DROP TABLE IF EXISTS customer;
DROP TABLE IF EXISTS orders;
DROP TABLE IF EXISTS q13_customer_distribution;

-- create the tables and load the data
create external table customer (C_CUSTKEY INT, C_NAME STRING, C_ADDRESS STRING, C_NATIONKEY INT, C_PHONE STRING, C_ACCTBAL DOUBLE, C_MKTSEGMENT STRING, C_COMMENT STRING) ROW FORMAT DELIMITED FIELDS TERMINATED BY '|' STORED AS TEXTFILE LOCATION '/tpch/customer';
create external table orders (O_ORDERKEY INT, O_CUSTKEY INT, O_ORDERSTATUS STRING, O_TOTALPRICE DOUBLE, O_ORDERDATE STRING, O_ORDERPRIORITY STRING, O_CLERK STRING, O_SHIPPRIORITY INT, O_COMMENT STRING) ROW FORMAT DELIMITED FIELDS TERMINATED BY '|' STORED AS TEXTFILE LOCATION '/tpch/orders';

-- create the result table
create table q13_customer_distribution (c_count int, custdist int);

-- the query
insert overwrite table q13_customer_distribution
select 
  c_count, count(1) as custdist
from 
  (select 
     c_custkey, count(o_orderkey) as c_count
   from 
     customer c left outer join orders o 
     on 
       c.c_custkey = o.o_custkey and not o.o_comment like '%special%requests%'
   group by c_custkey
   ) c_orders
group by c_count
order by custdist desc, c_count desc;