I have observed for one of my customers that PDCR job took more time for approximately same amount of data to copy. For ex-
PDCR DBQL job took 17 Mins and 22 Secs to Copy 8.19 M records which is approximately close to yesterday’s 8.09 M records which took only 8mins and 28 secs.
i am not sure why it took almost double the time to copy same amount of data, where i have observed that there was no blocking or any performace issues, neither we have made any changes.
is it related to the kind of data that it is copying? is is there anything else which i am missing?
Your observed difference is in elapsed time and there are a number of things that can affect that (you've already discounted blocking which is one of them). How about:
If you've got DBQL for both sets of queries, look at AMPCpuTime, TotalIOCount and the 'physical IO' columns. These will tell you if the two sets of queries are doing the same amount of work.
Thanks for the respose and suggestion, yes i have compared the result and can see more ampcputime,totaliocount and physicalio count for the it ran more time. but i dont think this has made any difference, can you tell me if this makes any sense,please see the results below .
PRE-PROD PDCR JOB
PS- The query took almost double time on 19th
Assuming that 19/10 is the 'long run'... that is using @2.5 times the amount of CPU compared to the previous day.