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A satellite television provider XYZ is looking forward to your help in retrieving some critical information from its data warehouse. The satellite television provider provides television channels bundled in packages to its subscribers. The below diagram explains the key data tables and the relation-ship between them: [Don't have diag] D_SUBSCRIBER is a dimension table that has details of subscribers (customers). D_PACKAGES is a dimension table that has details of various package offered by the provider F_SUBSCRIPTIONS is a fact table that stores package subscriptions by each subscriber. A subscriber can have multiple records in this table during his lifetime Please note the following business rules • There are 2 types of packages. BASE pack and ADDON pack (which is mentioned in PACKAGE_TYPE attribute) • Subscriber will have at least 1 BASE pack. They can have 0 or more ADDON packs • A package is considered active for a subscriber if PACKAGE_SUB_END_DT in F_SUBSCRIPTIONS is NULL. Otherwise the package is not active for the subscriber • A subscriber is considered to be active if there is a BASE pack linked to him with NULL PACKAGE_SUB_END_DT. Otherwise the subscriber is considered to be inactive. • Each package has a PRICE_PER_DAY which is the fee for the package for a single day usage. A subscriber’s monthly fee is the PRICE_PER_DAY of each of his active packages multiplied by No. of active days in that month that he has been on that package. The fee is considered as revenue to the business. Please find below sample data for each tables for better understanding • D_SUBSCRIBER D_SUBSCRIBER_ID SUBSCRIBER_NAME SUBSCRIBER_JOINING_DT 1E+08 Rahul Agarwal ######## 1E+08 Ajay Mehta ######## 1E+08 Pranab Shetty ######## • D_PACKAGES D_PACKAGE_ID PACKAGE_NAME PACKAGE_TYPE PRICE_PER_DAY 131 Metro Base ₹ 4 132 Dhamaal Cricket Base ₹ 5 133 South Special Base ₹ 4 134 Supreme Kids Base ₹ 3 231 Hindi Movies Addon ₹ 1 232 English News Addon ₹ 2 233 English Entertainment Addon ₹ 2 • F_SUBSCRIPTIONS D_SUBSCRIBER_ID D_PACKAGE_ID PACKAGE_START_DT PACKAGE_END_DT 1E+08 131 ######## 1E+08 231 ######## 19-Jan-15 1E+08 233 ######## 1E+08 133 ######## 1-Jun-15 1E+08 232 17-Jan-15 1-Mar-15 1E+08 131 ######## The business relies on you to pull out important data to get better understanding of the business and subscriber’s. For each of the questions below please write a SQL query. Please follow the below ground rules for answering the below questions 1) The marketing team wants to run a campaign to bring back subscribers who are no longer active. Write a query to pull out subscribers who are no longer active? 2) The products team wants to understand subscribers who have at least 2 Add on Packages. Write a query to pull out subscribers who have at least 2 active ADDON pack? 3) The marketing team believes that people who subscribe to ‘English News’ package should also be needing ‘English Entertainment’ package. Write a SQL to pull out subscribers who have active ‘English News’ package but do not have active ‘English Entertainment’ package 4) The finance team wants to track revenue generated by each subscriber. 5) Write a SQL to get total revenue generated by each subscriber in the year 2014? 6) Write a query to identify Top 3 base packages (in terms of revenue collected) for each month in 2014?
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Data Engineer

Interviewed at Amazon

3.5★
Jan 13, 2021

A satellite television provider XYZ is looking forward to your help in retrieving some critical information from its data warehouse. The satellite television provider provides television channels bundled in packages to its subscribers. The below diagram explains the key data tables and the relation-ship between them: [Don't have diag] D_SUBSCRIBER is a dimension table that has details of subscribers (customers). D_PACKAGES is a dimension table that has details of various package offered by the provider F_SUBSCRIPTIONS is a fact table that stores package subscriptions by each subscriber. A subscriber can have multiple records in this table during his lifetime Please note the following business rules • There are 2 types of packages. BASE pack and ADDON pack (which is mentioned in PACKAGE_TYPE attribute) • Subscriber will have at least 1 BASE pack. They can have 0 or more ADDON packs • A package is considered active for a subscriber if PACKAGE_SUB_END_DT in F_SUBSCRIPTIONS is NULL. Otherwise the package is not active for the subscriber • A subscriber is considered to be active if there is a BASE pack linked to him with NULL PACKAGE_SUB_END_DT. Otherwise the subscriber is considered to be inactive. • Each package has a PRICE_PER_DAY which is the fee for the package for a single day usage. A subscriber’s monthly fee is the PRICE_PER_DAY of each of his active packages multiplied by No. of active days in that month that he has been on that package. The fee is considered as revenue to the business. Please find below sample data for each tables for better understanding • D_SUBSCRIBER D_SUBSCRIBER_ID SUBSCRIBER_NAME SUBSCRIBER_JOINING_DT 1E+08 Rahul Agarwal ######## 1E+08 Ajay Mehta ######## 1E+08 Pranab Shetty ######## • D_PACKAGES D_PACKAGE_ID PACKAGE_NAME PACKAGE_TYPE PRICE_PER_DAY 131 Metro Base ₹ 4 132 Dhamaal Cricket Base ₹ 5 133 South Special Base ₹ 4 134 Supreme Kids Base ₹ 3 231 Hindi Movies Addon ₹ 1 232 English News Addon ₹ 2 233 English Entertainment Addon ₹ 2 • F_SUBSCRIPTIONS D_SUBSCRIBER_ID D_PACKAGE_ID PACKAGE_START_DT PACKAGE_END_DT 1E+08 131 ######## 1E+08 231 ######## 19-Jan-15 1E+08 233 ######## 1E+08 133 ######## 1-Jun-15 1E+08 232 17-Jan-15 1-Mar-15 1E+08 131 ######## The business relies on you to pull out important data to get better understanding of the business and subscriber’s. For each of the questions below please write a SQL query. Please follow the below ground rules for answering the below questions 1) The marketing team wants to run a campaign to bring back subscribers who are no longer active. Write a query to pull out subscribers who are no longer active? 2) The products team wants to understand subscribers who have at least 2 Add on Packages. Write a query to pull out subscribers who have at least 2 active ADDON pack? 3) The marketing team believes that people who subscribe to ‘English News’ package should also be needing ‘English Entertainment’ package. Write a SQL to pull out subscribers who have active ‘English News’ package but do not have active ‘English Entertainment’ package 4) The finance team wants to track revenue generated by each subscriber. 5) Write a SQL to get total revenue generated by each subscriber in the year 2014? 6) Write a query to identify Top 3 base packages (in terms of revenue collected) for each month in 2014?

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