In an Oracle database, a change vector consists of a single change to a single data block. A change vector is the smallest unit of change recorded in a

redo log Undo is an interaction technique which is implemented in many computer programs. It erases the last change done to the document, reverting it to an older state. In some more advanced programs, such as graphic processing, undo will negate the las ...

(in its turn, a redo log comprises files in a proprietary format which logs a history of all changes made to the database).

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Change Vector
Oracle software Transaction processing {{Compu-stub