Hive query generating identifiers for a sequence of row matching a condition

Question

Let\'s say I have the following hive table as input, let\'s call it connections:

userid  | timestamp   
--------|-------------
1       | 1433258019          


        

Answer 1

This works:

SELECT 
  userid,
  timestamp,
  timediff,
  CONCAT(
    'user',
     userid,
     '-',
     'session-',
     CAST(timediff / 60 AS INT) + 1
  ) AS session_id
  FROM (
    SELECT   
      userid,
      timestamp,
      timestamp - LAG(timestamp, 1, timestamp) OVER w AS timediff
    FROM connections
    WINDOW w AS (
      PARTITION BY userid
      ORDER BY timestamp ASC
    )
) a;

OUTPUT:

userid  timestamp   timediff    session_state
1       1433258019  0.0         user1-session-1
1       1433258020  1.0         user1-session-1
2       1433258080  0.0         user2-session-1
2       1433258083  3.0         user2-session-1
2       1433258088  5.0         user2-session-1
2       1433258170  82.0        user2-session-2
3       1433258270  0.0         user3-session-1

you can try something like this if timediff is not required:

select userid,timestamp ,session_count+ concat('user',userid,'-','session-',cast(LAG(session_count-1,1,0) over w1 as string)) AS session_state
--LAG(session_count-1,1,0) over w1 AS session_count_new FROM (select userid, timestamp, timediff, cast (timediff/60 as int)+1 as session_count