整理文档

postgresql_and_edb/postgresql锁表查询.md

@@ -1,4 +1,4 @@
-```
+```postgresql
 SELECT locker.pid,
        pc.relname,
        locker.mode,
@@ -27,12 +27,18 @@ SELECT pg_terminate_backend(14448)
 
 
 
-```
-playboy=> select pg_size_pretty(pg_total_relation_size('test'));   //查看表的总大小，包括索引大小  
- pg_size_pretty  
+```postgresql
+-- 查看表的总大小，包括索引大小  
+select pg_size_pretty(pg_total_relation_size('test')); 
 
- playboy=> select pg_size_pretty(pg_relation_size('test'));   //以KB，MB，GB的方式来查看表大小  
- pg_size_pretty  
+-- 以KB，MB，GB的方式来查看表大小
+select pg_size_pretty(pg_relation_size('test'));     
+
+-- 查看最大连接数
+show max_connections;
+
+-- 查看当前连接数
+SELECT COUNT(*) from pg_stat_activity;
 
 
 ```