表现为
select tuned_undoretention from v$undostat;
的值异常大，UNDO_DATAFILE 不断的自动扩张。
mos有相关的BUG说明
Bug 7291739 Contention with auto-tuned undo retention or high TUNED_UNDORETENTION
Product (Component)Oracle Server (Rdbms) Range of versions believed to be affectedVersions BELOW 11.2 Versions confirmed as being affected Platforms affectedGeneric (all / most platforms affected)
select tuned_undoretention from v$undostat;
的值异常大，UNDO_DATAFILE 不断的自动扩张。
mos有相关的BUG说明
Bug 7291739 Contention with auto-tuned undo retention or high TUNED_UNDORETENTION
Product (Component)Oracle Server (Rdbms) Range of versions believed to be affectedVersions BELOW 11.2 Versions confirmed as being affected Platforms affectedGeneric (all / most platforms affected)
Description
High 'latch: row cache objects' contention may be seen on dc_rollback_segments together with high 'enq: US - contention' waits when using system managed undo with an auto tuned undo retention period. As another aspect, long running query can raise tuned_undoretention to very high value and exhaust undo tablespace resulting in ORA-1628.Workaround Disable auto tuning by setting "_undo_autotune" = false记录于此备查
