21Implement Slowly Changing Dimension Type 2, keep full history when a customer's attributes change.▼hardSnowflakeDatabricksMicrosoft2 replies◆ premiumEveryone can define SCD2; very few can write the MERGE that maintains it correctly. The expire-and-insert dance, the one-statement trick, and the late-arriving-change trap that breaks naive implementations.Open full answer →
40Model a dimension bitemporally so you can answer 'what did we believe the customer's plan was, as of last Tuesday?'▼hardPalantirSnowflakeDatabricks1 replies◆ premiumSCD2 tracks when an attribute was true; bitemporal also tracks when you knew it. The question separates engineers who can audit a number from those who quietly overwrite history when a correction arrives.Open full answer →
