4.2、提交事务

进程#1访问

postgres=# begin;
BEGIN
postgres=# delete from tbase where id=5;
DELETE 1
postgres=#
postgres=# select * from tbase order by id;
 id |   nickname    
----+---------------
  1 | hello TBase
  2 | TBase好
  3 | TBase好
  4 | TBase default

TBase也是完全支持ACID特性，没提交前开启另一个连接查询，你会看到是5条记录，这是TBase隔离性和多版本视图的实现，如下所示

进程#2访问

postgres=# select * from tbase order by id;
 id |   nickname    
----+---------------
  1 | hello TBase
  2 | TBase好
  3 | TBase好
  4 | TBase default
  5 | TBase swap
(5 rows)

进程#1提交数据

postgres=# commit;
COMMIT
postgres=# 

进程#2再查询数据，这时能看到已经提交的数据了，这个级别叫“读已提交”

postgres=# select * from tbase order by id;
 id |   nickname    
----+---------------
  1 | hello TBase
  2 | TBase好
  3 | TBase好
  4 | TBase default
(4 rows)