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Message-ID: <b39d0277-de91-4fa1-b912-e3c8ee38ccf1@splendiddata.com>
Date: Wed, 2 Sep 2026 22:43:15 +0200
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Subject: Re: BUG #19647: Difference in pg_basebackup behaviour between
 PostgreSQL <= 16 and >= 17 with pgactive extension
To: Jacob Champion <jacob.champion@enterprisedb.com>
Cc: pgsql-bugs@lists.postgresql.org
References: <19647-d18354ebe2134a6d@postgresql.org>
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From: Edwin Polkerman <edwin.polkerman@splendiddata.com>
Organization: Splendid Data Nederland B.V.
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Hi Jacob,

Yes, the 18.6 and 17.11 global/ directory contains this file as well.

Doing a pg_checksums on the data directory gives exactly the same result 
as for the PostgreSQL 16.15, 15.19 and 14.24:

pg_checksums -c /var/pgpure/postgres/18/cluster2/
pg_checksums: error: invalid segment number 0 in file name 
"/var/pgpure/postgres/18/cluster2//global/pgactive.stat"

The file pgactive.stat is placed in the globals directory when the 
database server is stopped / started after installation of the extension 
and setup of the replication group. I think it is used for internal 
bookkeeping for replication statussen with the other node(s) in the 
replication group when the node is shutdown.

Because of the difference in behaviour of pg_basebackup what dazzled me, 
it made me decide to create the issue in the pgql-bugs mailing list. 
Please let me know if it is not PostgreSQL related and if it should be 
created in github at AWS/pgactive

Kind regards,
Edwin

On 9/2/26 20:51, Jacob Champion wrote:
> On Tue, Sep 1, 2026 at 6:16 AM PG Bug reporting form
> <noreply@postgresql.org> wrote:
>> For PostgreSQL 18.6 and 17.11 the backup completes without any problems.
> Do the global/ directories for the 17 and 18 clusters contain a
> pgactive.stat file?
>
> Without knowing anything about pgactive in particular (it's a
> third-party extension)... It sure looks like that extension, or else
> something related to it, has put a random file into the DB internals
> in a way that won't pass our checksum verification. It needs to go
> somewhere else.
>
> --Jacob
-- 

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    <p><font face="Liberation Sans">Hi Jacob,</font></p>
    <p><font face="Liberation Sans">Yes, the 18.6 and 17.11 global/
        directory contains this file as well.</font></p>
    <p><font face="Liberation Sans">Doing a pg_checksums on the data
        directory gives exactly the same result as for the PostgreSQL
        16.15, 15.19 and 14.24:</font></p>
    <p><font face="Liberation Sans">pg_checksums -c
        /var/pgpure/postgres/18/cluster2/<br>
        pg_checksums: error: invalid segment number 0 in file name
        "/var/pgpure/postgres/18/cluster2//global/pgactive.stat"</font></p>
    <div class="moz-cite-prefix">The file pgactive.stat is placed in the
      globals directory when the database server is stopped / started
      after installation of the extension and setup of the replication
      group. I think it is used for internal bookkeeping for replication
      statussen with the other node(s) in the replication group when the
      node is shutdown.</div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">Because of the difference in behaviour
      of pg_basebackup what dazzled me, it made me decide to create the
      issue in the pgql-bugs mailing list. Please let me know if it is
      not PostgreSQL related and if it should be created in github at
      AWS/pgactive</div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">Kind regards,</div>
    <div class="moz-cite-prefix">Edwin </div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">On 9/2/26 20:51, Jacob Champion wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAOYmi+=QyQHvH2Ehqb+Je3nvv-+Qg6Xp8fG+cNs-KwAoHvNyBA@mail.gmail.com">
      <pre wrap="" class="moz-quote-pre">On Tue, Sep 1, 2026 at 6:16 AM PG Bug reporting form
<a class="moz-txt-link-rfc2396E" href="mailto:noreply@postgresql.org">&lt;noreply@postgresql.org&gt;</a> wrote:
</pre>
      <blockquote type="cite">
        <pre wrap="" class="moz-quote-pre">For PostgreSQL 18.6 and 17.11 the backup completes without any problems.
</pre>
      </blockquote>
      <pre wrap="" class="moz-quote-pre">
Do the global/ directories for the 17 and 18 clusters contain a
pgactive.stat file?

Without knowing anything about pgactive in particular (it's a
third-party extension)... It sure looks like that extension, or else
something related to it, has put a random file into the DB internals
in a way that won't pass our checksum verification. It needs to go
somewhere else.

--Jacob
</pre>
    </blockquote>
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