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From: Andy Fan <zhihuifan1213@163.com>
To: Nikita Malakhov <hukutoc@gmail.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Michael Zhilin <m.zhilin@postgrespro.ru>
Cc: Peter Smith <smithpb2250@gmail.com>
Cc: vignesh C <vignesh21@gmail.com>
Cc: Matthias van de Meent <boekewurm+postgres@gmail.com>
Cc: pgsql-hackers@lists.postgresql.org
Subject: Re: Shared detoast Datum proposal
Date: Sun, 03 Mar 2024 09:52:16 +0800
Message-ID: <87msrgdq93.fsf@163.com> (raw)
In-Reply-To: <CAN-LCVON0vAr6tyiK4jsLmkCPd6PxkfxzXDyG8rjM9t3jOVM6g@mail.gmail.com>
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	<CAN-LCVON0vAr6tyiK4jsLmkCPd6PxkfxzXDyG8rjM9t3jOVM6g@mail.gmail.com>


Hi Nikita,

>
> Have you considered another one - to alter pg_detoast_datum
> (actually, it would be detoast_attr function) and save
> detoasted datums in the detoast context derived
> from the query context? 
>
> We have just enough information at this step to identify
> the datum - toast relation id and value id, and could
> keep links to these detoasted values in a, say, linked list
>  or hash table. Thus we would avoid altering the executor
> code and all detoast-related code would reside within
> the detoast source files?

I think you are talking about the way Tomas provided.  I am really
afraid that I was thought of too self-opinionated, but I do have some
concerns about this approch as I stated here [1], looks my concerns is
still not addressed, or the concerns itself are too absurd which is
really possible I think? 

[1] https://www.postgresql.org/message-id/875xyb1a6q.fsf%40163.com

-- 
Best Regards
Andy Fan






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