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Iaguas's avatar
Iaguas
Frequent Visitor
1 year ago
Solved

Error refreshing on desktop and service

My report stopped refreshing on desktop and service, displaying the following errors respectively: "Failed to save modifications to the server. Error returned: 'OLE DB or ODBC error: [DataSource.Err...
Need Help
  • NimaiAhluwalia's avatar
    NimaiAhluwalia
    1 year ago

    Hello Iaguas 

    A list of possible solutions for you to try!!

     

    • Confirm the PostgreSQL server is online and accessible.

    • Verify credentials and permissions haven’t changed.

    • Test the connection in Power BI Desktop → Data source settings → Test Connection.

    • Ensure VPN, SSL, or firewall isn’t blocking Power BI.

    • Large tables or queries returning huge datasets can cause streaming issues.

    • Try filtering the data (e.g., limit rows to 1000) and see if it refreshes.

    • Consider query folding or pre-aggregating data in the database before loading.

    • Ensure the PostgreSQL ODBC/Npgsql driver is up-to-date on your machine.

    • Power BI recommends using the latest Npgsql driver for PostgreSQL.

    • Mismatched or old drivers can cause stream read errors.

    • Increase the data load timeout in Options → Data Load → Timeouts.

    • Temporarily disable background data to see if refresh succeeds.

    • If using an on-premises gateway, check that the gateway version is latest.

    • Ensure the gateway can connect to the PostgreSQL server.

    • Check network stability interruptions can cause stream exceptions.

    • Complex transformations in Power Query can break query folding.

    • Review applied steps in Power Query and try simplifying transformations.

    • Test if simpler queries refresh successfully.

    • Enable diagnostic tracing in Power BI Desktop: File → Options → Diagnostics → Enable tracing.

    • Split large tables into smaller chunks.

    • Use incremental refresh instead of full refresh.

    • Consider using DirectQuery mode instead of Import, if feasible

     

Poojara_D12's avatar
Poojara_D12
Icon for Super User rankSuper User
1 year ago

Hi Iaguas 

The error you are seeing, “PostgreSQL: Exception while reading from stream”, usually points to an issue with the connection between Power BI and your PostgreSQL database, rather than with your report itself. This happens when the query engine starts receiving data from PostgreSQL but the connection is interrupted before completion. Common causes include network instability, timeouts due to long-running or heavy queries, resource limits being hit on the PostgreSQL server, or a mismatch in drivers. In Power BI Desktop, it often fails if the query is pulling back very large datasets without proper filtering, while in the Service it can also be affected by gateway configuration or idle connection timeouts. To fix it, you should check whether queries are optimized and returning only the necessary data, make sure the Npgsql/PostgreSQL ODBC driver is updated on both Desktop and the gateway machine, and confirm that the database server is not dropping long sessions due to memory, CPU, or timeout settings. If it works intermittently, it’s very likely network or gateway related; if it always fails at the same stage, it’s more likely a query or resource issue on the PostgreSQL side.