From: Tom Lane <tgl@sss.pgh.pa.us>
To: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: bugs-postgresql@antipoul.fr
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: Mention invalid null byte sequence
Date: Mon, 07 Dec 2020 15:27:22 -0500
Message-ID: <3153759.1607372842@sss.pgh.pa.us> (raw)
In-Reply-To: <0f0470f6d8c543793d2b71913cb230daea1aef3a.camel@cybertec.at>
References: <160720552914.710.16625261471128631268@wrigleys.postgresql.org>
<0f0470f6d8c543793d2b71913cb230daea1aef3a.camel@cybertec.at>
Laurenz Albe <laurenz.albe@cybertec.at> writes:
> On Sat, 2020-12-05 at 21:58 +0000, PG Doc comments form wrote:
>> The following documentation comment has been logged on the website:
>> Page: https://www.postgresql.org/docs/13/datatype-character.html
>> Description:
>>
>> So it should written in the character type that null byte are not accepted,
>> it would make like easier to migrate to PostgreSQL :)
> +1; how about the attached patch?
I had thought that this was already documented, but after digging around
I can only find it mentioned in the contexts of saying that literal
strings and quoted identifiers can't contain \0. So yeah, we need to
improve that.
I agree with the submitter that the place one would expect to read about
this is in datatype-character.html. So I'd propose the attached.
Maybe there's reason to repeat the info in charset.sgml, but it seems
like more of a datatype limitation than a character set issue.
regards, tom lane
Attachments:document-that-you-cant-store-NUL.patch (text/x-diff, 1.3K) downloaddiff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgmlindex 5c8a92e250..9eb19a1c61 100644--- a/doc/src/sgml/datatype.sgml+++ b/doc/src/sgml/datatype.sgml@@ -1209,6 +1209,14 @@ SELECT '52093.89'::money::numeric::float8;
regular expressions.
</para>
+ <para>+ The characters that can be stored in any of these data types are+ determined by the database character set, which is selected when+ the database is created. Regardless of the specific character set,+ the character with code zero (sometimes called NUL) cannot be stored.+ For more information refer to <xref linkend="multibyte"/>.+ </para>+
<para>
The storage requirement for a short string (up to 126 bytes) is 1 byte
plus the actual string, which includes the space padding in the case of
@@ -1246,10 +1254,7 @@ SELECT '52093.89'::money::numeric::float8;
<para>
Refer to <xref linkend="sql-syntax-strings"/> for information about
the syntax of string literals, and to <xref linkend="functions"/>
- for information about available operators and functions. The- database character set determines the character set used to store- textual values; for more information on character set support,- refer to <xref linkend="multibyte"/>.+ for information about available operators and functions.
</para>
<example>
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To: pgsql-docs@postgresql.org
Cc: tgl@sss.pgh.pa.us, laurenz.albe@cybertec.at, bugs-postgresql@antipoul.fr, pgsql-docs@lists.postgresql.org
Subject: Re: Mention invalid null byte sequence
In-Reply-To: <3153759.1607372842@sss.pgh.pa.us>
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