创建序列

CREATE SEQUENCE if not exists test_mergetable_id_seq
INCREMENT 1
MINVALUE 1
MAXVALUE 999999999
START 1
CACHE 1;
//或者： 
create sequence if not exists test_mergetable_id_seq increment by 1 minvalue 1 no maxvalue start with 1; 

指定序列（给表的主键指定创建好的序列）

alter table test_mergetable alter column "i_id" set default nextval('test_mergetable_id_seq');

设置序列自增长从当前最大值开始

SELECT setval('test_mergetable_id_seq', (SELECT MAX(i_id) FROM test_mergetable));
alter sequence test_mergetable_id_seq start with 12;

删除序列

drop sequence IF EXISTS test_mergetable_id_seq

查看序列

SELECT nextval('test_mergetable_id_seq')

补充：pgsql的schema对用户授权，单个用户跨schema增删改查操作

--创建用户

create user user1;

--修改密码

alter user report with password 'password';

--授权查询权限

grant usage on schema schema1 to user1;
grant usage on schema schema2 to user1;

修改search_path可跨schema操作

set search_path = "$user",user1,user2

--授权schema:schema1给user1权限 这个权限太大需要慎用

grant all on schema schema1 to user1;

--授权schema的表权限给user1 用户权限太多需慎用

grant all on all tables in schema schema1 to user1;

--授权schema的表权限给user1 用户权限太多需慎用

grant all on all tables in schema schema1 to user1;

--授权某个schema的单个表查权限

grant select on schema2.table1           to user1;

--收回所有授权

revoke all on all tables in schema schema1 from user1;

--为某个特定用户设置search_path

alter user user1 set search_path="$user",user1,user2;

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。如有错误或未考虑完全的地方，望不吝赐教。