Re: Using COPY FREEZE in pgbench

Hello,

>> After giving it some thought, ISTM that there could also be a
>> performance improvement with copy freeze from older version, so I'd
>> suggest to add it after 9.3 where the option was added, i.e. 90300.
>
> You misunderstand about COPY FREEZE. Pre-13 COPY FREEZE does not
> contribute a performance improvement. See discussions for more details.
> https://www.postgresql.org/message-id/CAMkU%3D1w3osJJ2FneELhhNRLxfZitDgp9FPHee08NT2FQFmz_pQ@mail.gmail.com
> https://www.postgresql.org/message-id/flat/CABOikdN-ptGv0mZntrK2Q8OtfUuAjqaYMGmkdU1dCKFtUxVLrg%40mail.gmail.com

Ok. ISTM that the option should be triggered as soon as it is available,
but you do as you wish.

>> Also, I do not think it is worth to fail on a 0 pqserverversion, just
>> keep the number and consider it a very old version?
>
> If pqserverversion fails, then following PQ calls are likely fail
> too. What's a benefit to continue after pqserverversion returns 0?

I'm unsure how this could happen ever. The benefit of not caring is less
lines of codes in pgbench and a later call will catch the issue anyway, if
libpq is corrupted.

>> Question: should there be a word about copy using the freeze option?
>> I'd say yes, in the section describing "g".
>
> Can you elaborate about "section describing "g"? I am not sure what
> you mean.

The "g" item in the section describing initialization steps (i.e. option
-I). I'd suggest just to replace "COPY" with "COPY FREEZE" in the
sentence.

--
Fabien.