SanthuTeradata

 Profile Answers by SanthuTeradata 

• Mar 29th, 2011

 

We use both before journal and after journal in Permenent journal to do selective or full recovery of data..........

consider Today Monday**

Yesterday--------->Before Image
Tuesday------------>After Image
Wednesday-------->After Image
    |           |
    |           |
Saturday------------>After Image

Full recovery data=Before image+(Tues - Mon)After Image
Selective Rexovery=Before Image+(Tues-Friday)After Image


Here  Before Image = Before Modification occured

          After Image   =After Modifcation Occured

yuvaevergreen

 Profile Answers by yuvaevergreen 

• Jun 7th, 2011

 

Before Journal keeps the images of the table before making the change to the table. Very useful, if the changes need to be reverted incase of a fault or rollback. 

After Journal keeps the images of the table after the changes has been made to the table.