The possible causes for Excessive Undo generation

1)Transactions with huge undo. ——————————- It is obvious to see high undo usage when there are huge transactions. If that is going to be the case this growth should be expected behavior. 2)The Higher value setting of UNDO_RETENTION. ———————————————— The higher value of UNDO_RETENTION will increase much undo. As it can’t be marked undo extents [...]

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The possible causes for Excessive Undo generation

1)Transactions with huge undo. ——————————- It is obvious to see high undo usage when there are huge transactions. If that is going to be the case this growth should be expected behavior. 2)The Higher value setting of UNDO_RETENTION. ———————————————— The higher value of UNDO_RETENTION will increase much undo. As it can’t be marked undo extents [...]

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Optimizing Undo

Calculate UNDO_RETENTION for given UNDO Tablespace You can choose to allocate a specific size for the UNDO tablespace and then set the UNDO_RETENTION parameter to an optimal value according to the UNDO size and the database activity. If your disk space is limited and you do not want to allocate more space than necessary to [...]

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