Re: pgsql: Parameter toast_tuple_target controls TOAST for new rows

On 19 November 2017 at 19:52, Andres Freund <andres(at)anarazel(dot)de> wrote:
> On 2017-11-19 19:49:01 -0500, Tom Lane wrote:
>> Andres Freund <andres(at)anarazel(dot)de> writes:
>> > On 2017-11-19 19:08:48 -0500, Simon Riggs wrote:
>> >> Am investigating the few buildfarm failures
>>
>> > The tests look very sensitive to differences in tuple size due to
>> > different alignment requirements. Dependant on what MAXALIGN (and some
>> > others) is the number of tuples fitting on a page will differ.
>>
>> "Few" buildfarm failures? It's probably going to fail on every 32-bit host.
>>
>> TBH, I would just remove those test cases. Even if they were stable
>> across platforms, they don't directly prove anything at all about
>> whether the feature does what it's supposed to.
>>
>> (Also, scaling the results to blocksize seems unlikely to help in
>> passing on different BLCKSZ configurations...)
>
> I think it might make sense to rewrite the tests so it doesn't output
> any of the sizes, but instead just compares the size of tables with
> different thresholds. That should be fairly reliable.

Thanks for your input.

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