ALTER SYSTEM { archive_log_clause | CHECKPOINT [ GLOBAL | LOCAL ] | CHECK DATAFILES [ GLOBAL | LOCAL ] | { ENABLE | DISABLE } DISTRIBUTED RECOVERY | { ENABLE | DISABLE } RESTRICTED SESSION | FLUSH SHARED_POOL | end_session_clauses | SWITCH LOGFILE | { SUSPEND | RESUME } | { QUIESCE RESTRICTED | UNQUIESCE } | SHUTDOWN [IMMEDIATE] dispatcher_name | REGISTER | SET alter_system_set_clause [, alter_system_set_clause]... | RESET alter_system_reset_clause [, alter_system_reset_clause]... } ;