Incremental Dataflow on Oracle ADW ORA-01013: user requested cancel of current operation

We had the same issue with Power BI and the Oracle incremental refreshes failing while full refreshes took a long time but completed successfully.  Same error message as posted by OP.  What fixed the problem for us is increasing the Fetch Size in the registry entry on the data gateway server.  Most likely ORA-01013 is an erroneous message from Oracle which doesn't really mean the user cancelled but most likely the query timed out.  The fix is to improve the performance of the Oracle query and the default fetch size set in ODAC 19.x driver. 

https://www.oracle.com/a/ocom/docs/database/microsoft-powerbi-connection-adw.pdf

Update ODAC driver Fetch Size settings in registry:
Unmanaged ODP.NET Instructions To increase the 32-bit or 64-bit unmanaged ODP.NET’s FetchSize, launch the Windows Registry editor (regedit.exe) and go to the following Registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Oracle\ODP.NET\4.122.19.1 Add the String Value "FetchSize" and set it to a value larger than the default (131072), such as 4194304 (4 MB).