doc: \123 and \x12 escapes in COPY are in database encoding.

The backslash sequences, including \123 and \x12 escapes, are interpreted
after encoding conversion. The docs failed to mention that.

Backpatch to all supported versions.

Reported-by: Andreas Grob
Discussion: https://www.postgresql.org/message-id/17142-9181542ca1df75ab%40postgresql.org

diff --git a/doc/src/sgml/ref/copy.sgml b/doc/src/sgml/ref/copy.sgml
index 4807dbc371632f3fd2d6705b7a4088c433848cd9..90806a241ea058ada68617759a4e4d37649da7c9 100644 (file)
--- a/doc/src/sgml/ref/copy.sgml
+++ b/doc/src/sgml/ref/copy.sgml
@@ -599,12 +599,12 @@ COPY <replaceable class="parameter">count</replaceable>
       <row>
        <entry><literal>\</><replaceable>digits</></entry>
        <entry>Backslash followed by one to three octal digits specifies
-       the character with that numeric code</entry>
+       the byte with that numeric code</entry>
       </row>
       <row>
        <entry><literal>\x</><replaceable>digits</></entry>
        <entry>Backslash <literal>x</> followed by one or two hex digits specifies
-       the character with that numeric code</entry>
+       the byte with that numeric code</entry>
       </row>
      </tbody>
     </tgroup>
@@ -636,6 +636,12 @@ COPY <replaceable class="parameter">count</replaceable>
     or vice versa).
    </para>
 
+   <para>
+     All backslash sequences are interpreted after encoding conversion.
+     The bytes specified with the octal and hex-digit backslash sequences must
+     form valid characters in the database encoding.
+   </para>
+
    <para>
     <command>COPY TO</command> will terminate each row with a Unix-style
     newline (<quote><literal>\n</></>).  Servers running on Microsoft Windows instead