TAF can be verified by querying the Oracle-provided views

Implementation of TAF can be verified by querying the Oracle-provided data dictionary views. V$SESSION has three columns, FAILOVER_MODE, FAILOVER_TYPE, and FAILED_OVER, that provide information pertaining to TAF implementation, and verification of results when the node in the cluster crashes and the session fails over to one of the available nodes.

SELECT SID, USERNAME, FAILOVER_TYPE, FAILOVER_METHOD, FAILED_OVER
FROM V$SESSION
/
SID USERNAME FAILOVER_TYPE FAILOVER_M FAILED_OVER
———- ———————- ————- ———- ———–
316 OLTP_USER SELECT BASIC YES
317 OLTP_USER SELECT BASIC NO
320 OLTP_USER SELECT BASIC NO
326 OLTP_USER SELECT BASIC NO
1257 SRV10 NONE NONE NO
328 OLTP_USER SELECT BASIC YES