Oracle Internals
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Dumps

Undo for a Transaction

To dump all the undo written for a specific transaction, first identify the transaction ID using

    SELECT xidusn, xidslot, xidsqn
    FROM v$transaction;

Dump the undo using the transaction ID

    ALTER SYSTEM DUMP UNDO BLOCK 'segment_name'
    XID xidusn xidslot xidsqn;