Date: Wed, 13 Aug 2025 03:55:41 +0000
From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
To: Jeff Davis <pgsql@j-davis.com>
Cc: Michael Paquier <michael@paquier.xyz>,
	Greg Sabino Mullane <htamfids@gmail.com>,
	pgsql-hackers@lists.postgresql.org
Subject: Re: Adding locks statistics
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Hi,

On Tue, Aug 12, 2025 at 08:42:48AM -0700, Jeff Davis wrote:
> On Tue, 2025-08-12 at 09:37 +0000, Bertrand Drouvot wrote:
> > It can be used for example for:
> > 
> > 1. checking if "waits" is close to "requests". Then it means you
> > usually have to
> > wait before acquiring the lock, which means you may have a
> > concurrency issue.
> > 
> > 2. lock_timeout and deadlock_timeout tuning (lock_timeout is visible
> > only in the
> > logs if log_min_error_statement is set appropriately).
> > 
> > 3. checking the "requests"/"fastpath" ratio to see if
> > "max_locks_per_transaction"
> > needs tuning (see c4d5cb71d2).
> > "
> > 
> > Do these seem like useful use cases?
> 
> Those seem plausibly useful,

Thanks for sharing your thoughts about the use cases above.

> and I wanted to hear more from others.

> For instance, a view could be helpful to diagnose concurrency issues,
> but I think that's worth discussing in more detail to see what kinds of
> issues it can help with and how it complements other approaches. I
> suspect when we get into the details, different people (or different
> situations) would want slightly different information out of that view.

Fully agree, getting input from others definitely helps validate the approach
and see if the current design needs some changes.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com