建异步物化视图，报这个错，是哪里没写错对么？

CREATE MATERIALIZED VIEW mv1 
        BUILD DEFERRED REFRESH AUTO ON MANUAL
        partition by(cur_dt)
        DISTRIBUTED BY RANDOM BUCKETS 19
        PROPERTIES (
    "replication_num" = "1",
    "dynamic_partition.enable" = "true",
    "dynamic_partition.time_unit" = "MONTH",
    "dynamic_partition.start" = "-48",
    "dynamic_partition.end" = "1",
    "dynamic_partition.prefix" = "m",
    "dynamic_partition.buckets" = "19"
        ) 
        AS 
        select date_trunc(cur_dt, 'month') as year_month, hour(cur_time) as hour
, user_id, device_code, big_type, alert_type,  sum(alert_count) as alert_count 
from test.flink_to_doris_prod
group by  year_month, hour, user_id, device_code, big_type, alert_type
;