Why Is the XMIN Wraparound Causing MAR Spikes?

MAR increases may occur only on accounts who have signed annual contracts before March 1, 2025. Customers who have signed up for Fivetran after March 1, 2025, do not experience this MAR increase.

Issue

The value of the xmin column has an upper limit of 4,294,967,295. After the database's total number of transactions exceeds this value, it "wraps around" to zero. After this event occurs in PostgreSQL versions 9.5 and later, multiple rows may have the same xmin value and Fivetran may additionally sync older, unchanged "frozen" rows, resulting in a MAR spike and higher costs.

Environment

Connector: PostgreSQL
Sync method: Query-Based

Resolution

We recommend switching to logical replication as your incremental sync method.

Logical replication provides continuous, efficient change data capture and isn’t affected by XMIN wraparound. For more information, see our Switching from Query-Based to Logical Replication documentation.