Re: Add bms_offset_members() function for bitshifting Bitmapsets
David Rowley <dgrowleyml@gmail.com>
From: David Rowley <dgrowleyml@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Chao Li <li.evan.chao@gmail.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2026-04-18T07:49:57Z
Lists: pgsql-hackers
Attachments
- v2-0001-Introduce-bms_offset_members-function.patch (application/octet-stream) patch v2-0001
On Wed, 15 Apr 2026 at 14:33, David Rowley <dgrowleyml@gmail.com> 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. Patch attached for the version that creates a new set rather than modifying the input set in-place. David