diff --git a/internal/constants/constants.go b/internal/constants/constants.go
index 2814e9b..2e35b27 100644
--- a/internal/constants/constants.go
+++ b/internal/constants/constants.go
@@ -41,6 +41,12 @@ var (
 	// 单位常量
 	KB int64 = 1024
 	MB int64 = 1024 * KB
+
+	// 不同类型数据的保留时间
+	MetricsRetention = 90 * 24 * time.Hour // 基础指标保留90天
+	StatusRetention  = 30 * 24 * time.Hour // 状态码统计保留30天
+	PathRetention    = 7 * 24 * time.Hour  // 路径统计保留7天
+	RefererRetention = 7 * 24 * time.Hour  // 引用来源保留7天
 )
 
 // UpdateFromConfig 从配置文件更新常量
diff --git a/internal/handler/metrics.go b/internal/handler/metrics.go
index 54b1252..f8c6c53 100644
--- a/internal/handler/metrics.go
+++ b/internal/handler/metrics.go
@@ -392,6 +392,7 @@ var metricsTemplate = `
 +           gap: 20px;
 +           align-items: center;
 +           flex-wrap: wrap;
++           padding: 10px;
 +       }
 +       
 +       #statusCodes .metric {
@@ -404,6 +405,8 @@ var metricsTemplate = `
 +           border-radius: 20px;
 +           margin: 0;
 +           border: none;
++           min-width: 100px;
++           justify-content: space-between;
 +       }
 +       
         .status-badge {
@@ -929,7 +932,7 @@ var metricsTemplate = `
             btn.addEventListener('click', function() {
                 document.querySelectorAll('.time-btn').forEach(b => b.classList.remove('active'));
                 this.classList.add('active');
-                loadHistoryData(parseInt(this.dataset.hours));
+                loadHistoryData(parseFloat(this.dataset.hours));
             });
         });
 
@@ -1069,15 +1072,14 @@ func (h *ProxyHandler) MetricsAuthHandler(w http.ResponseWriter, r *http.Request
 
 // 添加历史数据查询接口
 func (h *ProxyHandler) MetricsHistoryHandler(w http.ResponseWriter, r *http.Request) {
-	hours := 24 // 默认24小时
-	if h := r.URL.Query().Get("hours"); h != "" {
-		if parsed, err := strconv.Atoi(h); err == nil && parsed > 0 {
-			hours = parsed
-		}
+	hours := r.URL.Query().Get("hours")
+	hoursFloat, err := strconv.ParseFloat(hours, 64)
+	if err != nil {
+		hoursFloat = 24.0
 	}
 
 	collector := metrics.GetCollector()
-	metrics, err := collector.GetDB().GetRecentMetrics(hours)
+	metrics, err := collector.GetDB().GetRecentMetrics(hoursFloat)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
diff --git a/internal/handler/proxy.go b/internal/handler/proxy.go
index ad6670d..7a5ea33 100644
--- a/internal/handler/proxy.go
+++ b/internal/handler/proxy.go
@@ -228,7 +228,12 @@ func (h *ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			http.Error(w, "Error reading response", http.StatusInternalServerError)
 			return
 		}
-		written, _ := w.Write(body)
+		written, err := w.Write(body)
+		if err != nil {
+			if !isConnectionClosed(err) {
+				log.Printf("Error writing response: %v", err)
+			}
+		}
 		collector.RecordRequest(r.URL.Path, resp.StatusCode, time.Since(start), int64(written), utils.GetClientIP(r), r)
 	} else {
 		// 大响应使用流式传输
@@ -288,3 +293,13 @@ func copyHeader(dst, src http.Header) {
 		}
 	}
 }
+
+// 添加辅助函数判断是否是连接关闭错误
+func isConnectionClosed(err error) bool {
+	if err == nil {
+		return false
+	}
+	return strings.Contains(err.Error(), "broken pipe") ||
+		strings.Contains(err.Error(), "connection reset by peer") ||
+		strings.Contains(err.Error(), "protocol wrong type for socket")
+}
diff --git a/internal/metrics/collector.go b/internal/metrics/collector.go
index b36848a..81d302b 100644
--- a/internal/metrics/collector.go
+++ b/internal/metrics/collector.go
@@ -1,6 +1,7 @@
 package metrics
 
 import (
+	"database/sql"
 	"fmt"
 	"log"
 	"net/http"
@@ -69,6 +70,11 @@ func InitCollector(dbPath string, config *config.Config) error {
 			lastMetrics.TotalRequests, lastMetrics.TotalErrors, lastMetrics.TotalBytes)
 	}
 
