Update Japanese FAQ.

Jun Kuwamura

doc/src/sgml/release.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.515 2007/10/05 04:03:41 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.516 2007/10/10 13:43:42 momjian Exp $ -->
 <!--
 
 Typical markup:
@@ -48,14 +48,16 @@ do it for earlier branch release files.
     <title>Overview</title>
 
     <para>
-     This release adds many improvements that were requested by users,
+     This release adds major new capabilities to the
+     <productname>PostgreSQL</> database system, including:
      including:
 
     <itemizedlist>
 
       <listitem>
        <para>
-        Full text search is now a built-in feature
+        Full text search now fully integrated into the core database
+        system
        </para>
       </listitem>
 
@@ -68,13 +70,14 @@ do it for earlier branch release files.
 
       <listitem>
        <para>
-        enum data types
+        Enumerated (enum) data types
        </para>
       </listitem>
 
       <listitem>
        <para>
-        UUID data type, similar to that defined by RFC 4122
+        Universally Unique Identifier (UUID) data type, similar to that
+        defined by RFC 4122
        </para>
       </listitem>
 
@@ -86,32 +89,34 @@ do it for earlier branch release files.
 
       <listitem>
        <para>
+        Control of whether <literal>NULL</>s sort first or last, using
         <literal>ORDER BY ... NULLS FIRST/LAST</>
        </para>
       </listitem>
 
       <listitem>
        <para>
-        Updatable cursors
-        (<literal>UPDATE/DELETE WHERE CURRENT OF</>
-        <replaceable>cursor_name</>)
+        Updatable cursors using <literal>UPDATE/DELETE WHERE CURRENT OF</>
+        <replaceable>cursor_name</>
        </para>
       </listitem>
 
       <listitem>
        <para>
-        Per-function parameter settings
+        Per-function server configuration parameter settings
        </para>
       </listitem>
 
       <listitem>
        <para>
-        User-defined types can now have type modifiers (parameters)
+        User-defined types can now have type modifiers
        </para>
 
        <para>
-        Declarations such as <type>varchar(42)</type> are no longer
-        restricted to use by built-in data types.
+        This allows a user type to take an optional modifier when 
+	being created, e.g. <type>SSNUM(7)</>.  Previously only
+	predefined system data types would allow this, e.g.
+	<type>CHAR(4)</>.
        </para>
       </listitem>
 
@@ -128,10 +133,10 @@ do it for earlier branch release files.
 
       <listitem>
        <para>
-        Numerous improvements in logging and statistics collection
-        capabilities, including the ability to emit postmaster log messages
-        in CSV format that can be directly loaded into a database table
-        for analysis
+        Numerous improvements in logging and statistics collection,
+        including the ability to emit postmaster log messages in
+        <acronym>CSV</> format, which can be loaded into a database
+        table for analysis
        </para>
       </listitem>
 
@@ -147,21 +152,24 @@ do it for earlier branch release files.
        </para>
 
        <para>
-        Autovacuum is now considered mature enough to be enabled by default.
+        This allows multiple vacuums to run concurrently, meaning
+        vacuuming of a large table will not prevent smaller tables from
+        being vacuumed at the same time. Autovacuum is now considered
+        mature and therefore is enabled by default.
        </para>
       </listitem>
 
       <listitem>
        <para>
-        The entire <productname>PostgreSQL</productname> system can
-        now be compiled with Microsoft Visual C++
+        The backend database server can now be compiled with
+        <productname>Microsoft Visual C++</>
        </para>
 
        <para>
-        This will improve the ability of Windows-based developers to
-        contribute to the project.  Windows executables made with Visual C++
-        may also have better stability and performance than those made with
-        other tool sets.
+         Windows executables made with Visual C++ might have better
+         stability and performance than those made with other tool sets.
+         Development and debugging tools familiar to Windows developers
+         will also work.
        </para>
       </listitem>
 
@@ -173,32 +181,41 @@ do it for earlier branch release files.
 
       <listitem>
        <para>
-        Asynchronous commit option to allow transactions to be reported
-        committed before they have actually been flushed to disk
+        Asynchronous commit option allows transactions to be committed
+        but on-disk change to be delayed
        </para>
 
        <para>
-        This would not, of course, be acceptable if the client takes some
-        critical external action on the assumption that the transaction
-        will be remembered; but for certain applications, it is an acceptable
-        risk for some or all transactions to use this mode.  Unlike existing
-        options such as <varname>fsync</varname>, asynchronous commit does
-        not risk database corruption; the worst case is that after a crash,
-        the last few reportedly-committed transactions will not have
-        taken effect.
+        This feature dramatically increases performance for data
+        modification queries. The disadvantage is that because on-disk
+        changes are delayed, if the operating system crashes before data
+        is written to the disk, committed data will be lost. This is
+        only useful for applications that can accept some data loss.
+        Unlike <varname>fsync</varname>, asynchronous commit does not
+        risk database corruption; the worst case is that after an
+        operating system crash, the last few reportedly-committed
+        transactions will be missing.
        </para>
       </listitem>
 
       <listitem>
        <para>
-        <quote>Distributed</> checkpoints to spread out the I/O load of a
-        checkpoint
+        <quote>Distributed</> checkpoints prevent I/O spikes during
+        checkpoints
        </para>
       </listitem>
 
       <listitem>
        <para>
-        Heap-Only Tuples (HOT) to reduce overhead of updates
+        Heap-Only Tuples (<acronym>HOT</>) reduce overhead of updates
+       </para>
+
+       <para>
+        To allow high concurrency <productname>PostgreSQL</> retains old
+        versions of updated rows. Previously only <command>VACUUM</>
+        could reuse space taken by dead rows. With <acronym>HOT</> dead
+        row space can be reused at the time of <command>UPDATE</> or
+        <command>INSERT</>. This allows for more consistent performance.
        </para>
       </listitem>
 
@@ -207,12 +224,21 @@ do it for earlier branch release files.
         Just-in-time background writer strategy to improve disk write
         efficiency
        </para>
+
+       <para>
+        This basically makes the background writer self-tuning.
+       </para>
+
       </listitem>
 
       <listitem>
        <para>
-        Reduction of on-disk data size through reducing both per-tuple
-        and per-field overheads
+        Reduction of both per-field and per-row storage requirements
+       </para>
+
+       <para>
+        For example, two <type>CHAR(1)</type> fields now take 4 bytes
+        instead of 16.
        </para>
       </listitem>