problem with IS NOT NULL operator in hive

[prakash sejwani]

Hi all,
      I have a query below

FROM (
  SELECT h.*
  FROM (
      -- Pull from the access_log
      SELECT ip,
        -- Reformat the time from the access log
        time, dt,
        --method, resource, protocol, status, length, referer, agent,
        -- Extract the product_id for the hit from the URL
        cast( regexp_extract(resource,'\&q=([^\&]+)', 1) AS STRING) AS
product_name
      FROM a_log
    ) h
)hit
    -- Insert the hit data into a seperate search table
INSERT OVERWRITE TABLE search
  SELECT ip, time, dt,
    product_name
WHERE product_name IS NOT NULL;


it suppose to populate the search table with only if product_name is present
but i get all of it..

any help would be appreciated

thanks
prakash sejwani
econify infotech
mumbai