+	// 加载最近5分钟的统计数据
+	if err := globalCollector.LoadRecentStats(); err != nil {
+		log.Printf("Warning: Failed to load recent stats: %v", err)
+	}
+
 	globalCollector.cache = cache.NewCache(constants.CacheTTL)
 	globalCollector.monitor = monitor.NewMonitor()
 
@@ -274,10 +280,11 @@ func (c *Collector) GetStats() map[string]interface{} {
 
 	// 延迟指标
 	currentTotalRequests := atomic.LoadInt64(&c.totalRequests)
-	if currentTotalRequests > 0 {
-		stats["avg_latency"] = c.latencySum.Load() / currentTotalRequests
-	} else {
+	latencySum := c.latencySum.Load()
+	if currentTotalRequests <= 0 || latencySum <= 0 {
 		stats["avg_latency"] = int64(0)
+	} else {
+		stats["avg_latency"] = latencySum / currentTotalRequests
 	}
 
 	// 状态码统计
@@ -300,7 +307,7 @@ func (c *Collector) GetStats() map[string]interface{} {
 			Path:             key.(string),
 			RequestCount:     stats.Requests.Load(),
 			ErrorCount:       stats.Errors.Load(),
-			AvgLatency:       FormatDuration(time.Duration(stats.LatencySum.Load() / stats.Requests.Load())),
+			AvgLatency:       formatAvgLatency(stats.LatencySum.Load(), stats.Requests.Load()),
 			BytesTransferred: stats.Bytes.Load(),
 		})
 		return true
@@ -441,3 +448,141 @@ func (c *Collector) SaveMetrics(stats map[string]interface{}) error {
 
 	return c.db.SaveMetrics(stats)
 }
+
+// LoadRecentStats 加载最近的统计数据
+func (c *Collector) LoadRecentStats() error {
+	// 加载最近5分钟的数据
+	row := c.db.DB.QueryRow(`
+		SELECT 
+			total_requests, total_errors, total_bytes, avg_latency
+		FROM metrics_history 
+		WHERE timestamp >= datetime('now', '-5', 'minutes')
+		ORDER BY timestamp DESC 
+		LIMIT 1
+	`)
+
+	var metrics models.HistoricalMetrics
+	if err := row.Scan(
+		&metrics.TotalRequests,
+		&metrics.TotalErrors,
+		&metrics.TotalBytes,
+		&metrics.AvgLatency,
+	); err != nil && err != sql.ErrNoRows {
+		return err
+	}
+
+	// 更新持久化数据
+	if metrics.TotalRequests > 0 {
+		c.persistentStats.totalRequests.Store(metrics.TotalRequests)
+		c.persistentStats.totalErrors.Store(metrics.TotalErrors)
+		c.persistentStats.totalBytes.Store(metrics.TotalBytes)
+	}
+
+	// 加载状态码统计
+	rows, err := c.db.DB.Query(`
+		SELECT status_group, SUM(count) as count 
+		FROM status_code_history 
+		WHERE timestamp >= datetime('now', '-5', 'minutes')
+		GROUP BY status_group
+	`)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var group string
+		var count int64
+		if err := rows.Scan(&group, &count); err != nil {
+			return err
+		}
+		if len(group) > 0 {
+			idx := (int(group[0]) - '0') - 1
+			if idx >= 0 && idx < len(c.statusStats) {
+				c.statusStats[idx].Store(count)
+			}
+		}
+	}
+
+	if err := rows.Err(); err != nil {
+		return fmt.Errorf("error scanning status code rows: %v", err)
+	}
+
+	// 加载路径统计
+	rows, err = c.db.DB.Query(`
+		SELECT 
+			path, 
+			SUM(request_count) as requests,
+			SUM(error_count) as errors,
+			AVG(bytes_transferred) as bytes,
+			AVG(avg_latency) as latency
+		FROM popular_paths_history
+		WHERE timestamp >= datetime('now', '-5', 'minutes')
+		GROUP BY path
+		ORDER BY requests DESC
+		LIMIT 10
+	`)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var path string
+		var requests, errors, bytes int64
+		var latency float64
+		if err := rows.Scan(&path, &requests, &errors, &bytes, &latency); err != nil {
+			return err
+		}
+		stats := &models.PathStats{}
+		stats.Requests.Store(requests)
+		stats.Errors.Store(errors)
+		stats.Bytes.Store(bytes)
+		stats.LatencySum.Store(int64(latency))
+		c.pathStats.Store(path, stats)
+	}
+
+	if err := rows.Err(); err != nil {
+		return fmt.Errorf("error scanning path stats rows: %v", err)
+	}
+
+	// 加载引用来源统计
+	rows, err = c.db.DB.Query(`
+		SELECT 
+			referer,
+			SUM(request_count) as requests
+		FROM referer_history
+		WHERE timestamp >= datetime('now', '-5', 'minutes')
+		GROUP BY referer
+		ORDER BY requests DESC
+		LIMIT 10
+	`)
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var referer string
+		var requests int64
+		if err := rows.Scan(&referer, &requests); err != nil {
+			return err
+		}
+		stats := &models.PathStats{}
+		stats.Requests.Store(requests)
+		c.refererStats.Store(referer, stats)
+	}
+
+	if err := rows.Err(); err != nil {
+		return fmt.Errorf("error scanning referer stats rows: %v", err)
+	}
+
+	return nil
+}
+
+func formatAvgLatency(latencySum, requests int64) string {
+	if requests <= 0 || latencySum <= 0 {
+		return "0 ms"
+	}
+	return FormatDuration(time.Duration(latencySum / requests))
+}
diff --git a/internal/models/metrics.go b/internal/models/metrics.go
index da87c2a..750de89 100644
--- a/internal/models/metrics.go
+++ b/internal/models/metrics.go
@@ -46,7 +46,13 @@ type PathMetrics struct {
 }
 
