diff --git a/config/config.js b/config/config.js
index 6d3e466..e93bec1 100644
--- a/config/config.js
+++ b/config/config.js
@@ -250,7 +250,7 @@ class ChatGPTConfig {
       historyPollInterval: 300,
       historyBatchSize: 120,
       promptHeader: '# 以下是一些该群聊中可能相关的事实，你可以参考，但不要主动透露这些事实。',
-      promptItemTemplate: '- ${fact}${topicSuffix}',
+      promptItemTemplate: '- ${fact}${topicSuffix}${timeSuffix}',
       promptFooter: '',
       extractionSystemPrompt: `You are a knowledge extraction assistant that specialises in summarising long-term facts from group chat transcripts.
 Read the provided conversation and identify statements that should be stored as long-term knowledge for the group.
@@ -282,7 +282,7 @@ Only include meaningful, verifiable group-specific information that is useful fo
       maxRelevantItemsPerQuery: 3,
       minImportanceForInjection: 0,
       promptHeader: '# 用户画像',
-      promptItemTemplate: '- ${value}',
+      promptItemTemplate: '- ${value}${timeSuffix}',
       promptFooter: '',
       extractionSystemPrompt: `You are an assistant that extracts long-term personal preferences or persona details about a user.
 Given a conversation snippet between the user and the bot, identify durable information such as preferences, nicknames, roles, speaking style, habits, or other facts that remain valid over time.
@@ -453,20 +453,13 @@ Return a JSON array of **strings**, and nothing else, without any other characte
         ? JSON.parse(content)
         : yaml.load(content)
 
-      // 只更新存在的配置项
+      // 处理加载的配置并和默认值合并
       if (loadedConfig) {
-        Object.keys(loadedConfig).forEach(key => {
-          if (['version', 'basic', 'bym', 'llm', 'management', 'chaite', 'memory'].includes(key)) {
-            if (typeof loadedConfig[key] === 'object' && loadedConfig[key] !== null) {
-              // 对象的合并
-              if (!this[key]) this[key] = {}
-              Object.assign(this[key], loadedConfig[key])
-            } else {
-              // 基本类型直接赋值
-              this[key] = loadedConfig[key]
-            }
-          }
-        })
+        const mergeResult = this._mergeConfig(loadedConfig)
+        if (mergeResult.changed) {
+          logger?.debug?.('[Config] merged new defaults into persisted config; scheduling save')
+          this._triggerSave('code')
+        }
       }
 
       logger.debug('Config loaded successfully')
@@ -475,6 +468,68 @@ Return a JSON array of **strings**, and nothing else, without any other characte
     }
   }
 
+  _mergeConfig (loadedConfig) {
+    let changed = false
+
+    const mergeInto = (target, source) => {
+      if (!source || typeof source !== 'object') {
+        return target
+      }
+      if (!target || typeof target !== 'object') {
+        target = Array.isArray(source) ? [] : {}
+      }
+      const result = Array.isArray(source) ? [] : { ...target }
+
+      if (Array.isArray(source)) {
+        return source.slice()
+      }
+
+      const targetKeys = target && typeof target === 'object'
+        ? Object.keys(target)
+        : []
+      for (const key of targetKeys) {
+        if (!Object.prototype.hasOwnProperty.call(source, key)) {
+          changed = true
+        }
+      }
+
+      for (const key of Object.keys(source)) {
+        const sourceValue = source[key]
+        const targetValue = target[key]
+        if (sourceValue && typeof sourceValue === 'object' && !Array.isArray(sourceValue)) {
+          result[key] = mergeInto(targetValue, sourceValue)
+        } else {
+          if (targetValue === undefined || targetValue !== sourceValue) {
+            changed = true
+          }
+          result[key] = sourceValue
+        }
+      }
+      return result
+    }
+
+    const sections = ['version', 'basic', 'bym', 'llm', 'management', 'chaite', 'memory']
+    for (const key of sections) {
+      const loadedValue = loadedConfig[key]
+      if (loadedValue === undefined) {
+        continue
+      }
+      if (typeof loadedValue === 'object' && loadedValue !== null) {
+        const merged = mergeInto(this[key], loadedValue)
+        if (merged !== this[key]) {
+          this[key] = merged
+        }
+      } else {
+        if (this[key] !== loadedValue) {
+          changed = true
+        }
+        this[key] = loadedValue
+      }
+    }
+
+    return { changed }
+  }
+
   // 合并触发保存，防抖处理
   _triggerSave (origin) {
     // 清除之前的定时器
@@ -482,20 +537,18 @@ Return a JSON array of **strings**, and nothing else, without any other characte
       clearTimeout(this._saveTimer)
     }
 
-    // 记录保存来源
-    this._saveOrigin = origin || 'code'
-
-    // 设置定时器延迟保存
+    const originLabel = origin || 'code'
+    this._saveOrigin = originLabel
     this._saveTimer = setTimeout(() => {
-      this.saveToFile()
-      // 保存完成后延迟一下再清除来源标记
-      setTimeout(() => {
-        this._saveOrigin = null
-      }, 100)
+      this.saveToFile(originLabel)
+      this._saveOrigin = null
     }, 200)
   }
 
