Re: [HACKERS] CLUSTER command progress monitor

Hi Alvaro!

>>>> Is this fix strictly necessary for pg12, or is this something that we
>>>> can leave for pg13?
>>>
>>> Not only me but many DBA needs this progress report feature on PG12,
>>> therefore I'm trying to fix the problem. If you send other patch to
>>> fix the problem, and it is more elegant than mine, I can withdraw my patch.
>>> Anyway, I want to avoid this feature being reverted.
>>> Do you have any ideas to fix the problem?
>>
>> I committed a fix for the originally reported problem as da47e43dc32e in
>> branch REL_12_STABLE.  Is that insufficient, and if so why?
>
>
> Ooops, I misunderstood. I now realized you committed your patch to
> fix the problem. Thanks! I'll test it later. :)
>
> https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=da47e43dc32e3c5916396f0cbcfa974b371e4875

I tested your patch (da47e43d) and it works fine. Thanks! :)
So, my patch improving progress reporting API can leave for PG13.

#Test scenario
===================
[Session #1]
select * from pg_stat_progress_cluster ; \watch 0.0001

[Session #2]
create table hoge as select a from generate_series(1, 100000) a;
create index ind_hoge1 on hoge(a);
create index ind_hoge2 on hoge((a%2));
create index ind_hoge3 on hoge((a%3));
create index ind_hoge4 on hoge((a%4));
create index ind_hoge5 on hoge((a%5));
cluster hoge using ind_hoge1;
===================

#Test result
===================
22283|13593|postgres|16384|CLUSTER|initializing|0|0|0|0|0|0
...
22283|13593|postgres|16384|CLUSTER|rebuilding index|16387|100000|100000|0|0|0 <= Increasing from 0 to 5
22283|13593|postgres|16384|CLUSTER|rebuilding index|16387|100000|100000|0|0|1
22283|13593|postgres|16384|CLUSTER|rebuilding index|16387|100000|100000|0|0|2
22283|13593|postgres|16384|CLUSTER|rebuilding index|16387|100000|100000|0|0|3
22283|13593|postgres|16384|CLUSTER|rebuilding index|16387|100000|100000|0|0|4
22283|13593|postgres|16384|CLUSTER|performing final cleanup|16387|100000|100000|0|0|5
===================

Thanks,
Tatsuro Yamada