ORA-26536

Error: ORA-26536: refresh was aborted because of conflicts caused by deferred transactions

Causa: There are outstanding conflicts logged in the DEFERROR table at the materialized view's master site.

Acción: Resolve the conflicts in the master DEFERROR table and refresh again after the table is empty. Alternatively, refresh with REFRESH_AFTER_ERRORS, even if there are conflicts in the master's DEFERROR table. Proceeding despite conflicts can result in an updatable materialized view's changes appearing to be temporarily lost, until a refresh succeeds after the conflicts are resolved.