Re: [Sender Address Forgery]Re: Postgres 11 release notes

On 2018/05/23 10:16, Bruce Momjian wrote:
> On Sat, May 19, 2018 at 12:58:04AM +0900, Amit Langote wrote:
>> Hi Bruce.
>>
>> On Tue, May 15, 2018 at 12:46 PM, Amit Langote
>> <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
>>> On 2018/05/15 5:30, Bruce Momjian wrote:
>>>> I like it, done.
>>>
>>> Thank you.
>>
>> I wonder what you think about including this little performance item:
>>
>> https://www.postgresql.org/message-id/E1eotSQ-0005V0-LV@gemulon.postgresql.org
>>
>> especially considering the part of the commit message which states
>>
>> ...Still, testing shows
>> that this makes single-row inserts significantly faster on a table
>> with many partitions without harming the bulk-insert case.
>>
>> I recall seeing those inserts being as much as 2x faster as partition
>> count grows beyond hundreds. One might argue that we should think
>> about publicizing this only after we've dealt with the
>> lock-all-partitions issue that's also mentioned in the commit message
>> which is still a significant portion of the time spent and I'm totally
>> fine with that.
>
> Uh, we already have this in the release notes:
>
> Allow faster partition elimination during query processing (Amit
> Langote, David Rowley, Dilip Kumar)
>
> This speeds access to partitioned tables with many partitions.
>
> Do you want me to add the git commit hash to this release note entry?

I suppose you meant the above as an entry for performance improvement of
partition "pruning". The commit I quoted is concerned with making "tuple
routing" a bit faster, but as David said that's not making it as fast as
it could really be. So, we should hold off from touting it as an
improvement at this point and I have to agree. Sorry for the noise.

Thanks,
Amit