Update appendix-obsolete-pgxlogdump.sgml

Author: chegong18

postgresql/doc/src/sgml/appendix-obsolete-pgxlogdump.sgml

@@ -4,13 +4,23 @@
 -->
 
 <sect1 id="pgxlogdump" xreflabel="pg_xlogdump">
+<!--==========================orignal english content==========================
   <title><command>pg_xlogdump</command> renamed to <command>pg_waldump</command></title>
+____________________________________________________________________________-->
+  <title><command>pg_xlogdump</command> 重命名为 <command>pg_waldump</command></title>
 
+<!--==========================orignal english content==========================
+   <indexterm>
+     <primary>pg_xlogdump</primary>
+     <see>pg_waldump</see>
+   </indexterm>
+____________________________________________________________________________-->
    <indexterm>
      <primary>pg_xlogdump</primary>
      <see>pg_waldump</see>
    </indexterm>
 
+<!--==========================orignal english content==========================
    <para>
     PostgreSQL 9.6 and below provided a command named
     <command>pg_xlogdump</command>
@@ -20,5 +30,11 @@
     <link linkend="release-prior">the release notes for PostgreSQL 10</link> for details
     on this change.
    </para>
+____________________________________________________________________________-->
+   <para>
+    PostgreSQL 9.6 及以下版本提供一个命令名为<command>pg_xlogdump</command> <indexterm><primary>pg_xlogdump</primary></indexterm>，用以读取write-ahead-log (WAL)文件。
+    这个命令被重命名为<command>pg_waldump</command>，<command>pg_waldump</command>的文档请见<xref linkend="pgwaldump"/>，
+    关于此变更的详细信息请参见<link linkend="release-prior">the release notes for PostgreSQL 10</link>。
+   </para>
 
 </sect1>