Periodic Snapshot vs Additive

Periodic snapshot fact and additive fact are different concepts, although they may appear similar at first glance.

A periodic snapshot fact table is designed to capture a point-in-time snapshot of some measure at regular intervals, typically periodically, such as daily, weekly, monthly, or quarterly.

An additive fact represents a measure that can be aggregated across all dimensions in a fact table. For example, sales revenue is an additive fact because it can be summed up across all dimensions such as time, product, region, etc.

	Additive Fact	Periodic Snapshot Fact
Definition	Represents a measure that can be aggregated across all dimensions in a fact table	Captures a point-in-time snapshot of some measure at regular intervals
Granularity	Can be at any level of granularity	Usually at a higher level of granularity such as daily, weekly, monthly, or quarterly
Aggregation	Can be summed up across all dimensions in the fact table	Captures the total value of the measure at a specific point in time
Example	Sales revenue, profit, number of clicks on a banner ad	Monthly sales revenue, quarterly website visits, daily customer support tickets