title: Insert data of 2 Hive external tables in new External table with additional column
body: <p>I have 2 external hive tables as follows. I have populated data in them from oracle using sqoop. </p>
  
  <pre><code>create external table transaction_usa
  (
  tran_id int,
  acct_id int,
  tran_date string,
  amount double,
  description string,
  branch_code string,
  tran_state string,
  tran_city string,
  speendby string,
  tran_zip int
  )
  row format delimited
  stored as textfile
  location '/user/stg/bank_stg/tran_usa';
  
  create external table transaction_canada
  (
  tran_id int,
  acct_id int,
  tran_date string,
  amount double,
  description string,
  branch_code string,
  tran_state string,
  tran_city string,
  speendby string,
  tran_zip int
  )
  row format delimited
  stored as textfile
  location '/user/stg/bank_stg/tran_canada';
  </code></pre>
  
  <p>Now i want to merge above 2 tables data as it is in 1 external hive table with all same fields as in the above 2 tables but with 1 extra column to identify that which data is from which table. The new external table with additional column as <code>source_table</code>. The new external table is as follows.</p>
  
  <pre><code>create external table transaction_usa_canada
  (
  tran_id int,
  acct_id int,
  tran_date string,
  amount double,
  description string,
  branch_code string,
  tran_state string,
  tran_city string,
  speendby string,
  tran_zip int,
  source_table string
  )
  row format delimited
  stored as textfile
  location '/user/gds/bank_ds/tran_usa_canada';
  </code></pre>
  
  <p>how can I do it.?</p>