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
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 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>