I thought of sharing this additional step I had to do while using jBPM5.2 with Oracle.
I had to run the following SQL to create the sequences as there were not generated using JBPM5.2.
CREATE
SEQUENCE SESSIONINFO_ID_SEQ START WITH 1 INCREMENT BY
1 NOCYCLE;
CREATE
SEQUENCE WORKITEMINFO_ID_SEQ START WITH 1 INCREMENT BY
1 NOCYCLE;