 type MetricsDB struct {
-	DB *sql.DB
+	DB    *sql.DB
+	stats struct {
+		queries     atomic.Int64
+		slowQueries atomic.Int64
+		errors      atomic.Int64
+		lastError   atomic.Value // string
+	}
 }
 
 type PerformanceMetrics struct {
@@ -68,11 +74,21 @@ func NewMetricsDB(dbPath string) (*MetricsDB, error) {
 	db.SetConnMaxLifetime(time.Hour)
 
 	// 设置数据库优化参数
-	db.Exec("PRAGMA busy_timeout = 5000")  // 设置忙等待超时
-	db.Exec("PRAGMA journal_mode = WAL")   // 使用 WAL 模式提高并发性能
-	db.Exec("PRAGMA synchronous = NORMAL") // 在保证安全的前提下提高性能
-	db.Exec("PRAGMA cache_size = -2000")   // 使用2MB缓存
-	db.Exec("PRAGMA temp_store = MEMORY")  // 临时表使用内存
+	if _, err := db.Exec("PRAGMA busy_timeout = 5000"); err != nil {
+		return nil, fmt.Errorf("failed to set busy_timeout: %v", err)
+	}
+	if _, err := db.Exec("PRAGMA journal_mode = WAL"); err != nil {
+		return nil, fmt.Errorf("failed to set journal_mode: %v", err)
+	}
+	if _, err := db.Exec("PRAGMA synchronous = NORMAL"); err != nil {
+		return nil, fmt.Errorf("failed to set synchronous: %v", err)
+	}
+	if _, err := db.Exec("PRAGMA cache_size = -2000"); err != nil {
+		return nil, fmt.Errorf("failed to set cache_size: %v", err)
+	}
+	if _, err := db.Exec("PRAGMA temp_store = MEMORY"); err != nil {
+		return nil, fmt.Errorf("failed to set temp_store: %v", err)
+	}
 
 	// 创建必要的表
 	if err := initTables(db); err != nil {
@@ -80,11 +96,13 @@ func NewMetricsDB(dbPath string) (*MetricsDB, error) {
 		return nil, err
 	}
 
-	return &MetricsDB{DB: db}, nil
+	mdb := &MetricsDB{DB: db}
+	mdb.stats.lastError.Store("")
+	return mdb, nil
 }
 
 func initTables(db *sql.DB) error {
-	// 创建指标历史表
+	// 创指标历史表
 	_, err := db.Exec(`
 		CREATE TABLE IF NOT EXISTS metrics_history (
 			id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -135,7 +153,7 @@ func initTables(db *sql.DB) error {
 		CREATE INDEX IF NOT EXISTS idx_status_timestamp ON status_stats(timestamp);
 		CREATE INDEX IF NOT EXISTS idx_path_timestamp ON path_stats(timestamp);
 
