Thread

Re: Row pattern recognition

Tatsuo Ishii <ishii@postgresql.org> — 2026-05-31T00:11:19Z

Hi Henson, Jian,

>> In src/include/nodes/execnodes.h, we're adding quite a few fields to
>> WindowAggState that are only used for RPR queries.
>> Should we consolidate these fields behind a single pointer (named
>> RPRContext) to keep the WindowAggState size smaller for non-RPR
>> queries?
> 
> The size win is real -- it's roughly 450-500 bytes per WindowAggState
> that every non-RPR window query carries today. But it takes a wide
> code change to get there: it reshapes every RPR access path, a
> sizable (if mostly mechanical) diff across nodeWindowAgg.c,
> execRPR.c, and the explain side.
> 
> Tatsuo, as co-author -- do you want this in v48? If you do, I'll
> prepare the RPRContext consolidation as an incremental patch for you to
> fold into v48. It isn't blocking either way.

Basically I think Jian's idea is good. In addition to the size reason
above, we would have less code changes when we adapt existing R020
codes to R010.

However it will need a wide code change as Henson said. I would like
to focus on stabilizing our code for now. Therefore I would not want
the refactoring in v48.

Regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp