4.4、事务读一致性REPEATABLE READ

这种事务级别表示事务自始至终读取的数据都是一致的，如下所示

session1

postgres=# create table t_repeatable_read (id int,mc text);
NOTICE:  Replica identity is needed for shard table, please add to this table through "alter table" command.
CREATE TABLE
postgres=# insert into t_repeatable_read values(1,'tbase');
INSERT 0 1
postgres=# begin isolation level repeatable read ;
BEGIN
postgres=# select * from t_repeatable_read ;
 id |  mc   
----+-------
  1 | tbase
(1 row)

session2

postgres=# insert into t_repeatable_read values(1,'pgxz'); 
INSERT 0 1
postgres=# select * from t_repeatable_read;
 id |  mc   
----+-------
  1 | tbase
  1 | pgxz
(2 rows)

session1

postgres=# select * from t_repeatable_read ;
 id |  mc   
----+-------
  1 | tbase
(1 row)
postgres=#