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From: Ron Johnson <ronljohnsonjr@gmail.com>
Date: Wed, 10 Sep 2025 20:11:15 -0400
Message-ID: <CANzqJaD2jy5tQ4XBUDE-NUrn1DjbACOovB9hdybBCQH6=+aDOg@mail.gmail.com>
Subject: Re: MVCC and all that...
To: pgsql-general <pgsql-general@postgresql.org>
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On Wed, Sep 10, 2025 at 6:20=E2=80=AFPM Justin <zzzzz.graf@gmail.com> wrote=
:

> On Wed, Sep 10, 2025 at 5:28=E2=80=AFPM Nico Williams <nico@cryptonector.=
com>
> wrote:
>
>>  [snip]

> I would really like out-of-band hints.  These would be hints not
>> specified in the SQL itself but to be sent separately and which address
>> table sources or joins by name, like this:
>>
>> psql> SELECT .. FROM x x1 JOIN y y1 ON .. JOIN y y2 ON .. WHERE ..;
>> ...> \hint y1 indexed by ..
>> ...> \hint y2 indexed by ..
>> ...> ;
>>
>
> I humbly disagree, the point of SQL being a 4th  generation language is,
> I tell it what I want, not how to go get what I want.
>

And the point of high-level languages is to eliminate GOTO, and yet GOTO
still exists.

The real problem is requiring the application to carry the hints.

My old RDBMS let you CREATE HINT to which you (the DBA) would put a SELECT,
UPDATE or DELETE statement (similar to PREPARE), and what indices to use.
That way, the application doesn't carry them, and "you" can update them as
needed.

Rarely useful, but occasionally *VERY* useful.

--=20
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> lobster!

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<div dir=3D"ltr"><div dir=3D"ltr">On Wed, Sep 10, 2025 at 6:20=E2=80=AFPM J=
ustin &lt;<a href=3D"mailto:zzzzz.graf@gmail.com">zzzzz.graf@gmail.com</a>&=
gt; wrote:</div><div class=3D"gmail_quote gmail_quote_container"><blockquot=
e class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px s=
olid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div>On Wed, Sep 1=
0, 2025 at 5:28=E2=80=AFPM Nico Williams &lt;<a href=3D"mailto:nico@crypton=
ector.com" target=3D"_blank">nico@cryptonector.com</a>&gt; wrote:</div><div=
 class=3D"gmail_quote"><blockquote class=3D"gmail_quote" style=3D"margin:0p=
x 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"></=
blockquote></div></div></blockquote><div>=C2=A0[snip]</div><blockquote clas=
s=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid r=
gb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div class=3D"gmail_quot=
e"><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;bord=
er-left:1px solid rgb(204,204,204);padding-left:1ex">
I would really like out-of-band hints.=C2=A0 These would be hints not<br>
specified in the SQL itself but to be sent separately and which address<br>
table sources or joins by name, like this:<br>
<br>
psql&gt; SELECT .. FROM x x1 JOIN y y1 ON .. JOIN y y2 ON .. WHERE ..;<br>
...&gt; \hint y1 indexed by ..<br>
...&gt; \hint y2 indexed by ..<br>
...&gt; ;<br></blockquote><div><br>I humbly disagree, the point of SQL bein=
g=C2=A0a 4th=C2=A0 generation language is,=C2=A0 I tell it what I want, not=
 how to go get=C2=A0what I want.=C2=A0</div></div></div></blockquote><div>=
=C2=A0</div></div><div>And the point of high-level languages is to eliminat=
e GOTO, and yet GOTO still exists.</div><div><br></div><div>The real proble=
m is requiring the application to carry the hints.</div><div><br></div><div=
>My old RDBMS let you CREATE HINT to which you (the DBA) would put a SELECT=
, UPDATE or DELETE statement (similar to PREPARE), and what indices to use.=
=C2=A0 That way, the application doesn&#39;t carry them, and &quot;you&quot=
; can update them as needed.</div><div><br></div><div>Rarely useful, but oc=
casionally *VERY* useful.</div><div><br></div><span class=3D"gmail_signatur=
e_prefix">-- </span><br><div dir=3D"ltr" class=3D"gmail_signature"><div dir=
=3D"ltr">Death to &lt;Redacted&gt;, and butter sauce.<div>Don&#39;t boil me=
, I&#39;m still alive.<br><div><div>&lt;Redacted&gt; lobster!</div></div></=
div></div></div></div>

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