svn commit - mysqldoc@docsrva: r22345 - trunk/refman-5.5

[john.russell]

Author: jrussell
Date: 2010-08-20 00:58:55 +0200 (Fri, 20 Aug 2010)
New Revision: 22345

Log:
Added intro text explaining the overall purpose and groupings for
the InnoDB-related I_S tables.


Modified:
   trunk/refman-5.5/information-schema-innodb.xml


Modified: trunk/refman-5.5/information-schema-innodb.xml
===================================================================
--- trunk/refman-5.5/information-schema-innodb.xml	2010-08-19 21:28:08 UTC (rev 22344)
+++ trunk/refman-5.5/information-schema-innodb.xml	2010-08-19 22:58:55 UTC (rev 22345)
Changed blocks: 3, Lines Added: 69, Lines Deleted: 4; 3586 bytes

@@ -8,6 +8,71 @@
   <title><literal>INFORMATION_SCHEMA</literal> Tables for
     <literal>InnoDB</literal></title>
 
+  <para>
+    The <literal>InnoDB</literal> tables related to the
+    <literal>InnoDB</literal> storage engine serve two purposes:
+  </para>
+
+  <itemizedlist>
+
+    <listitem>
+      <para>
+        You can monitor ongoing <literal>InnoDB</literal> activity, to
+        detect inefficiencies before they turn into issues, or to
+        troubleshoot performance and capacity issues that do occur. As
+        your database becomes bigger and busier, running up against the
+        limits of your hardware capacity, you monitor and tune these
+        aspects to keep the database running smoothly. The monitoring
+        information deals with:
+      </para>
+
+      <itemizedlist>
+
+        <listitem>
+          <para>
+            <literal>InnoDB</literal> table compression, a feature whose
+            use depends on a balance between I/O reduction, CPU usage,
+            buffer pool management, and how much compression is possible
+            for your data.
+          </para>
+        </listitem>
+
+        <listitem>
+          <para>
+            Transactions and locks, features that balance high
+            performance for a single operation, against the ability to
+            run multiple operations concurrently. (Transactions are the
+            high-level, user-visible aspect of concurrency. Locks are
+            the low-level mechanism that transactions use to avoid
+            reading or writing unreliable data.)
+          </para>
+        </listitem>
+
+      </itemizedlist>
+    </listitem>
+
+    <listitem>
+      <para>
+        You can extract information about schema objects managed by
+        <literal>InnoDB</literal>, using the
+        <literal>INNODB_SYS_</literal> tables. This information comes
+        from the <literal>InnoDB</literal> data dictionary, which cannot
+        be queried directly like regular <literal>InnoDB</literal>
+        tables.
+      </para>
+    </listitem>
+
+  </itemizedlist>
+
+  <para>
+    Traditionally, you would get this type of information using the
+    techniques from <xref linkend="innodb-monitors"/>, setting up
+    <literal>InnoDB</literal> monitors and parsing the output from the
+    <literal>SHOW ENGINE INNODB STATUS</literal> command. The
+    <literal>InnoDB</literal> interface offers a simpler, familiar
+    technique to access this data.
+  </para>
+
   <section id="innodb-cmp-table">
 
     <title>The <literal>INFORMATION_SCHEMA INNODB_CMP</literal> and

@@ -25,8 +90,8 @@
 
     <para>
       The <literal role="is">INNODB_CMP</literal> and
-      <literal role="is">INNODB_CMP_RESET</literal> tables contain
-      status information on operations related to compressed
+      <literal>INNODB_CMP_RESET</literal> tables contain status
+      information on operations related to compressed
       <literal>InnoDB</literal> tables.
     </para>
 

@@ -69,8 +134,8 @@
 
     <para>
       The <literal role="is">INNODB_CMPMEM</literal> and
-      <literal role="is">INNODB_CMPMEM_RESET</literal> tables contain
-      status information on compressed pages within the
+      <literal>INNODB_CMPMEM_RESET</literal> tables contain status
+      information on compressed pages within the
       <literal>InnoDB</literal> buffer pool.
     </para>