Asynchronous file upload to an APEX_COLLECTION
If you are using asynchronous requests to upload data into an APEX_COLLECTION, you will end up with an ORA-00001: unique constraint violated (APEX_040100.WWV_FLOW_COLLECTION_MEMBERS_PK) . The reason is simple, sometimes APEX tries to insert the same value (WWV_FLOW_COLLECTION_MEMBERS$.SEQ_ID). A workaround consist of managing queues on the server side.