Optimization: Better Replication Lag Monitor Query

Choose the better query for replication lag monitoring and provide final SQL. Query A: SELECT replica_id, MAX(NOW() - apply_time) AS lag FROM replica_apply_log GROUP BY replica_id; Query B: SELECT replica_id, EXTRACT(EPOCH FROM (CURRENT_TIMESTAMP - MAX(apply_time))) AS lag_seconds FROM replica_apply_log WHERE apply_time >= CURRENT_TIMESTAMP - INTERVAL '1 hour' GROUP BY replica_id;

replica_apply_log(replica_id, apply_time, lsn)