materialized view 和snapshot

在新系统下，曾经用“快照”的情况，现在就用“物化视图”好了。

 

1. 描述:

　　MV 跟 Snapshot 的功能类似 , SQL Navigator down 出来也是 snapshot , 但是底层还是有不一样的地方 . 请搞清楚是 MV 还是 Snapshot

2. 结论:

(1) Snapshot 与 MV 是同义词. 创建完毕导出的dll文件说明是snapshot.

(2) MV log　是与　Refresh 的方式有关. Fast 方式才需要 LOG.

(3) MV 是新名词, snapshot 是旧名词而已. 仅仅为了保持兼容性

The keyword SNAPSHOT is supported in place of MATERIALIZED VIEW for backward compatibility.

 

创建 snapshot create snapshot SNAP_TEST as select * from test11;

drop snapshot SNAP_TEST; 

 

创建mv create materialized view

GENERIC_CLA_DENORM 

build immediate

using index

refresh complete on demand

AS

select * from test11;

analyze table generic_cla_denorm compute statistics ; 

 

两种刷新方式 

exec dbms_mview.refresh('SNAP_TEST');

BEGIN

  DBMS_SNAPSHOT.REFRESH(

    LIST                 => 'SNAP_TEST'

   ,PUSH_DEFERRED_RPC    => TRUE

   ,REFRESH_AFTER_ERRORS => FALSE

   ,PURGE_OPTION         => 1

   ,PARALLELISM          => 0

   ,ATOMIC_REFRESH       => TRUE

   ,NESTED               => FALSE);

END;