Re: ALTER SYSTEM SET command to change postgresql.conf parameters (RE: Proposal for Allow postgresql.conf values to be changed via SQL [review])

On Mon, Nov 18, 2013 at 8:31 PM, Haribabu kommi
<haribabu(dot)kommi(at)huawei(dot)com> wrote:
> On 18 November 2013 20:01 Amit Kapila wrote:
>> > Code changes are fine.
>> > If two or three errors are present in the configuration file, it
>> prints the last error
>> > Configuration parameter file only. Is it required to be mentioned in
>> the documentation?
>>
>> Do you mean to say parsing errors or some run-time error, could you
>> explain with example?
>
> LOG: parameter "shared_buffers" cannot be changed without restarting the server
> LOG: parameter "port" cannot be changed without restarting the server
> LOG: configuration file "/home/hari/installation/bin/../../data/postgresql.auto.conf" contains errors; unaffected changes were applied
>
> The shared_buffers parameter is changed in postgresql.conf and port is changed in postgresql.auto.conf.
> The error file displays the last error occurred file.

This is only possible if user tries to change configuration
parameters both by Alter System command and manually as well and the
case above is
not an error, it is just an information for user that there are
some parameters changed in config file which can only get reflected
after server restart.
So definitely user can check log files to see which parameter's
doesn't get reflected if he is expecting some parameter to be changed,
but it's not
changed. I think here even in logs if last file containing errors
is mentioned is not a big problem.

> Is it required to mention the above behavior in the document?

It is better to show in log both the files rather than documenting
it, if the the above case is helpful for user which I don't think so,
also to handle case
in code can complicate the error handling path of code a bit. So I
think we can leave this case as-is.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com