Hi Pawel,
Thanks for the suggestions. For those who are struggling with the issue, we added the following properties to our datasource paramters (further to Pawel's response ):
<entry key="db2.jcc.override.fullyMaterializeLobData" value="true" />
<entry key="db2.jcc.override.fullyMaterializeInputStreams" value="true" />
<entry key="db2.jcc.override.progressiveStreaming" value="2" />
<entry key="db2.jcc.override.progresssiveLocators" value="2" />
Hope it helps.
Thanks.