以Postgres10为例：
如下教程需要先安装这个组件：yum install postgresql10-contrib
安装完成后，然后，登录到pgsql，执行如下的一系列命令(以要审计db1为例)：
代码语言：javascript复制postgres=# create database db1 ;
postgres=# c db1 ;
db1=# create extension hstore;
db1=# create or replace function ef_alter() returns event_trigger as $$
declare
rec hstore;
begin
select hstore(pg_stat_activity.*) into rec from pg_stat_activity where pid=pg_backend_pid(); -- 记录pg_stat_activity的内容
insert into aud_alter (ctx) values (rec);
end;
$$ language plpgsql strict;
db1=# create event trigger e_alter on ddl_command_end when tag in ('ALTER TABLE') execute procedure ef_alter();
db1=# create table aud_alter(id serial primary key, crt_time timestamp default now(), ctx hstore);
### 测试
db1=# create table test(id int);
db1=# alter table test alter column id type int8;
db1=# x;
db1=# select * from aud_alter;
-[ RECORD 1 ]-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
id | 1
crt_time | 2018-07-29 13:20:14.783321
ctx | "pid"=>"32512", "datid"=>"16386", "query"=>"alter table test alter column id type int8;", "state"=>"active", "datname"=>"db1", "usename"=>"postgres", "usesysid"=>"10", "wait_event"=>NULL, "xact_start"=>"2018-07-29 13:40:12.142124 08", "backend_xid"=>"698", "client_addr"=>NULL, "client_port"=>"-1", "query_start"=>"2018-07-29 13:40:12.142124 08", "backend_type"=>"client backend", "backend_xmin"=>"698", "state_change"=>"2018-07-29 13:40:12.142128 08", "backend_start"=>"2018-07-29 13:38:50.710944 08", "client_hostname"=>NULL, "wait_event_type"=>NULL, "application_name"=>"psql"
db1=# x;
db1=# select each(ctx) from aud_alter where id=1;
each
-------------------------------------------------------
(pid,32512)
(datid,16386)
(query,"alter table test alter column id type int8;")
(state,active)
(datname,db1)
(usename,postgres)
(usesysid,10)
(wait_event,)
(xact_start,"2018-07-29 13:40:12.142124 08")
(backend_xid,698)
(client_addr,)
(client_port,-1)
(query_start,"2018-07-29 13:40:12.142124 08")
(backend_type,"client backend")
(backend_xmin,698)
(state_change,"2018-07-29 13:40:12.142128 08")
(backend_start,"2018-07-29 13:38:50.710944 08")
(client_hostname,)
(wait_event_type,)
(application_name,psql)
(20 rows)参考：德哥 https://yq.aliyun.com/articles/65362
