摘要： (Multi-Version Concurrency Control多版本并发控制）介绍Maintain data consistency internally • While querying a database each transaction sees a snapshot of data (a database version) as it was some time ago • Prevent transaction from viewing inconsistent data • Provides transaction isolation in concurrent tr... 阅读全文

摘要： 6 sequence序列highgo=# create sequence t_seq increment by 1 start with 1;CREATE SEQUENCEhighgo=# select nextval('t_seq'); 查看序列中下一个值nextval--------- 1(1 行记录)highgo=#create table t(id int default nextval(‘t_seq’),name varchar); 在定义时使用sequenceCREATE TABLEhighgo=# insert into t(name) values('j 阅读全文