创建还是替换？

create or replace view testv as select 1;
create or replace view testv as select 2;
select * from testv
┌─2─┐
│ 2 │
└───┘

https://github.com/clickhouse/clickhouse/blob/master/docs/en/whats-new/changelog/2019.md

ClickHouse Release 19.5.2.6, 2019-04-15
   Support for CREATE OR REPLACE VIEW. 
   Allow to create a view or set a new definition in a 
   single statement. #4654 (Boris Granveaud)