Hi Nitin, 
It seems to have been filtered out.  

> On Nov 5, 2019, at 8:29 AM, Nitin Pawar <nitinpawar...@gmail.com> wrote:
> 
> Hi Charles,
> 
> I have attached git patch. 
> I was currently doing for lag function only for testing purposes 
> 
> Thanks,
> Nitin 
> 
> On Tue, Nov 5, 2019 at 6:34 PM Charles Givre <cgi...@gmail.com 
> <mailto:cgi...@gmail.com>> wrote:
> Hi Nitin, 
> Thanks for your question.  Could you/did you share your code?  If not, could 
> you please post a draft PR so that we can take a look and offer suggestions?
> Thanks,
> -- C
> 
> 
> > On Nov 5, 2019, at 7:27 AM, Nitin Pawar <nitinpawar...@gmail.com 
> > <mailto:nitinpawar...@gmail.com>> wrote:
> > 
> > Hi Devs,
> > 
> > I had sent request for this almost 2.5 years ago. Trying it again now.
> > 
> > Currently Apache drill window functions LEAD and LAG support offset as 1.
> > In another words in a given window these functions can return either
> > previous or next row only.
> > 
> > 
> > I am trying modify the behavior these function and allow offset >=1 in
> > query such as
> > select employee_id, department_id,salary, lag(salary,*4*) over(partition by
> > department_id order by salary asc) from  cp.`employee.json`;
> > 
> > I have managed to remove the limitation which fails the query can not have
> > offset > 1 and able to pass the offset to actual function implementation.
> > 
> > Currently I am stuck where the record processor is crossing the window
> > boundary of department_id and gets row from next/previous window in
> > lead/lag function
> > 
> > For eg: If you notice in row 2 for department_id=2, it is getting previous
> > windows of department_id=1
> > 
> > Here is sample output for below query
> > apache drill> select  employee_id, department_id,salary, lag(salary,4)
> > over(partition by department_id order by salary asc) from
> > cp.`employee.json` where department_id <=3;
> > +-------------+---------------+---------+----------+
> > | employee_id | department_id | salary  |  EXPR$3  |
> > +-------------+---------------+---------+----------+
> > | 20          | 1             | 30000.0 | null     |
> > | 5           | 1             | 35000.0 | null     |
> > | 22          | 1             | 35000.0 | null     |
> > | 21          | 1             | 35000.0 | null     |
> > | 2           | 1             | 40000.0 | 30000.0  |
> > | 4           | 1             | 40000.0 | 35000.0  |
> > | 1           | 1             | 80000.0 | 35000.0  |
> > | 37          | 2             | 6700.0  | null     |
> > | 38          | 2             | 8000.0  | 40000.0  |
> > | 39          | 2             | 10000.0 | 40000.0  |
> > | 40          | 2             | 10000.0 | 80000.0  |
> > | 6           | 2             | 25000.0 | 6700.0   |
> > | 42          | 3             | 5000.0  | null     |
> > | 41          | 3             | 8500.0  | 10000.0  |
> > | 7           | 3             | 15000.0 | 10000.0  |
> > | 36          | 3             | 45000.0 | 25000.0  |
> > +-------------+---------------+---------+----------+
> > 
> > 
> > Thanks,
> > Nitin Pawar
> 
> 
> 
> -- 
> Nitin Pawar

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