刷新嵌套的物化视图时如何捕获错误

Question

物化视图“MV_AMP”：

CREATE MATERIALIZED VIEW MV_AMP
  NOLOGGING
  BUILD IMMEDIATE
  REFRESH FORCE
  ON DEMAND
AS
Select a, b, c from amp;

物化视图“MV_BOT”依赖于“MV_AMP”：

CREATE MATERIALIZED VIEW MV_BOT
  NOLOGGING
  BUILD IMMEDIATE
  REFRESH FORCE
  ON DEMAND
AS
SELECT bot.x, bot.y, mv_amp 
FROM bot, mv_amp
WHERE bot.a = mv_amp.a;

并在mv_bot中创建一个唯一索引：

CREATE UNIQUE INDEX mv_bot_idx001 ON mv_bot(x, a);

在视图和索引创建成功后，假设我在刷新mv_bot时由于唯一索引而添加了导致类似（dup_val_on_index）的错误的重复值。

所以我使用嵌套= TRUE在MV_AMP（主视图）中刷新，并且Oracle没有引发错误：

BEGIN
  dbms_mview.refresh_dependent(number_of_failures => n_failures,
                                   list => 'MV_AMP',
                                   atomic_refresh => TRUE,
                                   nested => TRUE);

EXCEPTION
  WHEN
    OTHERS THEN
        -- it never reach this code
        dbms_output.put_line('Errors: '||SQLERRM);
END;

n_failures返回：0并且它永远不会到达异常中的dbms_output。

当oracle尝试更新嵌套的MV并登录表时，我需要捕获错误。

使用Oracle 11g。

Answer 1

只有在物化视图EXCEPTION中有重复的行时才会到达MV_BOT块 - 事实并非如此。

你可能会问为什么;最有利的答案是你需要刷新物化视图MV_AMP以获得MV_BOT连接中的dup。

在阅读dbms_mview.refresh_dependent的文档时，你会发现，你必须从表AMP开始，以获得两个MV的刷新（从MV_AMP开始仅刷新依赖的MV MV_BOT）

测试用例

create table amp (
a number,
b number,
c number);

create table bot (
a number,
x number,
y number);

CREATE MATERIALIZED VIEW MV_AMP
  NOLOGGING
  BUILD IMMEDIATE
  REFRESH FORCE
  ON DEMAND
AS
Select a, b, c from amp;

CREATE MATERIALIZED VIEW MV_BOT
  NOLOGGING
  BUILD IMMEDIATE
  REFRESH FORCE
  ON DEMAND
AS
SELECT bot.x, bot.y, mv_amp.a 
FROM bot, mv_amp
WHERE bot.a = mv_amp.a;

CREATE UNIQUE INDEX mv_bot_idx001 ON mv_bot(x, a);

insert into amp(a,b,c) values(1,1,1);
insert into bot(a,x,y) values(1,1,1);
insert into bot(a,x,y) values(1,1,3);
commit;

DECLARE
  n_failures NUMBER;
BEGIN
  dbms_mview.refresh_dependent(number_of_failures => n_failures,
                                   list => 'AMP',
                                   atomic_refresh => TRUE,
                                   nested => TRUE);
   dbms_output.put_line('Failures: '||n_failures);                                                                
EXCEPTION
  WHEN
    OTHERS THEN
        dbms_output.put_line('Errors: '||SQLERRM);
END;
/

--> Errors: ORA-12008: error in materialized view refresh path
--> ORA-00001: unique constraint (xxxxx.MV_BOT_IDX001) violated