Re: [PATCH] Add extra statistics to explain for Nested Loop - Mailing list pgsql-hackers

From e.sokolova@postgrespro.ru
Subject Re: [PATCH] Add extra statistics to explain for Nested Loop
Date
Msg-id be95dbd55eae0974c89b56bc302bcb3a@postgrespro.ru
Whole thread Raw
In response to Re: [PATCH] Add extra statistics to explain for Nested Loop  (Justin Pryzby <pryzby@telsasoft.com>)
Responses Re: [PATCH] Add extra statistics to explain for Nested Loop  (vignesh C <vignesh21@gmail.com>)
Re: [PATCH] Add extra statistics to explain for Nested Loop  (Justin Pryzby <pryzby@telsasoft.com>)
List pgsql-hackers
Thank you for working on this issue. Your comments helped me make this 
patch more correct.

> Lines with "colon" format shouldn't use equal signs, and should use two 
> spaces
> between fields.
Done. Now extra line looks like "Loop min_rows: %.0f  max_rows: %.0f  
total_rows: %.0f" or "Loop min_time: %.3f  max_time: %.3f  min_rows: 
%.0f  max_rows: %.0f  total_rows: %.0f".

> Since this is now on a separate line, the "if (nloops > 1 && 
> es->verbose)"
> can be after the existing "if (es->timing)", and shouldn't need its own
> "if (es->timing)".  It should conditionally add a separate line, rather 
> than
> duplicating the "(actual.*" line.
> 
>> -            if (es->timing)
>> +            if (nloops > 1 && es->verbose)
New version of patch contains this correction. It helped make the patch 
shorter.

> In non-text mode, think you should not check "nloops > 1".  Rather, 
> print the
> field as 0.
The fields will not be zeros. New line will almost repeat the line with 
main sttistics.

> I think the labels in non-text format should say "Loop Min Time" or 
> similar.
> 
> And these variables should have a loop_ prefix like loop_min_t ?
There are good ideas. I changed it.

I apply new version of this patch. I hope it got better.
Please don't hesitate to share any thoughts on this topic.

-- 
Ekaterina Sokolova
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
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