Re: Feature improvement for pg_stat_statements

On 2020/11/27 21:39, Seino Yuki wrote:
> 2020-11-27 21:37 に Seino Yuki さんは書きました:
>> 2020-11-16 12:28 に Seino Yuki さんは書きました:
>>> Due to similar fixed, we have also merged the patches discussed in the
>>> following thread.
>>> https://commitfest.postgresql.org/30/2736/
>>> The patch is posted on the 2736 side of the thread.
>>>
>>> Regards.
>>
> 
> I forgot the attachment and will resend it.
> 
> The following patches have been committed and we have created a
> compliant patch for them.
> https://commitfest.postgresql.org/30/2736/
> 
> Please confirm.

Thanks for updating the patch! Here are review comments from me.

+    OUT reset_exec_time TIMESTAMP WITH TIME ZONE

I prefer "stats_reset" as the name of this column for the sake of
consistency with the similar column in other stats views like
pg_stat_database.

Isn't it better to use lower cases for "TIMESTAMP WITH TIME ZONE"
because other DDLs in pg_stat_statements do that for the declaraion
of data type?

@@ -565,6 +568,8 @@ pgss_shmem_startup(void)
          pgss->n_writers = 0;
          pgss->gc_count = 0;
          pgss->stats.dealloc = 0;
+        pgss->stats.reset_exec_time = 0;
+        pgss->stats.reset_exec_time_isnull = true;

The reset time should be initialized with GetCurrentTimestamp() instead
of 0? If so, I think that we can completely get rid of reset_exec_time_isnull.

+    memset(nulls, 0, sizeof(nulls));

If some entries in "values[]" may not be set, "values[]" also needs to
be initialized with 0.

MemSet() should be used, instead?

+    /* Read dealloc */
+    values[0] = stats.dealloc;

Int64GetDatum() should be used here?

+    reset_ts = GetCurrentTimestamp();

GetCurrentTimestamp() needs to be called only when all the entries
are removed. But it's called even in other cases.

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION