| Lists: | pgsql-hackers |
|---|
| From: | Tatsuo Ishii <ishii(at)postgresql(dot)org> |
|---|---|
| To: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | TODO |
| Date: | 2012-08-21 03:16:11 |
| Message-ID: | 20120821.121611.501104647612634419.t-ishii@sraoss.co.jp |
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| Lists: | pgsql-hackers |
I found this in https://wiki.postgresql.org/wiki/Todo :
Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
What does this actually mean?
Add GUC switch to enable optimizer debug on/off?
More fancy/useful info should be printed?
If so, what kind of information is required?
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp
| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | Tatsuo Ishii <ishii(at)postgresql(dot)org> |
| Cc: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: TODO |
| Date: | 2012-08-23 19:21:25 |
| Message-ID: | 20120823192125.GC5971@momjian.us |
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| Lists: | pgsql-hackers |
On Tue, Aug 21, 2012 at 12:16:11PM +0900, Tatsuo Ishii wrote:
> I found this in https://wiki.postgresql.org/wiki/Todo :
>
> Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
>
> What does this actually mean?
>
> Add GUC switch to enable optimizer debug on/off?
> More fancy/useful info should be printed?
> If so, what kind of information is required?
Well, right now, OPTIMIZER_DEBUG lets you see what plans were considered
and removed. I was thinking that information should be available
without a special compiled binary.
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
| From: | Josh Berkus <josh(at)agliodbs(dot)com> |
|---|---|
| To: | pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: TODO |
| Date: | 2012-08-23 23:08:38 |
| Message-ID: | 5036B7F6.1070504@agliodbs.com |
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| Lists: | pgsql-hackers |
> Well, right now, OPTIMIZER_DEBUG lets you see what plans were considered
> and removed. I was thinking that information should be available
> without a special compiled binary.
+1. It would also be popular with our academic users.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com
| From: | Peter Geoghegan <peter(at)2ndquadrant(dot)com> |
|---|---|
| To: | Bruce Momjian <bruce(at)momjian(dot)us> |
| Cc: | Tatsuo Ishii <ishii(at)postgresql(dot)org>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: TODO |
| Date: | 2012-08-24 00:30:13 |
| Message-ID: | CAEYLb_U-0bwfZJSyzDqx5hkE+PrE=a6pSPi9MA605qa3jRwhnQ@mail.gmail.com |
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| Lists: | pgsql-hackers |
On 23 August 2012 20:21, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> On Tue, Aug 21, 2012 at 12:16:11PM +0900, Tatsuo Ishii wrote:
>> I found this in https://wiki.postgresql.org/wiki/Todo :
>>
>> Improve ability to display optimizer analysis using OPTIMIZER_DEBUG
>>
>> What does this actually mean?
>>
>> Add GUC switch to enable optimizer debug on/off?
>> More fancy/useful info should be printed?
>> If so, what kind of information is required?
>
> Well, right now, OPTIMIZER_DEBUG lets you see what plans were considered
> and removed. I was thinking that information should be available
> without a special compiled binary.
That seems like an unreasonable burden on what OPTIMIZER_DEBUG can do.
If you can't build Postgres from source, something that is relatively
low barrier, you have little hope of sensibly interpreting low-level
output from the planner. However, I could get behind having it as a
configure option, which it is currently not. It would probably also
make sense to expose SELECTIVITY_DEBUG and GEQO_DEBUG.
--
Peter Geoghegan http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training and Services