Question 12 asked whether to add a quality-of-service dimension. No - because
we could not enforce it. Community PostgreSQL has no resource governor, so a
declared priority would be an unenforced claim in a declaration, which is what
retiring tenantIsolation was about. An axis implies graduation and enforcement
and this has neither.
Co-residents are equal, and a consumer whose latency cannot survive an
unprioritised neighbour escalates to P2. Service class is still declared, as a
category not a level: it informs placement, acts as a trigger, and gives
"acceptable degradation" in the noisy-neighbour artifact something to be
acceptable relative to - what batch tolerates is an outage for latency-critical.
Class mixture must be visible, because an unenforceable risk nobody can see is
worse than one that is stated. rapp-postgres now reports it and the live
instance already flags latency-critical beside batch.
Gateway-level prioritisation in a connection proxy is recorded as the known
escalation short of P2 - real, and infrastructure we do not run.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
tegwick
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