Date: Wed, 22 Aug 2018 20:58:45 +0200 (CEST)
From: Andreas Joseph Krogh <andreas@visena.com>
To: Andres Freund <andres@anarazel.de>
Cc: Robert Haas <robertmhaas@gmail.com>,
	Alvaro Herrera <alvherre@2ndquadrant.com>,
	"Jonathan S. Katz" <jkatz@postgresql.org>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Message-ID: <VisenaEmail.31.c08fca6668dabfb5.165630040a6@tc7-visena>
In-Reply-To: <20180822185205.dtfe722isnkdlfgg@alap3.anarazel.de>
Subject: Re: Query is over 2x slower with jit=on
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P=C3=A5 onsdag 22. august 2018 kl. 20:52:05, skrev Andres Freund <andres@an=
arazel.de=20
<mailto:andres@anarazel.de>>:
On 2018-08-22 19:51:12 +0200, Andreas Joseph Krogh wrote:
 > I thought=C2=A0JITing of prepared=C2=A0queries happended once (in "prepa=
re")

 No, it happens when the first JITed function is executed.


 > =C2=A0so it didn't have to do the JITing every time the query is
 > executed. Isn't the=C2=A0previously generated bytecode usable for
 > subsequent queries?

 No, not currently. There's some reasons preventing that (primarily that
 we currently rely on addresses of certain things not to change during
 execution). There's ongoing work to change that, but that's certainly
 not going to be ready for v11.

 Greetings,

 Andres Freund
=C2=A0
=C2=A0
Ok, thanks for clarifying.
=C2=A0
--
 Andreas Joseph Krogh


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<div>P=C3=A5 onsdag 22. august 2018 kl. 20:52:05, skrev Andres Freund &lt;<=
a href=3D"mailto:andres@anarazel.de">andres@anarazel.de</a>&gt;:</div>

<blockquote style=3D"border-left: 1px solid rgb(204, 204, 204); margin: 0pt=
 0pt 0pt 0.8ex; padding-left: 1ex;">
<div style=3D"display:inline; font-family: monospace; font-size: 12px;">On =
2018-08-22 19:51:12 +0200, Andreas Joseph Krogh wrote:<br>
&gt; I thought=C2=A0JITing of prepared=C2=A0queries happended once (in &quo=
t;prepare&quot;)<br>
<br>
No, it happens when the first JITed function is executed.<br>
<br>
<br>
&gt; =C2=A0so it didn't have to do the JITing every time the query is<br>
&gt; executed. Isn't the=C2=A0previously generated bytecode usable for<br>
&gt; subsequent queries?<br>
<br>
No, not currently. There's some reasons preventing that (primarily that<br>
we currently rely on addresses of certain things not to change during<br>
execution). There's ongoing work to change that, but that's certainly<br>
not going to be ready for v11.<br>
<br>
Greetings,<br>
<br>
Andres Freund</div>
</blockquote>

<div>=C2=A0</div>

<div>=C2=A0</div>

<div>Ok, thanks for clarifying.</div>

<div>=C2=A0</div>

<div class=3D"visena-email-signature" data-visena-message-id=3D"&lt;VisenaE=
mail.31.c08fca6668dabfb5.165630040a6@tc7-visena>">
<div>--<br>
Andreas Joseph Krogh</div>
</div>
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