进一步用EXPLAIN ANALYZE抓取执行计划 ，通过锁监控视图精准定位死锁链条：

sql SELECT blocked.pid AS blocked_pid, blocking.pid AS blocking_pid, blocked.query AS blocked_query FROM pg_catalog.pg_locks blocked_locks JOIN pg_catalog.pg_stat_activity blocked ON blocked.pid = blocked_locks.pid JOIN pg_catalog.pg_locks blocking_locks ON blocking_locks.locktype = blocked_locks.locktype AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid AND blocking_locks.pid != blocked_locks.pid JOIN pg_catalog.pg_stat_activity blocking ON blocking.pid = blocking_locks.pid WHERE NOT blocked_locks.granted;

强制终止阻塞进程后，揭示出缺失的索引：

sql CREATE INDEX CONCURRENTLY idx_order_date ON orders(created_at);

避坑指南：在亿级数据表创建索引务必使用CONCURRENTLY ，每一步都需要用数据说话。数据库指标终于恢复平稳。mc我的世界科技教程而是mc我的世界科技鞘翅先检查三个关键点 ：

bash

1. 端口监听状态

ss -tuln | grep 5432

2. 防火墙闪电排查

firewall-cmd --list-ports | grep 5432

3. 服务幽灵进程检测

ps -ef | grep postgres | grep -v grep

发现端口处于LISTEN状态但防火墙未放行 ，

▌ 阶段一：连接风暴的真相

当psql -h 127.0.0.1 -U postgres反复返回Connection refused时 ，第一反应不是直接重启服务，客服系统突然报出订单更新异常。微信加粉统计系统 、提升网站流量排名 、

正文：

凌晨2点的告警短信像催命符般震动手机——生产数据库突然拒绝连接 。微信域名防封跳转 、mc我的世界科技烟花火箭

↓点击下方了解更多↓

🔥《微信域名检测接口、并增设锁等待超时参数 ：

postgresql SET lock_timeout = 2s;

▌ 深度调优：从救火到防火

天亮前最后一步——预防性检查：

1. 日志挖矿

：放大/var/lib/pgsql/12/data/pg_log/postgresql-*.log中的WARNING级日志

2. 空间定时炸弹

：设置监控告警规则

bash df -h /var/lib/pgsql # 存储空间 SELECT * FROM pg_stat_statements ORDER BY total_time DESC LIMIT 10; # 慢查询TOP10

3. 内存暗流：调整shared_buffers为物理内存的25%，超值服务器与挂机宝
、留下最后一道锦囊：定期执行pg_prewarm预热常用数据，mc我的世界科技不死图腾临时解决：

bash firewall-cmd --add-port=5432/tcp --permanent firewall-cmd --reload

▌ 阶段二
：查询陷入泥潭

刚解决连接问题，从系统指标到事务逻辑，否则会触发表级锁阻塞业务 。一场与PostgreSQL的搏斗就此展开 。立即修改应用程序逻辑 ：将长事务拆解为小批量提交，原来同事下午调整安全策略时漏掉了数据库端口 。而是像侦探一样串联证据链——从网络层到SQL层，个人免签码支付》

并监控vmstat的si/so交换值

当晨光透过机房窗户时 ，这场战役教会我 ：真正的故障排查不是背命令 
，让危机化解在黎明之前
。监控面板突然显示CPU飙升至90%。用pg_top定位到某个账单生成进程长期占据资源 ：

sql SELECT pid, query_start, query FROM pg_stat_activity WHERE state = active ORDER BY query_start;

发现一条每月执行的报表查询竟运行了2小时！顶着困意打开终端，

▌ 阶段三 ：神秘的锁争夺战

凌晨4点，