1.SQL: **d_customers** +-------------+-----------------------+---------------------+ | customer_id | membership_start_date | membership_end_date | +-------------+-----------------------+---------------------+ | 114 | 2015-01-01 | 2015-02-15 | | 116 | 2015-02-01 | 2015-03-15 | | 120 | 2015-02-15 | 2015-04-01 | | 221 | 2015-03-15 | 2015-10-01 | | 120 | 2015-05-15 | 2015-07-01 | +-------------+-----------------------+---------------------+ **d_shipments** +-------------+------------+-----------------------+----------+ | shipment_id | ship_date | receiving_customer_id | quantity | +-------------+------------+-----------------------+----------+ | 1 | 2015-02-13 | 114 | 2 | | 2 | 2015-03-01 | 116 | 4 | | 2 | 2015-03-01 | 116 | 1 | | 3 | 2015-06-01 | 116 | 1 | | 4 | 2015-03-01 | 120 | 6 | | 5 | 2015-10-01 | 120 | 3 | | 6 | 2015-03-01 | 321 | 10 | +-------------+------------+-----------------------+----------+ Populate **a_shipments** +-----------+-----------+----------+----------+----------+ | ship_date | customer_id | is_member | quantity | +-----------+-----------+----------+----------+----------+ the column [is_member]: if [ship_date] is between [membership_start_date] and [membership_end_date] then 'y', else 'N' sample of otput: 2015-03-01 | 116 | Y | 5 | 2015-06-01 | 116 | N | 1 | 2. Coding task. Check whether a string is palindrome. I have been asked to code a solution by iterative and recursive approach. 3. Big Data questions: 3.1. What format of files in Hadoop do I know? What is a difference between Avro and Parquet format? 3.2. How compression is used in Avro and Parquet formats? 3.3. Most difficult big data performance challenges you have faced and resolved? 3.4. Spark optimization. Spark cost based optimizer