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Anske's avatar
Anske
Frequent Visitor
6 years ago

Group by on Redshift Data Source Table causes great many active sessions (connection limit exceeded)

Hi,

 

I have a fairly simple report loading 10 tables from a single Redshift Datasource, I never had any troubles so far, until today when I duplicated one of the queries and performed a Group By step in the Edit Queries view.  Now it gives the following error 

DataSource.Error: ODBC: ERROR [53300] [Microsoft][Amazon Redshift] (10) Error occurred while trying to connect: [SQLState 53300] FATAL: connection limit "498" exceeded for non-superusers.

 

Being a superuser myself, I checked open connections for the power bi user in the stl_connection_log, and low and behold, there's over 400 open connections, starting at the time I added the group by to the stept, a couple of connections starting up per second for this special pbi user I've made (and yes, I'm completely sure no one else and no other reports are querying the datasource with this user), ranging over a couple minutes (so from 12:45:55 to 12:48:14). 

How do all these connections get created?? Are there any known issues creating this behaviour, or is it not a power bi issue at all? I'm in import mode, not in direct query mode, by the way. 

Thanks.

 

Need Help

3 Replies

  • Greg_Deckler's avatar
    Greg_Deckler
    Community Champion
    6 years ago

    I've seen certain operations in Power Query against certain data sources cause problems. You could check the Issues forum and see if it is mentioned and if there is a solution. https://aka.ms/PBI_Comm_Issues

     

    Also, you could use a work-a-round by using DAX SUMMARIZE or SUMMARIZECOLUMNS to create a new table in your data model.

    Anske 

  • v-juanli-msft's avatar
    v-juanli-msft
    Community Support
    6 years ago

    Hi Anske 

    If you use direct query, it is unsupported to transform data like "group by".

    Also, please check if you use any unsupported data types:

    https://docs.aws.amazon.com/redshift/latest/dg/c_Supported_data_types.html

     

    If error still occurs, please create a support ticket for further analysis.

    https://powerbi.microsoft.com/en-us/support/

     

    Best Regards
    Maggie
    Community Support Team _ Maggie Li
    If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

    • Anske's avatar
      Anske
      Frequent Visitor
      6 years ago

      Hi Maggie, 

       

      as I remarked in my initial question, I'm NOT using direct query.

       

      Cheers, 

      Anske.