-		-- 复合索引，用于优化聚合查询
+		-- 复合引，用于优化聚合查询
 		CREATE INDEX IF NOT EXISTS idx_metrics_timestamp_values ON metrics_history(
 			timestamp,
 			total_requests,
@@ -163,7 +181,7 @@ func initTables(db *sql.DB) error {
 	}
 
 	// 添加新的表
-	_, err = db.Exec(`
+	if _, err := db.Exec(`
 		-- 性能指标表
 		CREATE TABLE IF NOT EXISTS performance_metrics (
 			id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -205,7 +223,36 @@ func initTables(db *sql.DB) error {
 		CREATE INDEX IF NOT EXISTS idx_status_code_history_timestamp ON status_code_history(timestamp);
 		CREATE INDEX IF NOT EXISTS idx_popular_paths_history_timestamp ON popular_paths_history(timestamp);
 		CREATE INDEX IF NOT EXISTS idx_referer_history_timestamp ON referer_history(timestamp);
-	`)
+	`); err != nil {
+		return err
+	}
+
+	// 添加新的索引
+	if _, err := db.Exec(`
+		-- 为性能指标表添加复合索引
+		CREATE INDEX IF NOT EXISTS idx_performance_metrics_composite ON performance_metrics(
+			timestamp,
+			avg_response_time,
+			requests_per_second,
+			bytes_per_second
+		);
+
+		-- 为状态码历史表添加复合索引
+		CREATE INDEX IF NOT EXISTS idx_status_code_history_composite ON status_code_history(
+			timestamp,
+			status_group,
+			count
+		);
+
+		-- 为热门路径历史表添加复合索引
+		CREATE INDEX IF NOT EXISTS idx_popular_paths_history_composite ON popular_paths_history(
+			timestamp,
+			path,
+			request_count
+		);
+	`); err != nil {
+		return err
+	}
 
 	// 启动定期清理任务
 	go cleanupRoutine(db)
@@ -226,7 +273,10 @@ func cleanupRoutine(db *sql.DB) {
 		// 检查数据库大小
 		var dbSize int64
 		row := db.QueryRow("SELECT page_count * page_size FROM pragma_page_count, pragma_page_size")
-		row.Scan(&dbSize)
+		if err := row.Scan(&dbSize); err != nil {
+			log.Printf("Error getting database size: %v", err)
+			continue
+		}
 		log.Printf("Current database size: %s", FormatBytes(uint64(dbSize)))
 
 		tx, err := db.Begin()
@@ -236,33 +286,49 @@ func cleanupRoutine(db *sql.DB) {
 		}
 
 		// 优化清理性能
-		tx.Exec("PRAGMA synchronous = NORMAL")
-		tx.Exec("PRAGMA journal_mode = WAL")
-		tx.Exec("PRAGMA temp_store = MEMORY")
-		tx.Exec("PRAGMA cache_size = -2000")
-
-		// 先清理索引
-		tx.Exec("ANALYZE")
-		tx.Exec("PRAGMA optimize")
-
-		cutoff := time.Now().Add(-constants.DataRetention)
-		tables := []string{
-			"metrics_history",
-			"status_stats",
-			"path_stats",
-			"performance_metrics",
-			"status_code_history",
-			"popular_paths_history",
-			"referer_history",
+		if _, err := tx.Exec("PRAGMA synchronous = NORMAL"); err != nil {
+			log.Printf("Error setting synchronous mode: %v", err)
+		}
+		if _, err := tx.Exec("PRAGMA journal_mode = WAL"); err != nil {
+			log.Printf("Error setting journal mode: %v", err)
+		}
+		if _, err := tx.Exec("PRAGMA temp_store = MEMORY"); err != nil {
+			log.Printf("Error setting temp store: %v", err)
+		}
+		if _, err := tx.Exec("PRAGMA cache_size = -2000"); err != nil {
+			log.Printf("Error setting cache size: %v", err)
 		}
 
