6 Replies Latest reply on Oct 5, 2012 1:29 PM by AnkitV

    Removing several columns from a huge table !!

      Hi All

      I need to remove around 20 columns from a table (5 GB in size). But before this, I need to take some backup.

      I know that taking export of this table is one option, but I will be followed a different way as I don't want to backup 600 columns for sake of 20 columns.

      I created a backup table by selecting only those 20 cols from the source table along with ROWID of source table in col ROWID_S. Size of this backup table came out to be 130 MB.

      My question is, will this backup prove to be correct in case I need to restore data from this into source table's columns on the basis of ROWID_S ?
      I mean will the join between ROWID_S and ROWID of source table be valid ?
      I am just thinking is there a possibility that ROWID of source table rows get changed somehow ?