DBA_MVIEWS的LAST_REFRESH_DATE字段或者DBA_MVIEW_REFRESH_TIMES的LAST_REFRESH字段记录了Oracle物化视图刷新的起始时间。但如果我们想查看物化视图的刷新到底花费了多长时间，应该怎么做呢。其实，我们可以查询DBA_MVIEW_ANALYSIS。

对于完全刷新（Complete）,刷新耗时会记录在DBA_MVIEW_ANALYSIS的FULLREFRESHTIM列中。而对于可快速刷新（Fast）的时间，会记录在INCREFRESHTIM列中。
这两个值的单位都是秒。

SELECT mview_name, last_refresh_date, fullrefreshtim, increfreshtim
FROM dba_mview_analysis
WHERE owner='JOHN';

MVIEW_NAME               LAST_REFRESH_DATE      FULLREFRESHTIM INCREFRESHTIM
------------------------ ---------------------- -------------- -------------
MV_CHANGE_HISTORY        07-JAN-13 04.36.58 PM               0            36
MV_ITEM_HISTORY          07-JAN-13 04.36.58 PM               0             9

上例表明MV_CHANGE_HISTORY与MV_ITEM_HISTORY最近的刷新为快速刷新，分别耗时36秒和9秒。

把它们放在一个查询里计算和显示终止时间。

SELECT 
   mview_name,
   last_refresh_date "START_TIME",
   CASE
      WHEN fullrefreshtim <> 0 THEN
         LAST_REFRESH_DATE + fullrefreshtim/60/60/24
      WHEN increfreshtim <> 0 THEN
         LAST_REFRESH_DATE + increfreshtim/60/60/24
      ELSE
         LAST_REFRESH_DATE
   END "END_TIME",
   fullrefreshtim,
   increfreshtim
FROM all_mview_analysis
WHERE owner='JOHN';

MVIEW_NAME          START_TIME             END_TIME               FULLREFRESHTIM INCREFRESHTIM
------------------- ---------------------- ---------------------- -------------- -------------
MV_CHANGE_HISTORY   07-JAN-13 04.36.58 PM  07-JAN-13 04.37.34 PM               0            36
MV_ITEM_HISTORY     07-JAN-13 04.36.58 PM  07-JAN-13 04.37.07 PM               0             9

Reference: How To Calculate MVIEW Refresh Duration? What Does DBA_MVIEWS.LAST_REFRESH_DATE and DBA_MVIEW_REFRESH_TIMES.LAST_REFRESH Indicate? [ID 1513554.1]

原文链接：http://oraexplorer.com/2013/01/how-long-did-oracle-materialized-view-refresh-run/

本文链接：http://bookshadow.com/weblog/2014/11/02/how-long-did-oracle-materialized-view-refresh-run/
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