How Do Dynamic Fields Impact MAR?

Some historical tables (e.g., ACCOUNT_HISTORY table) contain both static fields, such as business_city and currency, and dynamic fields, which are updated more often, such as amount_spent and balance. Fivetran generates a unique fivetran_id column based on all fields in the record. This means that whenever a dynamic field changes, we create a new fivetran_id column, resulting in a new version of the record. Because the REACH_FREQUENCY table references ACCOUNT_HISTORY by its fivetran_id, any update to ACCOUNT_HISTORY causes the related reach_frequency rows to be rewritten as well. For active accounts, this can significantly increase your Monthly Active Rows (MAR) usage.

To reduce MAR usage, consider adjusting your Facebook Ads connection's sync frequency to reduce how often dynamic fields are refreshed.