Re: Up to 50x degradation in dblink performance when receiving notice traffic 19 vs 18 - Mailing list pgsql-hackers

From Merlin Moncure
Subject Re: Up to 50x degradation in dblink performance when receiving notice traffic 19 vs 18
Date
Msg-id CAHyXU0za3SOgUGSBLUxxyyywk2LpG6MoB8t3V7Wng-ni9O9z6Q@mail.gmail.com
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In response to Re: Up to 50x degradation in dblink performance when receiving notice traffic 19 vs 18  (Merlin Moncure <mmoncure@gmail.com>)
List pgsql-hackers
On Thu, Sep 24, 2026 at 8:50 AM Merlin Moncure <mmoncure@gmail.com> wrote:

My work on adding a WaitEventSet based dblink API poll was in part inspired by attempting to defend against this issue on the premise that sitting around in poll() and being aggressive with consumeinput vs pg_sleep latch was somehow more polite to the o/s somehow.  Perhaps it's not a bug at all, but a simple hardware flush problem that postgres is at the mercy of.

Quick note: turning off logging collector, then disconnecting the session that invoked pg_ctl so that logs go nowhere, timings go flat and are fast.   So this smells like hardware.

merlin

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