-		for _, table := range tables {
-			// 使用批量删除提高性能
+		// 先清理索引
+		if _, err := tx.Exec("ANALYZE"); err != nil {
+			log.Printf("Error running ANALYZE: %v", err)
+		}
+		if _, err := tx.Exec("PRAGMA optimize"); err != nil {
+			log.Printf("Error running optimize: %v", err)
+		}
+
+		// 使用不同的保留时间清理不同类型的数据
+		cleanupTables := []struct {
+			table     string
+			retention time.Duration
+		}{
+			{"metrics_history", constants.MetricsRetention},
+			{"performance_metrics", constants.MetricsRetention},
+			{"status_code_history", constants.StatusRetention},
+			{"status_stats", constants.StatusRetention},
+			{"popular_paths_history", constants.PathRetention},
+			{"path_stats", constants.PathRetention},
+			{"referer_history", constants.RefererRetention},
+		}
+
+		for _, t := range cleanupTables {
+			cutoff := time.Now().Add(-t.retention)
+			// 使用批删除提高性能
 			for {
-				result, err := tx.Exec(`DELETE FROM `+table+` WHERE timestamp < ? LIMIT 1000`, cutoff)
+				result, err := tx.Exec(`DELETE FROM `+t.table+` WHERE timestamp < ? LIMIT 1000`, cutoff)
 				if err != nil {
 					tx.Rollback()
-					log.Printf("Error cleaning %s: %v", table, err)
+					log.Printf("Error cleaning %s: %v", t.table, err)
 					break
 				}
 				rows, _ := result.RowsAffected()
@@ -276,9 +342,15 @@ func cleanupRoutine(db *sql.DB) {
 		if err := tx.Commit(); err != nil {
 			log.Printf("Error committing cleanup transaction: %v", err)
 		} else {
-			log.Printf("Cleaned up %d old records in %v, freed %s",
-				totalDeleted, time.Since(start),
-				FormatBytes(uint64(dbSize-getDBSize(db))))
+			newSize := getDBSize(db)
+			if newSize == 0 {
+				log.Printf("Cleaned up %d old records in %v, but failed to get new DB size",
+					totalDeleted, time.Since(start))
+			} else {
+				log.Printf("Cleaned up %d old records in %v, freed %s",
+					totalDeleted, time.Since(start),
+					FormatBytes(uint64(dbSize-newSize)))
+			}
 		}
 	}
 }
@@ -287,7 +359,10 @@ func cleanupRoutine(db *sql.DB) {
 func getDBSize(db *sql.DB) int64 {
 	var size int64
 	row := db.QueryRow("SELECT page_count * page_size FROM pragma_page_count, pragma_page_size")
-	row.Scan(&size)
+	if err := row.Scan(&size); err != nil {
+		log.Printf("Error getting database size: %v", err)
+		return 0
+	}
 	return size
 }
 
@@ -298,68 +373,59 @@ func (db *MetricsDB) SaveMetrics(stats map[string]interface{}) error {
 	}
 	defer tx.Rollback()
 
-	// 保存基础指标
-	_, err = tx.Exec(`
-		INSERT INTO metrics_history (
-			total_requests, total_errors, total_bytes, avg_latency
-		) VALUES (?, ?, ?, ?)`,
-		stats["total_requests"], stats["total_errors"],
-		stats["total_bytes"], stats["avg_latency"],
-	)
-	if err != nil {
-		return err
+	// 设置事务优化参数
+	if _, err := tx.Exec("PRAGMA synchronous = NORMAL"); err != nil {
+		return fmt.Errorf("failed to set synchronous mode: %v", err)
+	}
+	if _, err := tx.Exec("PRAGMA journal_mode = WAL"); err != nil {
+		return fmt.Errorf("failed to set journal mode: %v", err)
 	}
 
-	// 保存状态码统计
-	statusStats := stats["status_code_stats"].(map[string]int64)
+	// 使用预处理语句提高性能
 	stmt, err := tx.Prepare(`
-		INSERT INTO status_stats (status_group, count)
-		VALUES (?, ?)
-	`)
-	if err != nil {
-		return err
-	}
-	defer stmt.Close()
-
-	for group, count := range statusStats {
-		if _, err := stmt.Exec(group, count); err != nil {
-			return err
-		}
-	}
-
-	// 保存路径统计
-	pathStats := stats["top_paths"].([]PathMetrics)
-	stmt, err = tx.Prepare(`
-		INSERT INTO path_stats (
-			path, requests, errors, bytes, avg_latency
+		INSERT INTO metrics_history (
+			total_requests, total_errors, total_bytes, avg_latency, error_rate
 		) VALUES (?, ?, ?, ?, ?)
 	`)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to prepare statement: %v", err)
+	}
+	defer stmt.Close()
+
+	// 类型断言检查
+	totalReqs, ok := stats["total_requests"].(int64)
+	if !ok {
+		return fmt.Errorf("invalid total_requests type")
+	}
+	totalErrs, ok := stats["total_errors"].(int64)
+	if !ok {
+		return fmt.Errorf("invalid total_errors type")
+	}
+	totalBytes, ok := stats["total_bytes"].(int64)
+	if !ok {
+		return fmt.Errorf("invalid total_bytes type")
+	}
+	avgLatency, ok := stats["avg_latency"].(float64)
+	if !ok {
+		return fmt.Errorf("invalid avg_latency type")
 	}
 
