The exceptional time traveler
What changed? This a question that’s been asked since the first data manipulation language (DML) operations were performed on a database. While Snowflake’s built-in table change tracking and streams can help answer this question, they are not enabled on tables by default. However, even in Snowflake’s Standard edition, all tables have a default time travel data retention period of one day.
The time travel feature can be combined with the EXCEPT set operator to isolate and compare any changes made. The exercise uses a randomly generated filter when selecting which records to update to make things interesting. The only way to solve the mystery is to use Snowflake’s exceptional time-traveling powers.
The exercise is explained in the file titled 01_exceptional_time_travel.sql.
