Re: more detailed description of tup_returned and tup_fetched

On 2021/05/21 22:26, Fujii Masao wrote:
> 
> 
> On 2021/05/20 17:38, Masahiro Ikeda wrote:
>>
>>
>> On 2021/05/20 17:00, Fujii Masao wrote:
>>> On 2021/05/20 9:46, Masahiro Ikeda wrote:
>>>> On 2021/05/18 20:10, Fujii Masao wrote:
>>>>>>> pg_stat_database.tup_fetched:
>>>>>>> Number of index entries returned by scans on indexes in this database
>>>>>> Is this the sum of pg_stat_all_indexes.idx_tup_read? This is accounted to
>>>>>> pg_stat_database.tup_returned.
>>>>>
>>>>> I was thinking that pg_stat_database.tup_fetched is the same as
>>>>> the sum of pg_stat_all_tables.idx_tup_fetch. Because they both
>>>>> are incremented by bitmap index scans, but pg_stat_all_indexes.idx_tup_read
>>>>> is not.
>>>>
>>>> Yes. So, "Number of index entries returned by scans on indexes in this
>>>> database" is incorrect, and "Number of live rows fetched by index scans in
>>>> this database" is correct?
>>>
>>> Yes, I think so!
>>
>> Thanks!
>> I updated the patch for summarizing this thread.
> 
> Thanks for updating the patch! LGTM.
> 
> This is an improvement of documentation, so this should be applied in
> v15 dev cycle? If so, could you add the patch to the next CF? Or you think
> this is a bug fix and needs to be back-patched?

Thanks for checking the patch!
I thought this patch will be applied in V15 dev cycle.

OK. I added the patch to the next CF.
https://commitfest.postgresql.org/33/3130/

Regards,
-- 
Masahiro Ikeda
NTT DATA CORPORATION