Hive summary function inside case statement - sql

Question

I am trying to write a simple Hive query:
select sum(case when pot_sls_q > 2* avg(pit_sls_q) then 1 else 0)/count(*) from prd_inv_fnd.item_pot_sls where dept_i=43 and class_i=3 where p_wk_end_d = 2014-06-28;
Here pit_sls_q and pot_sls_q both are columns in the Hive table and I want proportion of records which have pot_sls_q more than 2 times average of pit_sls_q. However I get error:
FAILED: SemanticException [Error 10128]: Line 1:95 Not yet supported place for UDAF 'avg'
To fool around I even tried using some window function:
select sum(case when pot_sls_q > 2* avg(pit_sls_q) over (partition by dept_i,class_i) then 1 else 0 end)/count(*) from prd_inv_fnd.item_pot_sls where dept_i=43 and class_i=3 and p_wk_end_d = '2014-06-28';
which is fine considering the fact filtering or partitioning the data on same condition is "same" data essentially but even with this I get error:
FAILED: SemanticException [Error 10002]: Line 1:36 Invalid column reference 'avg': (possible column names are: p_wk_end_d, dept_i, class_i, item_i, pit_sls_q, pot_sls_q)
please suggest right way of doing this.

Answer 1

You are using AVG inside SUM which won't work (along with other syntax errors).
Try analytic AVG OVER () this:
select sum(case when pot_sls_q > 2 * avg_pit_sls_q then 1 else 0 end) / count(*)
from (
select t.*,
avg(pit_sls_q) over () avg_pit_sls_q
from prd_inv_fnd.item_pot_sls t
where dept_i = 43
and class_i = 3
and p_wk_end_d = '2014-06-28'
) t;