === 'scatter'">
+            <button class="w-full text-left px-3 py-1.5 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer text-gray-600 dark:text-gray-300" @click="pickTarget('x')">设为 X 指标</button>
+            <button class="w-full text-left px-3 py-1.5 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer text-gray-600 dark:text-gray-300" @click="pickTarget('y')">设为 Y 指标</button>
+            <button class="w-full text-left px-3 py-1.5 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer text-gray-600 dark:text-gray-300" @click="pickTarget('group')">设为分组</button>
+          </template>
+          <template v-else>
+            <button class="w-full text-left px-3 py-1.5 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer text-blue-600 dark:text-blue-300" @click="pickTarget('dim')">加为维度</button>
+            <button class="w-full text-left px-3 py-1.5 hover:bg-gray-100 dark:hover:bg-gray-700 cursor-pointer text-emerald-600 dark:text-emerald-300" @click="pickTarget('metric')">加为指标</button>
+          </template>
+        </div>
+      </template>
+    </Teleport>
   </div>
 </template>
 
@@ -464,7 +486,7 @@ const onDropScatter = (zone: 'x' | 'y' | 'group') => {
   dragField = ''
 }
 
-// 双击快速添加
+// 双击快速添加：数值列→指标，文本列→维度（散点：依次 X/Y/分组）
 const quickAdd = (f: { name: string; numeric: boolean }) => {
   if (meta.value.layout === 'scatter') {
     if (f.numeric) {
@@ -490,6 +512,54 @@ const quickAdd = (f: { name: string; numeric: boolean }) => {
   }
 }
 
