Doc: explain that the string types can't store \0 (ASCII NUL).

This restriction was mentioned in connection with string literals,
but it wasn't made clear that it's a general restriction not just
a syntactic limitation in query strings.

Per unsigned documentation comment.

Discussion: https://postgr.es/m/160720552914.710.16625261471128631268@wrigleys.postgresql.org
This commit is contained in:
Tom Lane 2020-12-08 12:06:19 -05:00
parent b88afd8b61
commit 10c601578a
1 changed files with 9 additions and 4 deletions

View File

@ -1130,6 +1130,14 @@ 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
@ -1167,10 +1175,7 @@ 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>