openGauss每日一练第16天 |学习openGauss事务控制

一、课程作业

1.以默认方式启动事务1，修改事务隔离级别，查看transaction_isolation

START TRANSACTION;
select * from pg_class limit 1;
SET LOCAL TRANSACTION ISOLATION LEVEL READ COMMITTED READ ONLY;
show transaction_isolation;
end；

2.以读写方式启动事务2，创建新表，修改事务为只读事务，查看transaction_read_only，并向表中插入记录

START TRANSACTION ISOLATION LEVEL repeatable read READ WRITE;
show transaction_isolation;
SET LOCAL TRANSACTION ISOLATION LEVEL repeatable read READ ONLY;
show transaction_isolation;
insert into  charley values(1);
end;

3.启动事务3，对表进行增删改查，并用到创建savepoint，回滚savepoint和删除savepoint

START TRANSACTION;
create table charley(id int);
insert into  charley values(1);
insert into  charley values(2);
SAVEPOINT my_savepoint;
delete from  charley where id=2;
ROLLBACK TO SAVEPOINT my_savepoint;
insert into  charley values(3);RELEASE SAVEPOINT my_savepoint;
insert into  charley values(4);
commit;select * from charley;

4.清理数据

drop table charley;

二、学习心得

每天学习一点点、进步一点点。