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Re: walsummarizer can get stuck when switching timelines - Mailing list pgsql-hackers

From Robert Haas
Subject Re: walsummarizer can get stuck when switching timelines
Date
Msg-id CA+TgmoZwZ8mgysY_yTP-s3U5VtfqJS9d4JVKBOXvshmVvC-1vQ@mail.gmail.com
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In response to Re: walsummarizer can get stuck when switching timelines  (Thom Brown <thom@linux.com>)
Responses Re: walsummarizer can get stuck when switching timelines
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On Thu, Jul 16, 2026 at 8:59 AM Thom Brown <thom@linux.com> wrote:
> Well if we run pg_switch_wal(), we're effectively closing the current
> segment. CHECKPOINT then emits its WAL after the switch. If the
> summarizer needs a CHECKPOINT_REDO record in the segment being
> archived, it would already be too late.

OK, I think this is where we're seeing things differently. The
summarizer doesn't need a CHECKPOINT_REDO record in the segment being
archived. Rather, we need a CHECKPOINT_REDO record somewhere after the
WAL that we want summarized. In this case, the WAL we want summarized
is generated by the pg_switch_wal() call.

--
Robert Haas
EDB: http://www.enterprisedb.com

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