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From scotsmat...@apache.org
Subject svn commit: r572809 - in /db/derby/docs/trunk/src/tuning: ctunperf816059.dita rtunproper40688.dita rtunproper81359.dita
Date Tue, 04 Sep 2007 20:20:11 GMT
Author: scotsmatrix
Date: Tue Sep  4 13:20:07 2007
New Revision: 572809

URL: http://svn.apache.org/viewvc?rev=572809&view=rev
Log:
DERBY-2836: Clarified the default page size. Patch submitted by me.

Modified:
    db/derby/docs/trunk/src/tuning/ctunperf816059.dita
    db/derby/docs/trunk/src/tuning/rtunproper40688.dita
    db/derby/docs/trunk/src/tuning/rtunproper81359.dita

Modified: db/derby/docs/trunk/src/tuning/ctunperf816059.dita
URL: http://svn.apache.org/viewvc/db/derby/docs/trunk/src/tuning/ctunperf816059.dita?rev=572809&r1=572808&r2=572809&view=diff
==============================================================================
--- db/derby/docs/trunk/src/tuning/ctunperf816059.dita (original)
+++ db/derby/docs/trunk/src/tuning/ctunperf816059.dita Tue Sep  4 13:20:07 2007
@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
+
+<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN"
+ "../dtd/concept.dtd">
 <!-- 
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
@@ -15,21 +18,19 @@
 See the License for the specific language governing permissions and  
 limitations under the License.
 -->
-<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "../dtd/concept.dtd">
-<concept xml:lang="en-us" id="ctunperf816059">
+<concept id="ctunperf816059" xml:lang="en-us">
 <title>Performance trade-offs of large pages</title>
 <prolog><metadata>
-<keywords>
-<indexterm>Page size<indexterm>performance trade-offs of large
-pages</indexterm></indexterm>
+<keywords><indexterm>Page size<indexterm>performance trade-offs of large
pages</indexterm></indexterm>
 </keywords>
-</metadata>
-</prolog>
+</metadata></prolog>
 <conbody>
 <p>Using large database pages benefits database performance, notably decreasing
-I/O time. <ph conref="../conrefs.dita#prod/productshortname"></ph> autotunes
the database pagesize. If you have long columns, the default pagesize for the table is set
to 32K. Otherwise, the default is 4K. You can change
-the default database page size with the <i><xref href="rtunproper40688.dita#rtunproper40688">derby.storage.pageSize</xref></i>
property. For example:  
-<codeblock><b>derby.storage.pageSize=8192</b></codeblock></p>
+I/O time. <ph conref="../conrefs.dita#prod/productshortname"></ph> automatically
+tunes for the database page size. If you have long columns, the default page
+size for the table is set to 32768 bytes. Otherwise, the default is 4096 bytes.
+You can change the default database page size with the <i><xref href="rtunproper40688.dita#rtunproper40688">derby.storage.pageSize</xref></i>
property.
+For example:   <codeblock><b>derby.storage.pageSize=8192</b></codeblock></p>
 <note>Large database pages require more memory.</note>
 <p>If row size is large, generally page size should be correspondingly large.
 If row size is small, page size should be small. Another rough guideline is
@@ -43,4 +44,5 @@
 put the large column at the end of the row, so that commonly used columns
 will not be moved to overflow pages. Do not index large columns.</p>
 <p>Large page size for indexes improves performance considerably.</p>
-</conbody></concept>
+</conbody>
+</concept>

