滚动窗口

   
   


    
    
TUMBLE(<time-attr>, <size-interval>)

    
    
<size-interval>: INTERVAL 'string' timeUnit
   
   

   
   


    
    
CREATE TABLE user_clicks(

    
    
username varchar,

    
    
click_url varchar,

    
    
ts timeStamp,

    
    
WATERMARK wk FOR ts as withOffset(ts, 2000) -- 为rowtime定义watermark

    
    
) with (

    
    
type='datahub',

    
    
...

    
    
);

    
    
CREATE TABLE tumble_output(

    
    
window_start TIMESTAMP,

    
    
window_end TIMESTAMP,

    
    
username VARCHAR,

    
    
clicks BIGINT

    
    
) with (

    
    
type='RDS'

    
    
);

    
    
INSERT INTO tumble_output

    
    
SELECT

    
    
TUMBLE_START(ts, INTERVAL '1' MINUTE),

    
    
TUMBLE_END(ts, INTERVAL '1' MINUTE),

    
    
username,

    
    
COUNT(click_url)

    
    
FROM window_input

    
    
GROUP BY TUMBLE(ts, INTERVAL '1' MINUTE), username