2 Replies Latest reply: May 31, 2009 5:24 PM by Oleg Troyansky RSS

    Incremental reload




      I don't have the modified and time in my database. Then I tried using the max( sequence no /Transaction no).This option also I cant use because there are multiple sequences.

      For Example, they are having different sequence for Tax invoice (TINV00001) and Non Tax invoices (NTINV00003).If I take max(),I'll get any one sequence only.


      Is there any other way to do the incremental load?


      Thanks in advance..





        • Incremental reload
          Michael Solomovich

          There should be some record identifier one way or another...
          If really there are none, you can use rule:
          max(Tax number) OR max(nonTax number)
          Certainly there will be overlap, but you can deal with it later using DISTINCT or EXISTS.

            • Incremental reload
              Oleg Troyansky

              It's practically impossible to develop a RELIABLE incremental load algorithm without a timestamp or another unique ID... There are techniques of dealing with it on the host database, but those techniques are very intrusive. For example, you (or those developers responsible for the back end database) could develop a set of triggers that would store every new/modified/deleted records in separate tables, giving you the "net change". This is typically more complex than it is beneficial... Ask yourself if you REALLY need the incremental load or if it's just a "nice to do"...