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From: Ron Johnson <ronljohnsonjr@gmail.com>
Date: Mon, 24 Nov 2025 13:48:40 -0500
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 <CANzqJaAAmqHBe=hERcjbGQaTuiT3KX+d_eT-ed=-e1JeiT5snA@mail.gmail.com>
Subject: Re: Is the pg_isready database name relevant?
To: Pgsql-admin <pgsql-admin@lists.postgresql.org>
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On Mon, Nov 24, 2025 at 1:30=E2=80=AFPM Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Ron Johnson <ronljohnsonjr@gmail.com> writes:
> > This is something that *should* be fixed.
>
> What do you think a fix would consist of?  The program is working
> according to the design goals that were set for it.  In particular,
> the objective is to test whether the server is up --- and if it
> answers back with 'database "foo" does not exist', then yes it's
> up.


Remove the database option.


>   But at the same time, people might not wish to clutter their
> server log with failed-connection messages, so we provide the
> necessary options to make the test connection attempt a valid one.
>

Be thorough, or be really light.

These two do the exact same thing, but ncat can't generate a spurious log
entry:
pg_isready -h foo || handle error
ncat -zw10 foo 5432 || handle error

while this does a thorough check:
psql -h foo -d bar -U snaggle -qXc "\q" || handle error

And they all execute in the same amount of time.

--=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 Mon, Nov 24, 2025 at 1:30=E2=80=AFPM T=
om Lane &lt;<a href=3D"mailto:tgl@sss.pgh.pa.us">tgl@sss.pgh.pa.us</a>&gt; =
wrote:</div><div class=3D"gmail_quote gmail_quote_container"><blockquote cl=
ass=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid=
 rgb(204,204,204);padding-left:1ex">Ron Johnson &lt;<a href=3D"mailto:ronlj=
ohnsonjr@gmail.com" target=3D"_blank">ronljohnsonjr@gmail.com</a>&gt; write=
s:<br>
&gt; This is something that *should* be fixed.<br>
<br>
What do you think a fix would consist of?=C2=A0 The program is working<br>
according to the design goals that were set for it.=C2=A0 In particular,<br=
>
the objective is to test whether the server is up --- and if it<br>
answers back with &#39;database &quot;foo&quot; does not exist&#39;, then y=
es it&#39;s<br>
up.</blockquote><div><br></div><div>Remove the database option.</div><div>=
=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0=
.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">=C2=A0 But at=
 the same time, people might not wish to clutter their<br>
server log with failed-connection messages, so we provide the<br>
necessary options to make the test connection attempt a valid one.<br></blo=
ckquote><div><br></div><div>Be thorough, or be really light.</div><div><br>=
</div><div>These two do the exact same thing, but ncat can&#39;t generate a=
 spurious log entry:</div><div><font face=3D"monospace">pg_isready -h foo |=
| handle error</font></div><div><font face=3D"monospace">ncat -zw10 foo 543=
2</font><span style=3D"font-family:monospace">=C2=A0</span><span style=3D"f=
ont-family:monospace">|| handle error</span></div><div><br></div><div>while=
 this does a thorough=C2=A0check:</div><div><font face=3D"monospace">psql -=
h foo -d bar -U snaggle -qXc &quot;\q&quot;</font><span style=3D"font-famil=
y:monospace">=C2=A0</span><span style=3D"font-family:monospace">|| handle e=
rror</span></div><div><br></div><div>And they all execute in the same amoun=
t of time.</div><div><br></div></div><span class=3D"gmail_signature_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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