PG 查看当前正在运行SQL的执行计划插件pg_show_plans

PG_SHOW_PLANS

下载

​​https://github.com/cybertec-postgresql/pg_show_plans​​

编译安装

cd postgresql-pg_version/contrib

tar zxvf pg_show_plans.tar.gz

cd pg_show_plans

make && make install 

配置插件

• 修改配置文件

 vim postgresql.conf
   shared_preload_libraries='pg_show_plans'

• 创建扩展

  psql -c "create extension pg_show_plans ;"

• 重启数据库服务

  pg_ctl restart

测试该插件

• 会话1

  test=# create table test(id int, name varchar);
  CREATE TABLE
  test=# insert into test select n, n||'name'  from generate_series(1,10000000)n;
  
  INSERT 0 10000000
  test=# 
  test=# 
  test=# 
  test=# select * from test where id>37;

• 会话2

 test=#  SELECT p.pid, p.level, p.plan, a.query FROM pg_show_plans p 
     LEFT JOIN pg_stat_activity a
     ON p.pid = a.pid AND p.level = 0  where  p.pid<>pg_backend_pid() ORDER BY p.pid, p.level ;
     pid  | level |                              plan                              |              query              
  -------+-------+----------------------------------------------------------------+---------------------------------
 30175 |     0 | Seq Scan on test  (cost=0.00..179053.25 rows=9998860 width=15)+| select * from test where id>37;
         |       |   Filter: (id > 37)                                            | 
  (1 row)