Different Oracle client OLE DB versions and performance

[qliktime]

I'm evaluating to upgrade from oracle12 drivers for OLEDB to either oracle19 or oracle21.

The setup I'm running for QlikSense is pretty much identical to what is described her
How to set up an Oracle OLE DB connection in Qlik ... - Qlik Community - 1549395

I have a test table in an Oracle database, with 8 million rows. The DB is for test purposes and it is not heavily used.

Version	Time (about three tries each)
oracle12	50 seconds (+/- 5 seconds)
oracle19	more than 15 minutes (aborted)
oracle21	1 min 10 seconds (+/- 5 seconds)

Have anyone experienced something similiar?

Any solutions?

For reference: the QlikSense servers are running virtual Windows Server 2019, 24 gb RAM, 4 cpus at 2,2 GHz , (Xeon E5-2699)