Modified: db/derby/docs/trunk/src/tuning/rtunproper40688.dita
URL: http://svn.apache.org/viewvc/db/derby/docs/trunk/src/tuning/rtunproper40688.dita?rev=572809&r1=572808&r2=572809&view=diff
==============================================================================
--- db/derby/docs/trunk/src/tuning/rtunproper40688.dita (original)
+++ db/derby/docs/trunk/src/tuning/rtunproper40688.dita Tue Sep  4 13:20:07 2007
@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
+
+<!DOCTYPE reference PUBLIC "-//OASIS//DTD DITA Reference//EN"
+ "../dtd/reference.dtd">
 <!-- 
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
@@ -15,42 +18,36 @@
 See the License for the specific language governing permissions and  
 limitations under the License.
 -->
-<!DOCTYPE reference PUBLIC "-//OASIS//DTD DITA Reference//EN" "../dtd/reference.dtd">
-<reference xml:lang="en-us" id="rtunproper40688">
+<reference id="rtunproper40688" xml:lang="en-us">
 <title>derby.storage.pageSize</title>
 <prolog><metadata>
-<keywords><indexterm>derby.storage.pageSize</indexterm><indexterm>Page
size<indexterm>configuring</indexterm></indexterm>
+<keywords><indexterm><indexterm>database properties</indexterm>derby.storage.pageSize</indexterm>
+<indexterm>derby.storage.pageSize</indexterm><indexterm>Page size<indexterm>configuring</indexterm></indexterm>
 </keywords>
-</metadata>
-</prolog><refbody>
-<section><title>Function</title>
-<p>Defines the page size, in bytes, for on-disk database pages for tables
-or indexes used during table or index creation. Page size can only be one
-the following values: 4096, 8192, 16384, or 32768. Set this property prior
-to issuing the CREATE TABLE or CREATE INDEX statement. This value will be
-used for the lifetime of the newly created conglomerates.</p>
-</section>
-<section><title>Valid conglomerates</title>
-<p>Tables and indexes, including the indexes created to enforce constraints.</p>
-</section>
-<section><title>Default</title>
-<p id="rtunproper21619">4096 bytes.</p>
-</section>
-<section><title>Valid values</title>
-<p>Page size can only be one the following values: 4096, 8192, 16384, or 32768.
-If you specify an invalid value, <ph conref="../conrefs.dita#prod/productshortname"></ph>
uses the default value 4096.</p>
-</section>
-<example><title>Example</title>
-<codeblock><b><ph>-- changing the default for the system</ph>
+</metadata></prolog>
+<refbody>
+<section><title>Function</title> <p>Defines the page size, in bytes,
for on-disk
+database pages for tables or indexes used during table or index creation.
+Set this property prior to issuing the CREATE TABLE or CREATE INDEX statement.
+This value will be used for the lifetime of the newly created conglomerates.</p> </section>
+<section><title>Valid conglomerates</title> <p>Tables and indexes,
including
+the indexes created to enforce constraints.</p> </section>
+<section><title>Default</title> <p id="rtunproper21619"><ph conref="../conrefs.dita#prod/productshortname"></ph>
automatically
+tunes for the database page size. If you have long columns, the default page
+size for the table is set to 32768 bytes. Otherwise, the default is 4096 bytes.</p>
</section>
+<section><title>Valid values</title> <p>Page size can only be one
the following
+values: 4096, 8192, 16384, or 32768 bytes. If you specify an invalid value, <ph
+conref="../conrefs.dita#prod/productshortname"></ph> uses the default value. </p>
</section>
+<example><title>Example</title> <codeblock><b><ph>--
changing the default for the system</ph>
 derby.storage.pageSize=8192
 <ph>-- changing the default for the database</ph>
 CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( 
     'derby.storage.pageSize',
     '8192')
-</b></codeblock>
-</example>
-<section><title>Dynamic or static</title>
-<p>This property is dynamic; if you change it while <ph conref="../conrefs.dita#prod/productshortname"></ph>
is running,
-the change takes effect immediately. For information about dynamic changes
-to properties, see <xref href="ctunsetprop44147.dita#ctunsetprop44147"/>.</p>
-</section></refbody></reference>
+</b></codeblock> </example>
+<section><title>Dynamic or static</title> <p>This property is dynamic;
if
+you change it while <ph conref="../conrefs.dita#prod/productshortname"></ph>
is
+running, the change takes effect immediately. For information about dynamic
+changes to properties, see <xref href="ctunsetprop44147.dita#ctunsetprop44147"></xref>.</p>
</section>
+</refbody>
+</reference>

