[pgpool-hackers: 4474] Re: [PATCH] printing empty row first in query "show pool_process"

[Tatsuo Ishii]

Hello Kwangwon Seo,

> Hello, I want to fix a minor thing, which is might not a critical thing.
> 
> kashif_zeeshan([kashif.z at bitnine.net](https://www.pgpool.net/mailman/listinfo/pgpool-hackers)) also shared this to me, and I had the same thing.
> 
> -- reporting (cutoff)
> 
> The problem is "show processes" query showing empty row result first.
[snip]
> -- analysis
> 
> In short, because of send_row_description calling twice, psql like client showing emptry row result first before actual contents, that are, process informations.

> by the way, V4_1 is fine because calling send_row_description() then sending DataRow.

I have pushed your patch down to V4.2. Thank you!

> -- additional reporting.
> 
> The one thing confusing my decision is thepg14 does not print empty row first so totally looks fine like this.
> 
> postgres at master:/tmp$ psql -h localhost -p 11000 -c "show pool_processes;"
> 
> pool_pid | start_time
> 
> ----------+---------------------
> 
> 56 | 2024-06-12 09:58:08
> 
> 58 | 2024-06-12 09:58:08
> 
> 59 | 2024-06-12 09:58:08
> 
> (3 rows)
> 
> ( tested with pool: 4.4.6 (nurikoboshi), pg: PostgreSQL 14.12 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0, 64-bit )

Yeah. My guess is libpq or psql were changed in v15.

> -- suggestion
> 
> Even if it looks like fine, I think that we should following FE/BE protocol properly.
> 
> Oh. This is my suggestion, and you can suggest or tell me whatever you want.

I think you are absolutely correct.

> anyway, Could you please review my opinion?

Your patches look fine to me.

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp