Re: [PATCH] Covering SPGiST index

From: Pavel Borisov <pashkin(dot)elfe(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: David Steele <david(at)pgmasters(dot)net>, "Andrey M(dot) Borodin" <x4mmm(at)yandex-team(dot)ru>, Anastasia Lubennikova <a(dot)lubennikova(at)postgrespro(dot)ru>, Postgres hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: [PATCH] Covering SPGiST index
Date: 2021-03-25 19:47:29
Message-ID: CALT9ZEGcY2WZFdKNphekYmCSGryJRKn5=MJW09_s+e7iz7w09w@mail.gmail.com
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>
> On further contemplation, it occurs to me that if we make the switch
> to "key values are stored per normal rules", then even if there is an
> index with pass-by-value keys out there someplace, it would only break
> on big-endian architectures. On little-endian, the extra space
> occupied by the Datum format would just seem to be padding space.
> So this probably means that the theoretical compatibility hazard is
> small enough to be negligible, and we should go with my option #2
> (i.e., we need to replace SGLTDATUM with normal attribute-fetch logic).
>
> regards, tom lane
>

I am sorry for the delay in reply. Now I've returned to the work on the
patch.
First of all big thanks for good pieces of advice. I especially liked the
idea of not allocating a big array in a picksplit procedure and doing
deform and form tuples on the fly.
I found all notes mentioned are quite worth integrating into the patch, and
have made the next version of a patch (with a pgindent done also). PFA v 14.

I hope I understand the way to modify SGLTDATUM in the right way. If not
please let me know. (The macro SGLTDATUM itself is not removed, it calls
fetch_att. And I find this suitable as the address for the first tuple
attribute is MAXALIGNed).

Thanks again for your consideration. From now I hope to be able to work on
the feature with not so big delay.

--
Best regards,
Pavel Borisov

Postgres Professional: http://postgrespro.com <http://www.postgrespro.com>

Attachment Content-Type Size
v14-0001-Covering-SP-GiST-index-support-for-INCLUDE-colum.patch application/octet-stream 60.0 KB

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