-	for _, p := range pathStats {
-		if _, err := stmt.Exec(
-			p.Path, p.RequestCount, p.ErrorCount,
-			p.BytesTransferred, p.AvgLatency,
-		); err != nil {
-			return err
-		}
+	// 计算错误率
+	var errorRate float64
+	if totalReqs > 0 {
+		errorRate = float64(totalErrs) / float64(totalReqs)
 	}
 
-	// 同时保存性能指标
-	_, err = tx.Exec(`
-		INSERT INTO performance_metrics (
-			avg_response_time,
-			requests_per_second,
-			bytes_per_second
-		) VALUES (?, ?, ?)`,
-		stats["avg_latency"],
-		stats["requests_per_second"],
-		stats["bytes_per_second"],
+	// 保存基础指标
+	_, err = stmt.Exec(
+		totalReqs,
+		totalErrs,
+		totalBytes,
+		int64(avgLatency),
+		errorRate,
 	)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to save metrics: %v", err)
 	}
 
 	return tx.Commit()
@@ -369,68 +435,107 @@ func (db *MetricsDB) Close() error {
 	return db.DB.Close()
 }
 
-func (db *MetricsDB) GetRecentMetrics(hours int) ([]HistoricalMetrics, error) {
-	// 设置查询优化参数
-	db.DB.Exec("PRAGMA temp_store = MEMORY")
-	db.DB.Exec("PRAGMA cache_size = -4000")    // 使用4MB缓存
-	db.DB.Exec("PRAGMA mmap_size = 268435456") // 使用256MB内存映射
-
-	var interval string
-	if hours <= 24 {
-		if hours <= 1 {
-			interval = "%Y-%m-%d %H:%M:00" // 按分钟分组
-		} else {
-			interval = "%Y-%m-%d %H:00:00" // 按小时分组
-		}
-	} else if hours <= 168 {
-		interval = "%Y-%m-%d %H:00:00" // 按小时分组
-	} else {
-		interval = "%Y-%m-%d 00:00:00" // 按天分组
+func (db *MetricsDB) GetRecentMetrics(hours float64) ([]HistoricalMetrics, error) {
+	start := time.Now()
+	var queryStats struct {
+		rowsProcessed int
+		cacheHits     int64
+		cacheSize     int64
 	}
 
