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From: "David G. Johnston" <david.g.johnston@gmail.com>
Date: Wed, 16 Feb 2022 23:51:02 -0700
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 <CAKFQuwYXFimG=bBeR9DSWVKK8at_+s_eBbcXDtMuyP38xa0R7Q@mail.gmail.com>
Subject: Re: range data type size not mention in docs.
To: Jian He <hejian.mark@gmail.com>
Cc: "pgsql-docs@lists.postgresql.org" <pgsql-docs@lists.postgresql.org>
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On Wednesday, February 16, 2022, Jian He <hejian.mark@gmail.com> wrote:

>
> range type seem not mention their size in the docs.
> multi range size is variable.
> But range size seems fixed.
> why it's 17 byte?
>
> select  pg_column_size('[10,20)' ::int4range ); --17 byte
> select  pg_column_size('[-2147483648,2147483647)' ::int4range ); --17 byte.
>
> https://github.com/postgres/postgres/blob/4429f6a9e3e12bb4af6e3677fbc78cd80f160252/src/backend/utils/adt/rangetypes.c#L183

* Binary representation: The first byte is the flags, then 4 bytes are the
 * range type Oid, then the lower bound (if present) then the upper bound (if
 * present). Each bound is represented by a 4-byte length header and the binary
 * representation of that bound (as returned by a call to the send function for
 * the subtype).

David J.

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On Wednesday, February 16, 2022, Jian He &lt;<a href=3D"mailto:hejian.mark@=
gmail.com">hejian.mark@gmail.com</a>&gt; wrote:<br><blockquote class=3D"gma=
il_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-lef=
t:1ex"><div dir=3D"ltr"><div><br></div><div>range type seem not mention the=
ir size in the docs.</div><div>multi range size is variable. <br></div><div=
>But range size seems fixed.</div><div>why it&#39;s 17 byte? <br></div><div=
><pre style=3D"background-color:rgb(30,30,30);color:rgb(212,212,212);font-f=
amily:&quot;JetBrains Mono&quot;,monospace;font-size:9.8pt"><span style=3D"=
color:rgb(73,156,213)">select  </span><span style=3D"color:rgb(220,220,170)=
">pg_column_size</span>(<span style=3D"color:rgb(205,144,105)">&#39;[10,20)=
&#39; </span>::<span style=3D"color:rgb(211,211,200)">int4range </span>); <=
span style=3D"color:rgb(105,152,86)">--17 byte<br></span><span style=3D"col=
or:rgb(73,156,213)">select  </span><span style=3D"color:rgb(220,220,170)">p=
g_column_size</span>(<span style=3D"color:rgb(205,144,105)">&#39;[-21474836=
48,<wbr>2147483647)&#39; </span>::<span style=3D"color:rgb(211,211,200)">in=
t4range </span>); <span style=3D"color:rgb(105,152,86)">--17 byte.</span></=
pre></div></div></blockquote><div><pre style=3D"word-wrap:break-word"><a hr=
ef=3D"https://github.com/postgres/postgres/blob/4429f6a9e3e12bb4af6e3677fbc=
78cd80f160252/src/backend/utils/adt/rangetypes.c#L183" style=3D"font-family=
:&quot;Helvetica Neue&quot;,Helvetica,Arial,sans-serif">https://github.com/=
postgres/postgres/blob/4429f6a9e3e12bb4af6e3677fbc78cd80f160252/src/backend=
/utils/adt/rangetypes.c#L183</a>=C2=A0</pre><pre style=3D"word-wrap:break-w=
ord">* Binary representation: The first byte is the flags, then 4 bytes are=
 the
 * range type Oid, then the lower bound (if present) then the upper bound (=
if
 * present). Each bound is represented by a 4-byte length header and the bi=
nary
 * representation of that bound (as returned by a call to the send function=
 for
 * the subtype).</pre><pre style=3D"word-wrap:break-word">David J.</pre><pr=
e style=3D"word-wrap:break-word"><br></pre></div>

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