Re: Expanding HOT updates for expression and partial indexes

On Tue, Mar 24, 2026 at 02:02:07PM -0400, Greg Burd wrote:
> On Mon, Mar 23, 2026, at 2:39 PM, Nathan Bossart wrote:
>> On Tue, Mar 17, 2026 at 02:04:11PM -0400, Greg Burd wrote:
>>> - * INDEX_ATTR_BITMAP_SUMMARIZED Columns included in summarizing indexes
>>> + * INDEX_ATTR_BITMAP_INDEXED Columns referenced by indexes
>>> + * INDEX_ATTR_BITMAP_SUMMARIZED Columns only included in summarizing indexes
>>
>>> - Bitmapset *summarizedattrs; /* columns with summarizing indexes */
>>> + Bitmapset *indexedattrs; /* columns referenced by indexes */
>>> + Bitmapset *summarizedattrs; /* columns only in summarizing indexes */
>>
>> As before, the comment changes for the summarized-attr-related stuff seem
>> unnecessary.
>
> I disagree, the "only" is required to highlight the logic change here.
> Before this patch summarized attrs could overlap with indexed attrs, now
> it should not. This makes the logic a bit easier later in
> HeapUpdateHotAllowable().

My bad, you are right.

> So, we go from 3 calls to RelationGetIndexAttrBitmap() to 1, or at most 2
> when there's a summarizing index (which is frequently the case).
>
> This feels more logical, cleaner, and has less overhead but supports the
> same HOT logic.

Nice.

--
nathan