+// 单击字段：在其右侧弹出菜单（延迟以便与双击区分）；双击则快速添加
+const fieldMenu = ref<{ name: string; left: number; top: number } | null>(null)
+let clickTimer: ReturnType<typeof setTimeout> | null = null
+const openFieldMenu = (f: { name: string }, e: MouseEvent) => {
+  const r = (e.currentTarget as HTMLElement).getBoundingClientRect()
+  const left = Math.min(r.right + 6, window.innerWidth - 140)
+  if (clickTimer) {
+    clearTimeout(clickTimer)
+  }
+  clickTimer = setTimeout(() => {
+    fieldMenu.value = {name: f.name, left, top: r.top}
+    clickTimer = null
+  }, 220)
+}
+const dblAdd = (f: { name: string; numeric: boolean }) => {
+  if (clickTimer) {
+    clearTimeout(clickTimer)
+    clickTimer = null
+  }
+  quickAdd(f)
+}
+const pickTarget = (target: 'dim' | 'metric' | 'x' | 'y' | 'group') => {
+  const name = fieldMenu.value?.name
+  if (!name) {
+    return
+  }
+  if (target === 'dim') {
+    if (!dimensions.value.includes(name)) {
+      dimensions.value = [...dimensions.value, name]
+    }
+  }
+  else if (target === 'metric') {
+    if (!metrics.value.includes(name)) {
+      metrics.value = [...metrics.value, name]
+    }
+  }
+  else if (target === 'x') {
+    xField.value = name
+  }
+  else if (target === 'y') {
+    yField.value = name
+  }
+  else if (target === 'group') {
+    groupField.value = name
+  }
+  fieldMenu.value = null
+}
+
 const removeDim = (d: string) => {
   dimensions.value = dimensions.value.filter(x => x !== d)
 }
diff --git a/src/utils/delimited.ts b/src/utils/delimited.ts
new file mode 100644
index 0000000..9cfac67
--- /dev/null
+++ b/src/utils/delimited.ts
@@ -0,0 +1,94 @@
+// CSV / TSV 等分隔文本解析（纯函数，供主线程与 Web Worker 复用）
+
+export interface DelimitedTable {
+  columns: string[]
+  rows: string[][]
+}
+
+/** 根据首行推断分隔符（制表符优先支持 TSV，其次分号，默认逗号） */
+export function detectDelimiter(text: string): string {
+  const firstLine = text.split('\n', 1)[0] || ''
+  const tabs = (firstLine.match(/\t/g) || []).length
+  const commas = (firstLine.match(/,/g) || []).length
+  const semis = (firstLine.match(/;/g) || []).length
+  if (tabs > 0 && tabs >= commas) {
+    return '\t'
+  }
+  if (semis > commas) {
+    return ';'
+  }
+  return ','
+}
+
+/** 支持引号、转义引号("")、字段内换行的分隔解析，返回二维数组；onProgress 报告 0~1 进度 */
+export function parseDelimited(text: string, delim: string, onProgress?: (p: number) => void): string[][] {
+  const rows: string[][] = []
+  let field = ''
+  let row: string[] = []
+  let inQuotes = false
+  const len = text.length
+  const step = onProgress ? Math.max(1, Math.floor(len / 100)) : 0
+  for (let i = 0; i < len; i++) {
+    if (step && i % step === 0) {
+      onProgress!(i / len)
+    }
+    const c = text[i]
+    if (inQuotes) {
+      if (c === '"') {
+        if (text[i + 1] === '"') {
+          field += '"'
+          i++
+        }
+        else {
+          inQuotes = false
+        }
+      }
+      else {
+        field += c
+      }
+    }
+    else if (c === '"') {
+      inQuotes = true
+    }
+    else if (c === delim) {
+      row.push(field)
+      field = ''
+    }
+    else if (c === '\n') {
+      row.push(field)
+      rows.push(row)
+      row = []
+      field = ''
+    }
+    else if (c !== '\r') {
+      field += c
+    }
+  }
+  if (field.length > 0 || row.length > 0) {
+    row.push(field)
+    rows.push(row)
+  }
+  return rows
+}
+
+/** 解析为表格：首行作列名，其余对齐为等长行；onProgress 报告 0~1 进度 */
+export function parseTable(text: string, onProgress?: (p: number) => void): DelimitedTable {
+  const trimmed = text.trim()
+  if (!trimmed) {
+    return {columns: [], rows: []}
+  }
+  const delim = detectDelimiter(trimmed)
+  const all = parseDelimited(trimmed, delim, onProgress).filter(r => r.length > 1 || (r.length === 1 && r[0] !== ''))
+  if (all.length === 0) {
+    return {columns: [], rows: []}
+  }
+  const columns = all[0].map((c, i) => c.trim() || `列${i + 1}`)
+  const rows = all.slice(1).map(r => {
+    const out: string[] = new Array(columns.length).fill('')
+    for (let i = 0; i < columns.length; i++) {
+      out[i] = r[i] ?? ''
+    }
+    return out
+  })
+  return {columns, rows}
+}
diff --git a/src/workers/delimited.worker.ts b/src/workers/delimited.worker.ts
new file mode 100644
index 0000000..5a3409b
--- /dev/null
+++ b/src/workers/delimited.worker.ts
@@ -0,0 +1,27 @@
+// CSV / TSV 解析 Worker：后台解析并上报进度，避免超大文件阻塞 UI
+import {parseTable} from '../utils/delimited'
+
+interface ParseRequest {
+  id: number
+  text: string
+}
+
+const post = (msg: any) => (self as unknown as Worker).postMessage(msg)
+
+self.onmessage = (e: MessageEvent<ParseRequest>) => {
+  const {id, text} = e.data
+  try {
+    let lastPercent = -1
+    const table = parseTable(text, (p) => {
+      const percent = Math.floor(p * 100)
+      if (percent !== lastPercent) {
+        lastPercent = percent
+        post({id, type: 'progress', percent})
+      }
+    })
+    post({id, type: 'done', columns: table.columns, rows: table.rows})
+  }
+  catch {
+    post({id, type: 'done', columns: [], rows: []})
+  }
+}