-  saveToFile () {
+  saveToFile (origin = 'code') {
+    if (origin !== 'code') {
+      this._saveOrigin = 'external'
+    }
     logger.debug('Saving config to file...')
     try {
       const config = {
diff --git a/models/memory/database.js b/models/memory/database.js
index c19acfd..63fbe3d 100644
--- a/models/memory/database.js
+++ b/models/memory/database.js
@@ -610,15 +610,7 @@ function ensureVectorTable (db) {
   let tablePresent = tableExists
 
   let needsTableReset = false
-  if (storedModel && storedModel !== currentModel) {
-    needsTableReset = true
-  } else if (!storedModel && tableExists) {
-    // Unknown model metadata but table exists; keep it as-is.
-    dimension = storedDimension
-  }
-
   if (tableExists && storedDimension <= 0) {
-    logger?.warn?.('[Memory] vec_group_facts exists but stored dimension is invalid, rebuilding table')
     needsTableReset = true
   }
 
@@ -628,11 +620,11 @@ function ensureVectorTable (db) {
       tablePresent = false
       dimension = 0
     } catch (err) {
-      logger?.warn?.('[Memory] failed to drop vec_group_facts during model change:', err)
+      logger?.warn?.('[Memory] failed to drop vec_group_facts during dimension change:', err)
     }
   }
 
-  if (!tablePresent) {
+if (!tablePresent) {
     if (dimension <= 0) {
       dimension = parseDimension(preferredDimension)
     }
@@ -640,30 +632,36 @@ function ensureVectorTable (db) {
       try {
         createVectorTable(db, dimension)
         tablePresent = true
+        setMetaValue(db, META_VECTOR_MODEL_KEY, currentModel)
+        setMetaValue(db, META_VECTOR_DIM_KEY, String(dimension))
+        cachedVectorDimension = dimension
+        cachedVectorModel = currentModel
+        return cachedVectorDimension
       } catch (err) {
         logger?.error?.('[Memory] failed to (re)create vec_group_facts table:', err)
         dimension = 0
       }
     }
-  } else if (dimension > 0 && preferredDimension > 0 && dimension !== preferredDimension) {
-    logger?.debug?.('[Memory] vector table dimension (%s) differs from preferred (%s); keeping existing table', dimension, preferredDimension)
   }
 
-  const metaDimensionValue = dimension > 0 ? String(dimension) : '0'
-  setMetaValue(db, META_VECTOR_MODEL_KEY, currentModel)
-  setMetaValue(db, META_VECTOR_DIM_KEY, metaDimensionValue)
+  if (tablePresent && storedDimension > 0) {
+    cachedVectorDimension = storedDimension
+    cachedVectorModel = storedModel || currentModel
+    return cachedVectorDimension
+  }
 
-  cachedVectorDimension = dimension > 0 ? dimension : 0
+  // At this point we failed to determine a valid dimension, set metadata to 0 to avoid loops.
+  setMetaValue(db, META_VECTOR_MODEL_KEY, currentModel)
+  setMetaValue(db, META_VECTOR_DIM_KEY, '0')
+  cachedVectorDimension = 0
   cachedVectorModel = currentModel
   return cachedVectorDimension
 }
-
 export function resetVectorTableDimension (dimension) {
   if (!Number.isFinite(dimension) || dimension <= 0) {
     throw new Error(`Invalid vector dimension: ${dimension}`)
   }
   const db = getMemoryDatabase()
-  logger?.info?.('[Memory] resetting group vector table dimension to %s', dimension)
   try {
     db.exec('DROP TABLE IF EXISTS vec_group_facts')
   } catch (err) {
@@ -726,7 +724,12 @@ export function getMemoryDatabase () {
 }
 
 export function getVectorDimension () {
-  if (cachedVectorDimension) {
+  const currentModel = ChatGPTConfig.llm?.embeddingModel || ''
+  if (cachedVectorModel && cachedVectorModel !== currentModel) {
+    cachedVectorDimension = null
+    cachedVectorModel = null
+  }
+  if (cachedVectorDimension !== null) {
     return cachedVectorDimension
   }
   const db = getMemoryDatabase()
diff --git a/models/memory/prompt.js b/models/memory/prompt.js
index 1e1460b..7093e26 100644
--- a/models/memory/prompt.js
+++ b/models/memory/prompt.js
@@ -24,6 +24,8 @@ function formatUserMemories (memories, config) {
     segments.push(header)
   }
   memories.forEach((item, index) => {
+    const timestamp = item.updated_at || item.created_at || ''
+    const timeSuffix = timestamp ? `（记录时间：${timestamp}）` : ''
     const context = {
       index,
       order: index + 1,
@@ -33,7 +35,10 @@ function formatUserMemories (memories, config) {
       sourceId: item.source_message_id || '',
       groupId: item.group_id || '',
       createdAt: item.created_at || '',
-      updatedAt: item.updated_at || ''
+      updatedAt: item.updated_at || '',
+      timestamp,
+      time: timestamp,
+      timeSuffix
     }
     const line = renderTemplate(itemTemplate, context)
     if (line) {
@@ -61,6 +66,8 @@ function formatGroupFacts (facts, config) {
   }
   facts.forEach((item, index) => {
     const topicSuffix = item.topic ? `（${item.topic}）` : ''
+    const timestamp = item.updated_at || item.created_at || ''
+    const timeSuffix = timestamp ? `（记录时间：${timestamp}）` : ''
     const context = {
       index,
       order: index + 1,
@@ -70,6 +77,9 @@ function formatGroupFacts (facts, config) {
       importance: item.importance ?? '',
       createdAt: item.created_at || '',
       updatedAt: item.updated_at || '',
+      timestamp,
+      time: timestamp,
+      timeSuffix,
       distance: item.distance ?? '',
       bm25: item.bm25_score ?? '',
       sourceMessages: item.source_messages || '',