2 Replies Latest reply on Aug 19, 2019 4:31 PM by Vikas Panwar

    multiple extracts writing to single trail file

    lan_baba

      Hi everyone, newbie here. I have a not so make sense question here, since I know usually ppl will ask the question other way around. Anyway, here is the question:

      Can I have multiple extracts writing to a single trail file, and one single replicat reading it? Will it cause any issues, besides it will make the replicat extra busy, maybe even lagging?

        • 1. Re: multiple extracts writing to single trail file
          ORASCN

          Hi Lan,

           

          This is not possible. Because, each process has and maintain it's own checkpoint file. The extract process once restarted will read this checkpoint file and will come to know where to start writing again and read position.

           

          Multiple Extract cannot write to a single trail file because, it leads to trail file corruption.

           

          But, multiple replicat process can read from single trail file.

           

          Regards,

          Veera

          • 2. Re: multiple extracts writing to single trail file
            Vikas Panwar

            Hi @Lan_baba,

             

            Multiple extract --> writing in one trail   -- this is not possible
            multiple replicat --> reading one same trail -- that is possible

             

            If you have multiple schemas on same database. You can try writing extract which deals with all required tables coming from these schemas.

            for example

             

            extract ext1

            ..

            schema1.t1

            schema2.t2

            schema1.t1

            ....

             

            This way while extracting itself you will extract data from differenct schemas (if that is your requriement)

             

            Then once this data is written into trail -- your replicat can read that.

             

            Just to give you an idea what kind of error comes when you have multiple extracts writing to same trail

            ext1   writing at rba  111

            ext2   writing at rba   222 or may be it also want to write at 111

            and so on

            on your trail side GG will not understand what is coming from where.

             

            Hope this helps

            mark it correct, helpful or like it appropriately. This will help others also

             

            -VP