Re: Reduce TupleHashEntryData struct size by half - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Reduce TupleHashEntryData struct size by half
Date
Msg-id 202501141811.gxexpftdhtku@alvherre.pgsql
Whole thread Raw
In response to Re: Reduce TupleHashEntryData struct size by half  (David Rowley <dgrowleyml@gmail.com>)
List pgsql-hackers
On 2025-Jan-14, David Rowley wrote:

> The trick would be to ensure ExecClearTuple() still works. You
> obviously don't want to try and pfree() something that isn't a pointer
> to a palloc'd chunk. I'm not sure what the best API is, but I do see
> there are other places that might benefit from something that allows
> this.  The two usages of ExecCopySlotMinimalTuple() in nodeMemoize.c
> are candidates.

Maybe it would work to set a new flag in TupleTableSlot->tts_flag so
that ExecClearTuple() knows to handle it in some particular way (i.e.,
just skip the ->clear call altogether), with the idea that the tuple
memory belongs elsewhere and must not be freed by ExecClearTuple?

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"Los dioses no protegen a los insensatos.  Éstos reciben protección de
otros insensatos mejor dotados" (Luis Wu, Mundo Anillo)



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