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Date: Wed, 31 Jul 2024 05:47:40 -0400
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Subject: Re: can we mark upper/lower/textlike functions leakproof?
To: David Rowley <dgrowleyml@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
References: <fa7903f6-b050-4c62-aa52-6f6d5d345770@dunslane.net>
 <CAApHDvr36T+9XZYTRkHkGm82Wo5YY6wXwkRDceu2-cyGEvHzjw@mail.gmail.com>
From: Andrew Dunstan <andrew@dunslane.net>
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On 2024-07-30 Tu 6:51 PM, David Rowley wrote:
> On Wed, 31 Jul 2024 at 09:35, Andrew Dunstan<andrew@dunslane.net>  wrote:
>> Fast forward to now. The customer has found no observable ill effects of
>> marking these functions leakproof. The would like to know if there is
>> any reason why we can't mark them leakproof, so that they don't have to
>> do this in every database of every cluster they use.
>>
>> Thoughts?
> According to [1], it's just not been done yet due to concerns about
> risk to reward ratios.  Nobody mentioned any reason why it couldn't
> be, but there were some fears that future code changes could yield new
> failure paths.
>
> David
>
> [1]https://postgr.es/m/02BDFCCF-BDBB-4658-9717-4D95F9A91561%40thebuild.com


Hmm, somehow I missed that thread in searching, and clearly I'd 
forgotten it.

Still, I'm not terribly convinced by arguments along the lines you're 
suggesting. "Sufficient unto the day is the evil thereof." Maybe we need 
a test to make sure we don't make changes along those lines, although I 
have no idea what such a test would look like.


cheers

andrew

--
Andrew Dunstan
EDB:https://www.enterprisedb.com

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    <p><br>
    </p>
    <div class="moz-cite-prefix">On 2024-07-30 Tu 6:51 PM, David Rowley
      wrote:<br>
    </div>
    <blockquote type="cite"
cite="mid:CAApHDvr36T+9XZYTRkHkGm82Wo5YY6wXwkRDceu2-cyGEvHzjw@mail.gmail.com">
      <pre class="moz-quote-pre" wrap="">On Wed, 31 Jul 2024 at 09:35, Andrew Dunstan <a class="moz-txt-link-rfc2396E" href="mailto:andrew@dunslane.net">&lt;andrew@dunslane.net&gt;</a> wrote:
</pre>
      <blockquote type="cite">
        <pre class="moz-quote-pre" wrap="">Fast forward to now. The customer has found no observable ill effects of
marking these functions leakproof. The would like to know if there is
any reason why we can't mark them leakproof, so that they don't have to
do this in every database of every cluster they use.

Thoughts?
</pre>
      </blockquote>
      <pre class="moz-quote-pre" wrap="">
According to [1], it's just not been done yet due to concerns about
risk to reward ratios.  Nobody mentioned any reason why it couldn't
be, but there were some fears that future code changes could yield new
failure paths.

David

[1] <a class="moz-txt-link-freetext" href="https://postgr.es/m/02BDFCCF-BDBB-4658-9717-4D95F9A91561%40thebuild.com">https://postgr.es/m/02BDFCCF-BDBB-4658-9717-4D95F9A91561%40thebuild.com</a></pre>
    </blockquote>
    <p><br>
    </p>
    <p>Hmm, somehow I missed that thread in searching, and clearly I'd
      forgotten it.</p>
    <p>Still, I'm not terribly convinced by arguments along the lines
      you're suggesting. "Sufficient unto the day is the evil thereof."
      Maybe we need a test to make sure we don't make changes along
      those lines, although I have no idea what such a test would look
      like.<br>
    </p>
    <p><br>
    </p>
    <p><span style="white-space: pre-wrap">cheers</span></p>
    <p><span style="white-space: pre-wrap">
</span></p>
    <p><span style="white-space: pre-wrap">andrew
</span></p>
    <pre class="moz-signature"
    signature-switch-id="d0437855-2267-4610-80b3-83167ec45b0b" cols="72">--
Andrew Dunstan
EDB: <a class="moz-txt-link-freetext" href="https://www.enterprisedb.com">https://www.enterprisedb.com</a>
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