-	// 修改查询逻辑，使用窗口函数计算差值
+	// 设置查询优化参数
+	tx, err := db.DB.Begin()
+	if err != nil {
+		return nil, fmt.Errorf("failed to begin transaction: %v", err)
+	}
+	defer tx.Rollback()
+
+	if _, err := tx.Exec("PRAGMA temp_store = MEMORY"); err != nil {
+		return nil, fmt.Errorf("failed to set temp_store: %v", err)
+	}
+	if _, err := tx.Exec("PRAGMA cache_size = -4000"); err != nil {
+		return nil, fmt.Errorf("failed to set cache_size: %v", err)
+	}
+	if _, err := tx.Exec("PRAGMA mmap_size = 268435456"); err != nil {
+		return nil, fmt.Errorf("failed to set mmap_size: %v", err)
+	}
+
+	if err := tx.Commit(); err != nil {
+		return nil, fmt.Errorf("failed to commit transaction: %v", err)
+	}
+
+	// 计算查询时间范围
+	endTime := time.Now()
+	startTime := endTime.Add(-time.Duration(hours * float64(time.Hour.Nanoseconds())))
+
+	// 格式化时间
+	startTimeStr := startTime.Format("2006-01-02 15:04:05")
+	endTimeStr := endTime.Format("2006-01-02 15:04:05")
+
+	// 处理小于1小时的情况
+	if hours <= 0 {
+		hours = 0.5 // 30分钟
+	}
+
+	// 计算合适的时间间隔
+	var interval string
+	var timeStep int
+	switch {
+	case hours <= 0.5: // 30分钟
+		interval = "%Y-%m-%d %H:%M:00"
+		timeStep = 1 // 1分钟
+	case hours <= 1:
+		interval = "%Y-%m-%d %H:%M:00"
+		timeStep = 1 // 1分钟
+	case hours <= 24:
+		interval = "%Y-%m-%d %H:%M:00"
+		timeStep = 5 // 5分钟
+	case hours <= 168:
+		interval = "%Y-%m-%d %H:00:00"
+		timeStep = 60 // 1小时
+	default:
+		interval = "%Y-%m-%d 00:00:00"
+		timeStep = 1440 // 1天
+	}
+
+	// 获取查询统计
+	row := db.DB.QueryRow("SELECT cache_hits, cache_misses, cache_size FROM pragma_stats")
+	var cacheMisses int64
+	row.Scan(&queryStats.cacheHits, &cacheMisses, &queryStats.cacheSize)
+
+	// 修改查询逻辑
 	rows, err := db.DB.Query(`
-		WITH time_series AS (
-			-- 生成时间序列
-			SELECT datetime('now', 'localtime') - 
-				   (CASE 
-						WHEN ?2 <= 24 THEN (300 * n) -- 5分钟间隔
-						WHEN ?2 <= 168 THEN (3600 * n) -- 1小时间隔
-						ELSE (86400 * n) -- 1天间隔
-					END) AS time_point
-			FROM (
-				SELECT ROW_NUMBER() OVER () - 1 as n
-				FROM metrics_history
-				LIMIT (CASE 
-					WHEN ?2 <= 24 THEN ?2 * 12 -- 5分钟间隔
-					WHEN ?2 <= 168 THEN ?2 -- 1小时间隔
-					ELSE ?2 / 24 -- 1天间隔
-				END)
-			)
-			WHERE time_point >= datetime('now', '-' || ?2 || ' hours', 'localtime')
-			  AND time_point <= datetime('now', 'localtime')
+		WITH RECURSIVE 
+		time_series(time_point) AS (
+			SELECT datetime(?, 'localtime')
+			UNION ALL
+			SELECT datetime(time_point, '-' || ? || ' minutes')
+			FROM time_series
+			WHERE time_point > datetime(?, 'localtime')
+			LIMIT 1000
 		),
 		grouped_metrics AS (
 			SELECT 
-				strftime(?1, timestamp, 'localtime') as group_time,
+				strftime(?, timestamp, 'localtime') as group_time,
 				MAX(total_requests) as period_requests,
 				MAX(total_errors) as period_errors,
 				MAX(total_bytes) as period_bytes,
 				AVG(avg_latency) as avg_latency
 			FROM metrics_history
-			WHERE timestamp >= datetime('now', '-' || ?2 || ' hours', 'localtime')
+			WHERE timestamp BETWEEN ? AND ?
 			GROUP BY group_time
 		)
 		SELECT 
-			strftime(?1, ts.time_point, 'localtime') as timestamp,
+			strftime(?, ts.time_point, 'localtime') as timestamp,
 			COALESCE(m.period_requests - LAG(m.period_requests, 1) OVER (ORDER BY ts.time_point), 0) as total_requests,
 			COALESCE(m.period_errors - LAG(m.period_errors, 1) OVER (ORDER BY ts.time_point), 0) as total_errors,
 			COALESCE(m.period_bytes - LAG(m.period_bytes, 1) OVER (ORDER BY ts.time_point), 0) as total_bytes,
 			COALESCE(m.avg_latency, 0) as avg_latency
 		FROM time_series ts
-		LEFT JOIN grouped_metrics m ON strftime(?1, ts.time_point, 'localtime') = m.group_time
+		LEFT JOIN grouped_metrics m ON strftime(?, ts.time_point, 'localtime') = m.group_time
 		ORDER BY timestamp DESC
-	`, interval, hours)
+		LIMIT 1000
+	`, endTimeStr, timeStep, startTimeStr, interval, startTimeStr, endTimeStr, interval)
 	if err != nil {
 		return nil, err
 	}
@@ -468,6 +573,15 @@ func (db *MetricsDB) GetRecentMetrics(hours int) ([]HistoricalMetrics, error) {
 		metrics = append(metrics, m)
 	}
 
