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From: Pavel Stehule <pavel.stehule@gmail.com>
Date: Sun, 29 Dec 2024 07:24:55 +0100
Message-ID: 
 <CAFj8pRD+Y=ZFM+xYpx4kt395h8moR9g-nVbGMMKy7eayXXNw2g@mail.gmail.com>
Subject: Re: Re: proposal: schema variables
To: jian he <jian.universality@gmail.com>
Cc: Dmitry Dolgov <9erthalion6@gmail.com>,
 Laurenz Albe <laurenz.albe@cybertec.at>,
	Erik Rijkers <er@xs4all.nl>, Michael Paquier <michael@paquier.xyz>,
	Amit Kapila <amit.kapila16@gmail.com>, DUVAL REMI <REMI.DUVAL@cheops.fr>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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Hi


>> + {
>> + /* the last field of list can be star too */
>> + Assert(IsA(field2, A_Star));
>> +
>> + /*
>> + * In this case, the field1 should be variable name. But
>> + * direct unboxing of composite session variables is not
>> + * supported now, and then we don't need to try lookup
>> + * related variable.
>> + *
>> + * Unboxing is supported by syntax (var).*
>> + */
>> + return InvalidOid;
>> + }
>> I don't fully understand the above comments,
>>
>
> The parser allows only two syntaxes - identifier.identifier or
> identifier.star. Second
> syntax is not supported by session variables, and then I didn't try to
> search for the variable.
> Some users can be confused by similar syntaxes identifier.* and
> (identifier).* Only
> second syntax is composite unboxing, and only second syntax is supported
> for
> session variables.
>
>
I changed this comment to

<--><--><--><--><-->/*
<--><--><--><--><--> * The syntax ident.* is used only by table aliases,
<--><--><--><--><--> * and then this identifier cannot be a reference to
<--><--><--><--><--> * session variable.
<--><--><--><--><--> */

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Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div>Hi<br></div><div dir=3D"ltr"><br></div><div class=3D"=
gmail_quote gmail_quote_container"><blockquote class=3D"gmail_quote" style=
=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding=
-left:1ex"><div dir=3D"ltr"><div class=3D"gmail_quote"><blockquote class=3D=
"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(2=
04,204,204);padding-left:1ex"><br>
+ {<br>
+ /* the last field of list can be star too */<br>
+ Assert(IsA(field2, A_Star));<br>
+<br>
+ /*<br>
+ * In this case, the field1 should be variable name. But<br>
+ * direct unboxing of composite session variables is not<br>
+ * supported now, and then we don&#39;t need to try lookup<br>
+ * related variable.<br>
+ *<br>
+ * Unboxing is supported by syntax (var).*<br>
+ */<br>
+ return InvalidOid;<br>
+ }<br>
I don&#39;t fully understand the above comments,<br></blockquote><div><br><=
/div><div>The parser allows only two syntaxes - identifier.identifier or id=
entifier.star. Second</div><div>syntax is not supported by session variable=
s, and then I didn&#39;t try to search for the variable.</div><div>Some use=
rs can be confused by similar syntaxes identifier.* and (identifier).* Only=
</div><div>second syntax is composite unboxing, and only second syntax is s=
upported for</div><div>session variables.</div><br></div></div></blockquote=
><div><br></div><div>I changed this comment to</div><div><br></div><div>&lt=
;--&gt;&lt;--&gt;&lt;--&gt;&lt;--&gt;&lt;--&gt;/*<br>&lt;--&gt;&lt;--&gt;&l=
t;--&gt;&lt;--&gt;&lt;--&gt; * The syntax ident.* is used only by table ali=
ases,<br>&lt;--&gt;&lt;--&gt;&lt;--&gt;&lt;--&gt;&lt;--&gt; * and then this=
 identifier cannot be a reference to<br>&lt;--&gt;&lt;--&gt;&lt;--&gt;&lt;-=
-&gt;&lt;--&gt; * session variable.<br>&lt;--&gt;&lt;--&gt;&lt;--&gt;&lt;--=
&gt;&lt;--&gt; */<br>=C2=A0</div></div></div>

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