 A redo record, also called a redo entry, holds a group of change vectors, each of which describes or represents a change made to a single block in the database.For example, if a user codice_1s a salary-value in a table containing employee-related data, the DBMS generates a redo record containing change-vectors that describe changes to the data segment block for the table.And if the user then codice_2s the update, Oracle generates another redo record and assigns the change a "system change number" (SCN).