1. If sql query is travelling through network then it may be the case that too many frames get droped at times resulting in disconnect.
Try running the script and execute a ping <oracle server domain / IP> -t and redirect it too some text file and if your script fails then check the ping log file.
2. If your statement involves too many joins or group by ( sql statement ) then may be oracle rejects it at times.
In this case break it using where clause or having keyword.
but I saw it happened with me, i open another ODBC and deleted this one after 5 min then click on Select button and qlikview ask for the obbc connection. However my Oracle ODBC was on its place and i have not saved the script after opening or deleting second odbc.
Logically they are not possible but in real scenario they happens.
In your case it seems like network reset issue, that means network got reset between resulting qlikview throw error.
Is your Issue resolved kindly reply.
i am also facing the same issue where i am connected to Oracle database but it doesn't fetch any records, just remain as it is " Displaying Connected in the Script after the Connection String", whereas in the Existing Environment its working fine. We are in the Migration Project.
Thanks in advance.