Re: Timeline ID hexadecimal format

On 02/03/2023 09:12, Peter Eisentraut wrote:
> On 24.02.23 17:27, Sébastien Lardière wrote:
>> diff --git a/doc/src/sgml/backup.sgml b/doc/src/sgml/backup.sgml
>> index be05a33205..7e26b51031 100644
>> --- a/doc/src/sgml/backup.sgml
>> +++ b/doc/src/sgml/backup.sgml
>> @@ -1332,7 +1332,8 @@ restore_command = 'cp/mnt/server/archivedir/%f %p'
>>       you like, add comments to a history file to record your own
>> notes about
>>       how and why this particular timeline was created.  Such
>> comments will be
>>       especially valuable when you have a thicket of different
>> timelines as
>> -    a result of experimentation.
>> +    a result of experimentation. In both WAL segment file names and
>> history files,
>> +    the timeline ID number is expressed in hexadecimal.
>>      </para>
>>        <para>
>
> I think here it would be more helpful to show actual examples. Like,
> here is a possible file name, this is what the different parts mean.

So you mean explain the WAL filename and the history filename ? Is it
the good place for it ?

>
>> diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
>> index e5c41cc6c6..3b5d041d92 100644
>> --- a/doc/src/sgml/config.sgml
>> +++ b/doc/src/sgml/config.sgml
>> @@ -4110,7 +4110,9 @@ restore_command = 'copy
>> "C:\\server\\archivedir\\%f" "%p"'  # Windows
>>           current when the base backup was taken.  The
>>           value <literal>latest</literal> recovers
>>           to the latest timeline found in the archive, which is
>> useful in
>> -        a standby server. <literal>latest</literal> is the default.
>> +        a standby server. A numerical value expressed in hexadecimal
>> must be
>> +        prefixed with <literal>0x</literal>, for example
>> <literal>0x11</literal>.
>> +        <literal>latest</literal> is the default.
>>          </para>
>>            <para>
>
> This applies to all configuration parameters, so it doesn't need to be
> mentioned explicitly for individual ones.

Probably, but is there another parameter with the same consequence ?

worth it to document this point globally ?

>
>> diff --git a/doc/src/sgml/ref/pg_waldump.sgml
>> b/doc/src/sgml/ref/pg_waldump.sgml
>> index 343f0482a9..4ae8f2ebdd 100644
>> --- a/doc/src/sgml/ref/pg_waldump.sgml
>> +++ b/doc/src/sgml/ref/pg_waldump.sgml
>> @@ -215,7 +215,8 @@ PostgreSQL documentation
>>          <para>
>>           Timeline from which to read WAL records. The default is to
>> use the
>>           value in <replaceable>startseg</replaceable>, if that is
>> specified; otherwise, the
>> -        default is 1.
>> +        default is 1. The value must be expressed in decimal,
>> contrary to the hexadecimal
>> +        value given in WAL segment file names and history files.
>>          </para>
>>         </listitem>
>>        </varlistentry>
>
> Maybe this could be fixed instead?
>
>

Indeed, and strtoul is probably a better option than sscanf, don't you
think ?

--
Sébastien