具有时间有效性的Oracle表的主键冲突

Question

你能给我一些关于表的主键操作在Oracle中具有时间有效性的一些看法吗？

我创建了一个具有以下架构的表

Create table TemporalTable_1 (
    Customer_ID number(8),
    Customer_name varchar2(100),
    valid_period_start timestamp, 
    valid_period_end timestamp, 
    period for valid_period(valid_period_start, valid_period_end),
    constraint TemporalTable_1_PK primary key (Customer_ID , VALID_PERIOD)
)

 
Customer_ID       | Customer_name        | Valid_period_start      | Valid_Period_end
------------------+----------------------+-------------------------+-----------------------
00001             | John Chan            | 01 JUN 2020 00:00:00    | 09 JUN 2020 23:59:59
00001             | Johnny Chan          | 10 JUN 2020 00:00:00    | Null

insert into TemporalTable_1 select * from OtherTable;

是因为Oracle实际上并不关心主键上的有效期列吗？

提前道谢！

Answer 1

Period name(VALID_PERIOD在您的例子中是）列只包含您的Period的ID。检查此脚本及其输出：

--drop table TemporalTable purge;
-- formatting for sqlplus:
col periodname for a20;
col constraint_name for a20;
col search_condition_vc for a80;
col valid_period_start for a16;
col valid_period_end   for a16;
col PERIODSTART for a20;
col PERIODEND   for a20;
alter session set nls_timestamp_format='yyyy-mm-dd hh24:mi';
-- end of formatting

Create table TemporalTable (
    Customer_ID number(8),
    Customer_name varchar2(10)
);

alter table TemporalTable add (
    valid_period_start timestamp, 
    valid_period_end   timestamp,
    period for valid_period(valid_period_start, valid_period_end)
);

ALTER TABLE TemporalTable ADD (
    vt_start DATE,
    vt_end DATE,
    PERIOD FOR vt (vt_start, vt_end)
);
-- inserting overlapping records:
insert into TemporalTable
select 1, 'A' , date'2020-01-01', date'2020-01-10', date'2020-01-01', date'2020-01-10' from dual union all
select 1, 'B' , date'2020-01-05', date'2020-01-08', date'2020-01-01', date'2020-01-10' from dual
/
commit;
-- check valid_period and vt hidden columns:
select tt.*,valid_period,vt from TemporalTable tt
/
select * 
from TemporalTable 
       AS OF PERIOD FOR valid_period DATE '2020-01-06'
/
select 
 constraint_name,
 constraint_type,
 search_condition_vc
from user_constraints c 
where table_name='TEMPORALTABLE';

select * from sys.SYS_FBA_PERIOD 
where obj#=(select object_id from user_objects where object_name='TEMPORALTABLE');