On Wed, Mar 18, 2026 at 7:36 AM Andrei Lepikhov <lepihov@gmail.com> wrote:
On 18/3/26 15:26, Andres Freund wrote: > Regardless of the AI angle it's quite useful to be able to put a server into > read only mode, e.g. in preparation for a planned failover where you can > continue to allow reads but don't want any more writes. Or in preparation for > a shutdown you want to prevent further writes (so the shutdown checkpoint is > quick), but you do want to allow further reads (to reduce the scope of the > downtime, by allowing reads while doing a CHECKPOINT before the actual > shutdown).
It returns us to the question about cluster-wide V/S session-wide read-only mode. Should we design one of them or consider both? What do you think?
+1 to scenarios Andres' mentioned. Additional cases where a cluster‑wide setting is helpful include disk‑full events and policy enforcement, where write access is revoked but read access is preserved for data exfiltration. Session level is helpful for the AI use cases or to provide controlled user access. I see value in supporting both.
