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From: Ranier Vilela <ranier.vf@gmail.com>
Date: Mon, 9 Mar 2026 11:05:09 -0300
Message-ID: 
 <CAEudQApEfvhNT1fEPURzVcQH7G0A1ukh_ugoCGaErV6_dbndCQ@mail.gmail.com>
Subject: Re: Avoid multiple calls to memcpy (src/backend/access/index/genam.c)
To: Pg Hackers <pgsql-hackers@postgresql.org>
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Em seg., 9 de mar. de 2026 =C3=A0s 10:16, Ranier Vilela <ranier.vf@gmail.co=
m>
escreveu:

> Hi.
>
> In the functions *systable_beginscan* and *systable_beginscan_ordered*,
> is possible a small optimization.
> The array *idxkey* can be constructed in one go with a single call to
> mempcy.
> The excess might not make much of a difference, but I think it's worth th=
e
> effort.
>
> patch attached.
>
Someone asked me if O2 does not do the work.
Apparently not.

https://godbolt.org/z/h5dndz33x

best regards,
Ranier Vilela

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<div dir=3D"ltr"><br><div class=3D"gmail_quote gmail_quote_container"><div =
dir=3D"ltr" class=3D"gmail_attr">Em seg., 9 de mar. de 2026 =C3=A0s 10:16, =
Ranier Vilela &lt;<a href=3D"mailto:ranier.vf@gmail.com">ranier.vf@gmail.co=
m</a>&gt; escreveu:<br></div><blockquote class=3D"gmail_quote" style=3D"mar=
gin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1=
ex"><div dir=3D"ltr"><div>Hi.</div><div><br></div><div>In the functions *sy=
stable_beginscan* and *systable_beginscan_ordered*,</div><div>is possible a=
 small optimization.</div><div>The array *idxkey* can be constructed in one=
 go with a single call to mempcy.</div><div>The excess might not make much =
of a difference, but I think it&#39;s worth the effort.</div><div><br></div=
><div>patch attached.</div></div></blockquote><div>Someone asked me if O2 d=
oes not do the work.</div><div>Apparently not.</div><div><br></div><div><a =
href=3D"https://godbolt.org/z/h5dndz33x">https://godbolt.org/z/h5dndz33x</a=
></div><div><br></div><div>best regards,</div><div>Ranier Vilela</div></div=
></div>

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