PG-WRAPAROUND-001 · Transaction ID wraparound risk

Severity	Confidence	Permission	Applies to
Critical	Hint (age ≥ 1.5 × autovacuum_freeze_max_age) · Confirmed (age ≥ 1 billion)	public	All PostgreSQL versions and services

What it checks

age(datfrozenxid) of every database that accepts connections.

Why it matters

Near 2³¹ (≈ 2.1 billion) transaction IDs, PostgreSQL stops accepting writes to protect data. Recovery requires a long VACUUM. An age well above autovacuum_freeze_max_age means autovacuum is falling behind.

Next action

-- In the affected database: the oldest tables
SELECT c.oid::regclass, age(c.relfrozenxid) FROM pg_class c
WHERE c.relkind IN ('r', 'm', 't') ORDER BY 2 DESC LIMIT 20;

Run VACUUM (FREEZE, VERBOSE) on them and look for what blocks autovacuum: long transactions, abandoned replication slots, old prepared transactions.

Limitations

A snapshot shows the current age, not the consumption rate. How many days are left needs history.