物化视图与允许过滤的查询

我有下表 users((username), last_seen) 最后一次看到的时间基本上是writetime。表中的记录数约为1000万条。 插入非常简单 insert into users (username, last_seen) VALUES ([username], now)

last_seen 列(此查询每分钟运行一次),例如:

select username from users where last_seen < (now - 1 day) 

1. 使用物化视图:

   CREATE MATERIALIZED VIEW users_last_seen AS
   SELECT last_seen, username
   FROM users
   WHERE last_seen IS NOT NULL
   PRIMARY KEY (last_seen, username);
   

   然后简单地查询

   select username from users_last_seen where last_seen < (now - 1 day)
   

2. select username from users where last_seen < (now - 1 day) ALLOW FILTERING
   

哪一个更有效?AFAIK物化视图不稳定,会影响性能。