Oracle Error Message
QSM-01279: query rewrite not possible because DML operation occurred on a table referenced by materialized view string
Reason for the Error
If any dependent tables of a materialized view undergoes a DML operation, query rewrite may be restricted depending on the query rewrite integrity mode for the session. In this situation, query rewrite will take place only if the rewrite integrity mode is STALE_TOLERATED.
Solution
Consider refreshing the materialized view changing the rewrite integrity mode to STALE_TOLERATED.