limitation of WHERE clause

[Jayko001]

(not really a bug): does not handle expressions (is this normal for FDW? how would we handle this? can it do better error message?)

-- e.g. this would not work:
SELECT
  *
FROM metrics
WHERE
  metric_name = 'container_cpu_usage_seconds_total'
  AND metric_time > EXTRACT(EPOCH FROM NOW() - INTERVAL '500 seconds')
  AND metric_time < EXTRACT(EPOCH FROM NOW());

-- this would work
SELECT
  *
FROM metrics
WHERE
  metric_name='container_cpu_usage_seconds_total'
  AND metric_time > 1702060087 AND metric_time < 1702062087;