Modified: db/derby/docs/trunk/src/tuning/rtunproper81359.dita
URL: http://svn.apache.org/viewvc/db/derby/docs/trunk/src/tuning/rtunproper81359.dita?rev=572809&r1=572808&r2=572809&view=diff
==============================================================================
--- db/derby/docs/trunk/src/tuning/rtunproper81359.dita (original)
+++ db/derby/docs/trunk/src/tuning/rtunproper81359.dita Tue Sep  4 13:20:07 2007
@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
+
+<!DOCTYPE reference PUBLIC "-//OASIS//DTD DITA Reference//EN"
+ "../dtd/reference.dtd">
 <!-- 
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
@@ -15,42 +18,37 @@
 See the License for the specific language governing permissions and  
 limitations under the License.
 -->
-<!DOCTYPE reference PUBLIC "-//OASIS//DTD DITA Reference//EN" "../dtd/reference.dtd">
-<reference xml:lang="en-us" id="rtunproper81359">
+<reference id="rtunproper81359" xml:lang="en-us">
 <title>derby.storage.pageCacheSize</title>
 <prolog><metadata>
-<keywords><indexterm>derby.storage.pageCacheSize</indexterm><indexterm>Page
cache size<indexterm>configuring</indexterm></indexterm>
+<keywords><indexterm><indexterm>database properties</indexterm>derby.storage.pageCacheSize</indexterm>
+<indexterm>derby.storage.pageCacheSize</indexterm><indexterm>Page cache
size<indexterm>configuring</indexterm></indexterm>
 </keywords>
-</metadata>
-</prolog><refbody>
-<section><title>Function</title>
-<p>Defines the size, in number of pages, of the database's data page cache
-(data pages kept in memory).</p>
-<p>The actual amount of memory the page cache will use depends on the following:
- 
-<ul>
-<li>the size of the cache (configured with this property, derby.storage.pageCacheSize)</li>
-<li>the size of the pages (configured with the <xref href="rtunproper40688.dita#rtunproper40688">derby.storage.pageSize</xref>
property)</li>
-<li>overhead (varies with JVMs)</li>
-</ul></p>
-<p>When increasing the size of the page cache, you typically have to allow
-more memory for the Java heap when starting the embedding application (taking
-into consideration, of course, the memory needs of the embedding application
+</metadata></prolog>
+<refbody>
+<section><title>Function</title> <p>Defines the size, in number of
pages,
+of the data page cache in the database (data pages kept in memory).</p><p>The
+actual amount of memory the page cache will use depends on the following:
+  <ul>
+<li>The size of the cache, configured with the <varname>derby.storage.pageCacheSize</varname>
property.</li>
+<li>The size of the pages, configured with the <xref href="rtunproper40688.dita#rtunproper40688"><varname>derby.storage.pageSize</varname></xref>
property. <ph
+conref="../conrefs.dita#prod/productshortname"></ph> automatically tunes for
+the database page size. If you have long columns, the default page size for
+the table is set to 32768 bytes. Otherwise, the default is 4096 bytes.</li>
+<li>Overhead, which varies with JVMs.</li>
+</ul></p><p>When increasing the size of the page cache, you typically have
+to allow more memory for the Java heap when starting the embedding application
+(taking into consideration, of course, the memory needs of the embedding application
 as well). For example, using the default page size of 4K, a page cache size
 of 2000 pages will require at least 8 MB of memory (and probably more, given
-the overhead).</p>
-<p>For a simple application (no GUI), using the Sun 1.1.7 JVM on Windows NT
-and using the -mx96m option (which allows 96 MB for the Java heap), it is
-possible to have a page cache size of 10,000 pages (approximately 40 MB).</p>
-<p>The minimum value is 40 pages. If you specify a lower value, <ph conref="../conrefs.dita#prod/productshortname"></ph>
uses
-the default value.</p>
-</section>
-<section><title>Default</title>
-<p>1000 pages.</p>
-</section>
-<example><title>Example</title>
-<codeblock><b>derby.storage.pageCacheSize=160</b></codeblock>
-</example>
-<section><title>Dynamic or static</title>
-<p>Static. You must reboot the system for the change to take effect.</p>
-</section></refbody></reference>
+the overhead).</p><p>For a simple application (no GUI), using the Sun 1.1.7
+JVM on Windows NT and using the -mx96m option (which allows 96 MB for the
+Java heap), it is possible to have a page cache size of 10,000 pages (approximately
+40 MB).</p><p>The minimum value is 40 pages. If you specify a lower value, <ph
+conref="../conrefs.dita#prod/productshortname"></ph> uses the default value.</p>
</section>
+<section><title>Default</title><p>1000 pages.</p> </section>
+<example><title>Example</title><codeblock><b>derby.storage.pageCacheSize=160</b></codeblock>
</example>
+<section><title>Dynamic or static</title><p>Static. You must reboot
the system
+for the change to take effect.</p> </section>
+</refbody>
+</reference>



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