--- doc/src/sgml/ref/vacuum.sgml	2007-02-01 00:26:04.000000000 +0100
+++ /tmp/vacuum.sgml	2007-05-15 18:32:14.000000000 +0200
@@ -164,8 +164,8 @@
    <para>
     The <option>FULL</option> option is not recommended for routine use,
     but might be useful in special cases.  An example is when you have deleted
-    most of the rows in a table and would like the table to physically shrink
-    to occupy less disk space.  <command>VACUUM FULL</command> will usually
+    or updated most of the rows in a table and would like the table to physically shrink
+    to occupy less disk space and allow faster table scans. <command>VACUUM FULL</command> will usually
     shrink the table more than a plain <command>VACUUM</command> would.
     The <option>FULL</option> option does not shrink indexes; a periodic
     <command>REINDEX</> is still recommended.  In fact, it is often faster
--- doc/src/sgml/maintenance.sgml	2007-05-03 17:47:48.000000000 +0200
+++ /tmp/maintenance.sgml	2007-05-15 18:29:29.000000000 +0200
@@ -157,7 +157,8 @@
     command. This uses a more aggressive algorithm for reclaiming the
     space consumed by dead row versions. Any space that is freed by
     <command>VACUUM FULL</command> is immediately returned to the
-    operating system. Unfortunately, this variant of the
+    operating system, and the table data is physically compacted on
+    the disk. Unfortunately, this variant of the
     <command>VACUUM</command> command acquires an exclusive lock on
     each table while <command>VACUUM FULL</command> is processing
     it. Therefore, frequently using <command>VACUUM FULL</command> can
@@ -168,12 +169,15 @@
    <para>
     The standard form of <command>VACUUM</> is best used with the goal
     of maintaining a fairly level steady-state usage of disk space. If
-    you need to return disk space to the operating system you can use
+    you need to return disk space to the operating system, you can use
     <command>VACUUM FULL</> &mdash; but what's the point of releasing disk
     space that will only have to be allocated again soon?  Moderately
     frequent standard <command>VACUUM</> runs are a better approach
     than infrequent <command>VACUUM FULL</> runs for maintaining
-    heavily-updated tables.
+    heavily-updated tables. However, if some heavily-updated tables
+    have gone too long with infrequent <command>VACUUM</>, you can
+    use <command>VACUUM FULL</> to get performance back (it is much
+    slower to scan a table containing almost only dead rows).
    </para>
 
    <para>