Re: [PROPOSAL] VACUUM Progress Checker.

Hi Vinayak,

Thanks for updating the patch! A quick comment:

On 2016/02/26 17:28, pokurev(at)pm(dot)nttdata(dot)co(dot)jp wrote:
>> CREATE VIEW pg_stat_vacuum_progress AS
>> SELECT S.s[1] as pid,
>> S.s[2] as relid,
>> CASE S.s[3]
>> WHEN 1 THEN 'Scanning Heap'
>> WHEN 2 THEN 'Vacuuming Index and Heap'
>> ELSE 'Unknown phase'
>> END,
>> ....
>> FROM pg_stat_get_command_progress(PROGRESS_COMMAND_VACUUM) as S;
>>
>> # The name of the function could be other than *_command_progress.
> The name of function is updated as pg_stat_get_progress_info() and also updated the function.
> Updated the pg_stat_vacuum_progress view as suggested.

So, pg_stat_get_progress_info() now accepts a parameter to distinguish
different commands. I see the following in its definition:

+ /* Report values for only those backends which are running VACUUM
command */
+ if (cmdtype == COMMAND_LAZY_VACUUM)
+ {
+ /*Progress can only be viewed by role member.*/
+ if (has_privs_of_role(GetUserId(), beentry->st_userid))
+ {
+ values[2] = UInt32GetDatum(beentry->st_progress_param[0]);
+ values[3] = UInt32GetDatum(beentry->st_progress_param[1]);
+ values[4] = UInt32GetDatum(beentry->st_progress_param[2]);
+ values[5] = UInt32GetDatum(beentry->st_progress_param[3]);
+ values[6] = UInt32GetDatum(beentry->st_progress_param[4]);
+ values[7] = UInt32GetDatum(beentry->st_progress_param[5]);
+ if (beentry->st_progress_param[1] != 0)
+ values[8] = Float8GetDatum(beentry->st_progress_param[2] * 100 /
beentry->st_progress_param[1]);
+ else
+ nulls[8] = true;
+ }
+ else
+ {
+ nulls[2] = true;
+ nulls[3] = true;
+ nulls[4] = true;
+ nulls[5] = true;
+ nulls[6] = true;
+ nulls[7] = true;
+ nulls[8] = true;
+ }
+ }

How about doing this in a separate function which takes the command id as
parameter and returns an array of values and the number of values (per
command id). pg_stat_get_progress_info() then creates values[] and nulls[]
arrays from that and returns that as result set. It will be a cleaner
separation of activities, perhaps.

Thanks,
Amit