SQL Q&A Sol 1 Execution time compare: https://www.evernote.com/shard/s640/sh/6c52ccce-1265-466c-81f0-9c64cea008b8/dc0ca27aab5d16ea8b432a3be9877d98
New_users | churn: https://www.evernote.com/shard/s640/sh/914d5637-5c27-4cc0-8aa5-3f131704d1c0/64c2b7aca35affa14589b4e96e1c3214