如何检查Undo表空间使用情况

小编给大家分享一下如何检查Undo表空间使用情况，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！
######脚本###########
SELECT TABLESPACE_NAME, ROUND ( (USED / TOTA免费主机域名L_SIZE) * 100, 2) USED_RATE
FROM (SELECT A.TABLESPACE_NAME, TOTAL_SIZE, USED
FROM ( SELECT TABLESPACE_NAME,
ROUND (SUM (BYTES) / 1024 / 1024 / 1024, 2) TOTAL_SIZE
FROM DBA_DATA_FILES
WHERE 1 = 1 AND TABLESPACE_NAME LIKE ‘UNDOTBS%’
GROUP BY TABLESPACE_NAME) A,
( SELECT TABLESPACE_NAME,
ROUND (SUM (BYTES) / 1024 / 1024 / 1024, 2) USED
FROM DBA_UNDO_EXTENTS
WHERE 1 = 1 AND STATUS = ‘UNEXPIRED’
GROUP BY TABLESPACE_NAME) B
WHERE 1 = 1 AND A.TABLESPACE_NAME = B.TABLESPACE_NAME);
——————————————————————————————————————
The Expired blocks will be reused and hence this should be counted as ‘available’ space in the Undo segment.

You can check the status of the undo extents via the SQLs below.
select sum(bytes /(1024*1024)) from dba_undo_extents where status=’EXPIRED’;
select sum(bytes /(1024*1024)) from dba_undo_extents where status=’ACTIVE’;
select sum(bytes /(1024*1024)) from dba_undo_extents where status=’UNEXPIR免费主机域名ED’;

For more detailed information, please refer to：
Master Note: High Undo Space Usage ( Doc ID 1578639.1 )

Above all, if the undo status is Expired, you can safely ignore the undo usage, as the space will be reused automatically.以上是“如何检查Undo表空间使用情况”这篇文章的所有内容，感谢各位的阅读！相信大家都有了一定的了解，希望分享的内容对大家有所帮助，如果还想学习更多知识，欢迎关注云技术行业资讯频道！

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