6 Replies Latest reply on Feb 3, 2020 8:55 AM by user101600

    CDC Cold Start

    sagar sawant Active Member

      hi,

       

      How cold start =y and N behaves in CDC ?

      Also Does previous log gets added to overall session level when we do coldstart='N'

      eg

      In first run data count = 40 rows

      and then my cdc service stopped working due to some x reason or downtime taken .

      After doing coldstart='N'

      suppose 12 new rows came.

      and then what will it show in overall monitor level log ? (task view )  Log shows me exact time of condense file from the time where it got shut down just curious about overall rows count shown in monitor)

      target count= 52 rows or 12 rows ??

        • 1. Re: CDC Cold Start
          dan.smith@informatica.com Guru

          Row counts should not be cumulative across sessions.

          Each one is distinct, even with a warmstart.

          1 of 1 people found this helpful
          • 2. Re: CDC Cold Start
            sagar sawant Active Member

            Im getting it cumulative so what should i do ?

            and in my database if i write query for row count greater than the timestamp at which my cdc stopped working im getting 1lakhs only.

             

            *( In above screenshot i have started cdc session around 5pm and its showing total rows count 18lakhs but same if i write query for row count greater than the 5pm at which my cdc started working im getting 1lakhs rows only)*

            • 3. Re: CDC Cold Start
              dan.smith@informatica.com Guru

              I really don't know.

              That's all in PowerCenter code, not PWX code.

               

              I would suggest raising a PowerCenter support case, and asking how those fields are calculated, and why you are seeing the results that you're seeing.

              • 4. Re: CDC Cold Start
                sagar sawant Active Member

                Do we get data count in PWX code ?

                • 5. Re: CDC Cold Start
                  dan.smith@informatica.com Guru

                  No.

                  1 of 1 people found this helpful
                  • 6. Re: CDC Cold Start
                    user101600 Guru

                    I am not sure what your CDC Source is,
                    but assuming that its MF CDC source.

                    The coldstart parameter works this way.

                    • N. The ECCR warm starts. Change capture starts from where it last left off without loss of data.
                    • Y. The ECCR cold starts. Change capture starts from the oldest record in the CDC tables.

                     

                    Assuming that the source is an oracle CDC source
                    Then The coldstart parameter works this way.

                    • A cold start uses the restart and sequence tokens, if present, in the pwxccl configuration file to determine the point in the change stream from which the PowerExchange Logger starts reading changes. If you are starting the PowerExchange Logger for the first time, you must perform a cold start. When you enter the pwxccl command to start the PowerExchange Logger, set the coldstart parameter to Y.
                    • A warm start uses the restart and sequence tokens in the CDCT file to resume CDC processing. You can perform a warm start only if you have run the PowerExchange Logger previously and have a recent CDCT file for the database instance. When you enter the pwxccl command for starting the PowerExchange Logger, set the coldstart parameter to N or omit the parameter.
                    • A special start uses the restart and sequence tokens in the pwxccl.cfg file to override the token values from the CDCT file for the PowerExchange Logger run. None of the data that was captured prior to the special start is lost. You must enter the SEQUENCE_TOKEN and RESTART_TOKEN parameters in the pwxccl.cfg. The SEQUENCE_TOKEN value must be greater than or equal to the sequence token in the CDCT file.

                     

                    All of this infromation is fully documented in the manual.

                    Please take a look a the following link for more info.

                    COLDSTART Parameter