ORA-01555 snapshot too old: rollback segment number string with name "string" too smallCause: Rollback records needed by a reader for consistent read are overwritten by other writers.Action: If in Automatic Undo Management mode, increase the setting of UNDO_RETENTION. Otherwise, use larger rollback segments.
ORA-01555 snapshot too old: rollback segment number string with name "string" too smallCause: Rollback records needed by a reader for consistent read are overwritten by other writers.Action: If in Automatic Undo Management mode, increase the setting of UNDO_RETENTION. Otherwise, use larger rollback segments.
1、优化SQL,如不能优化,就把大查询分为小块分别进行。
2、加大回滚段或撤销段
3、用撤销段时增大UNDO_RETENTION参数值,该值为过期数据在撤销段中保留时间。
4、10g的话,配合第三点可在撤销表空间上启用撤销保留保证retention guarantee特性。
2.增加undo空间和undo_retention。 只要足够大都能解决.
3.把大业务的commit分成多个子commit。
如果实在没别的方法,你就配合retention guarantee来用。
我以前也是这样做的,分成小块一部分一部分的运行。