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Sam_Jain's avatar
Sam_Jain
Icon for Helper III rankHelper III
2 years ago
Solved

Power BI Dataflow - response too large to return

Hello Community,   I have run into a PowerBI dataflow issue. My source table is in Big Query and is a table that gets updated daily and has data for the last 90 days in a rolling fashion.   What ...
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parry2k's avatar
parry2k
Icon for Super User rankSuper User
2 years ago

Sam_Jain Sorry very hard to tell what is going on. What error message do you get in gen2? I'm wondering if it is a transient error or if it is failing at the BQ end.

lbendlin's avatar
lbendlin
Icon for Super User rankSuper User
2 years ago
Can't use direct connection to BQ for access reasons

Challenge that assumption.  Tell them that 650 GB is too much.

 

If they don't budge, use Incremental Refresh. Start VERY small, with a day or so.  See how many rows you get.  Recommended partition size is around 8 to 20 million rows.

  • Sam_Jain's avatar
    Sam_Jain
    Icon for Helper III rankHelper III
    2 years ago

    Yea, so the 650 GB is for the entire dataset on BQ, which is roughly about a year's worth of data and the proposed solution is to have two datasets one rolled up monthly, which i was able to succesfully create and provide a dataflow access. The second one was a 90 day rolling window but at daily level and i was able to create a stored procedure on BQ that deletes the oldest day's data and add's new day's data from source table , had that schduled as a daily run to comply the 90 day rolling window.

    Challenge started when i created a dataflow off of it where the data size on bq is about 200 GB, which kept failing on me so i cut the columns into half to 30 from 50 odd. Still didn't work.

    So, i then filtered by date on power query editor - that worked! But now it only has 30 days of data and am not sure how i proceed from here?

    Also the dataset on BQ is partitioned by day for effeciency.

    From what you are suggesting, it looks like i have done the first bit getting data for 30 days and now i should use incremental refresh for every 15-30 days until i have all 90? Is that the right approach?
    Thanks.

     

    • lbendlin's avatar
      lbendlin
      Icon for Super User rankSuper User
      2 years ago

      Use the biggest partition size you can get away with.  Your choices are Day,Month,Quarter and Year.

       

      I would start with Day and check how many rows you get per partition. If not too many you can switch to Month.

      • Sam_Jain's avatar
        Sam_Jain
        Icon for Helper III rankHelper III
        2 years ago

        Please help me understand this step. My aim was to get data for the past 90 days - so period being = 9 April to 9 July or so. The current dataflow has data for last 30 days meaning - 9 June to 9 july. 
        What am i supposed to be inputting on the incremental refresh because the refresh rows days can't be higher than the store rows days.

         

        And if i am successful to even bring all the past 90 days somwhow, i still have to figure out a way to keep that as a rolling 90 day.

         

        Thanks and i appreciate all your help.