Re: Inconsistency in determining the timestamp of the db statfile.

On Wed, Sep 09, 2020 at 03:53:40PM +0530, Amit Kapila wrote:
>On Wed, Sep 9, 2020 at 3:15 PM Magnus Hagander  wrote:
>>
>> On Wed, Sep 9, 2020 at 5:04 AM Amit Kapila  wrote:
>>>
>>
>> Though in fact the one inconsistent place in the code now is that if it is corrupt in the db entry part of the file it returns true and the global timestamp, which I would argue is perhaps incorrect and it should return false.
>>
>
>Yeah, this is exactly the case I was pointing out where we return true
>before the patch, basically the code below:
>case 'D':
>if (fread(&dbentry, 1, offsetof(PgStat_StatDBEntry, tables),
>  fpin) != offsetof(PgStat_StatDBEntry, tables))
>{
>ereport(pgStatRunningInCollector ? LOG : WARNING,
>(errmsg("corrupted statistics file \"%s\"",
>statfile)));
>goto done;
>}
>
>done:
>FreeFile(fpin);
>return true;
>
>Now, if we decide to return 'false' here, then surely there is no
>argument and we should return false in other cases as well. Basically,
>I think we should be consistent in handling the corrupt file case.
>

FWIW I do agree with this - we should return false here, to make it
return false like in the other data corruption cases. AFAICS that's the
only inconsistency here.


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services