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Date: Wed, 15 Apr 2026 21:17:12 +0200
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Subject: Re: Add bms_offset_members() function for bitshifting Bitmapsets
To: David Rowley <dgrowleyml@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Chao Li <li.evan.chao@gmail.com>,
 PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
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From: Peter Eisentraut <peter@eisentraut.org>
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On 15.04.26 04:33, David Rowley wrote:
> On Wed, 15 Apr 2026 at 14:30, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>
>> David Rowley <dgrowleyml@gmail.com> writes:
>>> I'd not considered surprise-prone as an aspect. I understand we have
>>> bms_join and bms_union, which do the same thing if you only care about
>>> the value of the result and not what happens to the inputs.
>>
>> Sure, but bms_join is an optional optimization of the far safer
>> bms_union operation.  It bothers me to create the optimized case
>> but not the base case.
> 
> Hmm, yeah. That seems like a good argument for making a new set. I'll
> go make it so.

Depending on what you end up doing, maybe a sprinkling of pg_nodiscard 
could be appropriate.