diff options
Diffstat (limited to 'doc/src/sgml/datatype.sgml')
| -rw-r--r-- | doc/src/sgml/datatype.sgml | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml index 8e30b82273c..4cc9e592708 100644 --- a/doc/src/sgml/datatype.sgml +++ b/doc/src/sgml/datatype.sgml @@ -1338,9 +1338,10 @@ SELECT b, char_length(b) FROM test2; <para> There are two other fixed-length character types in <productname>PostgreSQL</productname>, shown in <xref - linkend="datatype-character-special-table"/>. The <type>name</type> - type exists <emphasis>only</emphasis> for the storage of identifiers - in the internal system catalogs and is not intended for use by the general user. Its + linkend="datatype-character-special-table"/>. + These are not intended for general-purpose use, only for use + in the internal system catalogs. + The <type>name</type> type is used to store identifiers. Its length is currently defined as 64 bytes (63 usable characters plus terminator) but should be referenced using the constant <symbol>NAMEDATALEN</symbol> in <literal>C</literal> source code. @@ -1348,7 +1349,8 @@ SELECT b, char_length(b) FROM test2; is therefore adjustable for special uses); the default maximum length might change in a future release. The type <type>"char"</type> (note the quotes) is different from <type>char(1)</type> in that it - only uses one byte of storage. It is internally used in the system + only uses one byte of storage, and therefore can store only a single + ASCII character. It is used in the system catalogs as a simplistic enumeration type. </para> |