+	// 记录查询性能
+	duration := time.Since(start)
+	if duration > time.Second {
+		log.Printf("Slow query warning: GetRecentMetrics(%v hours) took %v "+
+			"(rows: %d, cache hits: %d, cache size: %s)",
+			hours, duration, queryStats.rowsProcessed,
+			queryStats.cacheHits, FormatBytes(uint64(queryStats.cacheSize)))
+	}
+
 	// 如果没有数据，返回一个空的记录
 	if len(metrics) == 0 {
 		now := time.Now()
@@ -485,6 +599,7 @@ func (db *MetricsDB) GetRecentMetrics(hours int) ([]HistoricalMetrics, error) {
 }
 
 func (db *MetricsDB) SaveFullMetrics(stats map[string]interface{}) error {
+	start := time.Now()
 	tx, err := db.DB.Begin()
 	if err != nil {
 		return err
@@ -495,40 +610,26 @@ func (db *MetricsDB) SaveFullMetrics(stats map[string]interface{}) error {
 	startSize := getDBSize(db.DB)
 
 	// 优化写入性能
-	tx.Exec("PRAGMA synchronous = NORMAL")
-	tx.Exec("PRAGMA journal_mode = WAL")
-	tx.Exec("PRAGMA temp_store = MEMORY")
-	tx.Exec("PRAGMA cache_size = -2000") // 使用2MB缓存
-
-	// 使用批量插入提高性能
-	const batchSize = 100
-
-	// 预分配语句
-	stmts := make([]*sql.Stmt, 0, 4)
-	defer func() {
-		for _, stmt := range stmts {
-			stmt.Close()
-		}
-	}()
-
-	// 保存性能指标
-	_, err = tx.Exec(`
-		INSERT INTO performance_metrics (
-			avg_response_time,
-			requests_per_second,
-			bytes_per_second
-		) VALUES (?, ?, ?)`,
-		stats["avg_latency"],
-		stats["requests_per_second"],
-		stats["bytes_per_second"],
-	)
-	if err != nil {
-		return err
+	if _, err := tx.Exec("PRAGMA synchronous = NORMAL"); err != nil {
+		return fmt.Errorf("failed to set synchronous mode: %v", err)
+	}
+	if _, err := tx.Exec("PRAGMA journal_mode = WAL"); err != nil {
+		return fmt.Errorf("failed to set journal mode: %v", err)
+	}
+	if _, err := tx.Exec("PRAGMA temp_store = MEMORY"); err != nil {
+		return fmt.Errorf("failed to set temp store: %v", err)
+	}
+	if _, err := tx.Exec("PRAGMA cache_size = -2000"); err != nil {
+		return fmt.Errorf("failed to set cache size: %v", err)
 	}
 
 	// 使用事务提高写入性能
-	tx.Exec("PRAGMA synchronous = OFF")
-	tx.Exec("PRAGMA journal_mode = MEMORY")
+	if _, err := tx.Exec("PRAGMA synchronous = OFF"); err != nil {
+		return fmt.Errorf("failed to set synchronous mode: %v", err)
+	}
+	if _, err := tx.Exec("PRAGMA journal_mode = MEMORY"); err != nil {
+		return fmt.Errorf("failed to set journal mode: %v", err)
+	}
 
 	// 保存状态码统计
 	statusStats := stats["status_code_stats"].(map[string]int64)
@@ -589,10 +690,14 @@ func (db *MetricsDB) SaveFullMetrics(stats map[string]interface{}) error {
 		return err
 	}
 
-	// 记录写入的数据量
+	// 记录写入的数据量和性能
 	endSize := getDBSize(db.DB)
-	log.Printf("Saved metrics: wrote %s to database",
-		FormatBytes(uint64(endSize-startSize)))
+	duration := time.Since(start)
+	log.Printf("Saved metrics: wrote %s to database in %v (%.2f MB/s)",
+		FormatBytes(uint64(endSize-startSize)),
+		duration,
+		float64(endSize-startSize)/(1024*1024)/duration.Seconds(),
+	)
 
 	return nil
 }
@@ -676,3 +781,12 @@ func FormatBytes(bytes uint64) string {
 		return fmt.Sprintf("%d Bytes", bytes)
 	}
 }
+
+func (db *MetricsDB) GetStats() map[string]interface{} {
+	return map[string]interface{}{
+		"total_queries": db.stats.queries.Load(),
+		"slow_queries":  db.stats.slowQueries.Load(),
+		"total_errors":  db.stats.errors.Load(),
+		"last_error":    db.stats.lastError.Load(),
+	}
+}