<?xml version="1.0" encoding="UTF-8"?><!-- generator="WordPress/2.9.2" -->
<rss version="0.92">
<channel>
	<title>Alberto Dell'Era's Oracle blog</title>
	<link>http://www.adellera.it/blog</link>
	<description>A blog about Oracle - Un blog riguardo Oracle</description>
	<lastBuildDate>Mon, 17 May 2010 20:16:14 +0000</lastBuildDate>
	<docs>http://backend.userland.com/rss092</docs>
	<language>en</language>
	
	<item>
		<title>Xtrace: an Oracle session trace browser &#8211; exec flow</title>
		<description><![CDATA[Tracing a session is extremely useful when you need to investigate how  a client interacts with the database - the client could be an application of yours, a third-party application, or an Oracle module such as dbms_stats or dbms_mview.  To get the perfect picture of the client-server dialogue,  you "simply" need to consider all EXEC lines in the trace file, and associate to each line the executed statement and the bind variable values; a very tedious and error-prone task  when done manually, that <a href="http://www.adellera.it/xtrace">Xtrace</a>  can make for you (and for free).]]></description>
		<link>http://www.adellera.it/blog/2010/05/17/xtrace-an-oracle-session-trace-browser-exec-flow/</link>
			</item>
	<item>
		<title>An improved OakTable web site</title>
		<description><![CDATA[Today the new OakTable web site, www.oaktable.net, has been published: many thanks to Kurt Van Meerbeeck (that I'm told worked the most on the site), James Morle and Marco Gralike!
I really like (besides the light and modern look) the aggregator of the OakTable members' blogs - a window on high-quality news and investigations about Oracle [...]]]></description>
		<link>http://www.adellera.it/blog/2010/04/23/an-improved-oaktable-web-site/</link>
			</item>
	<item>
		<title>Xtrace: an Oracle session trace browser (introduction)</title>
		<description><![CDATA[<a href="http://www.adellera.it/xtrace">Xtrace</a> is a graphical tool that can navigate Oracle trace files, manipulate them, and optionally get them back as a text file. It actually makes (much) more, but in this first post we are going to focus on its basic browsing capabilities.]]></description>
		<link>http://www.adellera.it/blog/2010/04/08/xtrace-an-oracle-session-trace-browser-introduction/</link>
			</item>
	<item>
		<title>fast refresh of join-only MVs: _mv_refresh_use_stats and locking log stats</title>
		<description><![CDATA[A devastating performance degradation of materialized view fast refreshes can happen in versions after 9i - and can be healed rather easily by simply setting the hidden parameter _mv_refresh_use_stats or, a bit surprisingly, by locking statistics on the logs. The problem can manifest at least in the currently-latest patchsets of 10g, 11gR1 and 11gR2 (10.2.0.4, [...]]]></description>
		<link>http://www.adellera.it/blog/2010/03/11/fast-refresh-of-join-only-mvs-_mv_refresh_use_stats-and-locking-log-stats/</link>
			</item>
	<item>
		<title>xplan: dbms_metadata.get_ddl for tables referenced by the plan</title>
		<description><![CDATA[As a minor but useful new feature, xplan is now able to integrate into its report the DDL of tables (and indexes) referenced by the plan, calling dbms_metadata.get_ddl transparently. 
This is mostly useful to get more details about referenced tables' constraints and partitions definition - to complement their CBO-related statistics that xplan reports about.
This feature [...]]]></description>
		<link>http://www.adellera.it/blog/2010/02/09/xplan-dbms_metadataget_ddl-for-tables-referenced-by-the-plan/</link>
			</item>
	<item>
		<title>tweet &#8230;</title>
		<description><![CDATA[For people that have asked - I'm not blogging simply because I'm feverishly working on a tool of mine that I'm very fond of :)
Guess what it does from the following next two screenshots ...


]]></description>
		<link>http://www.adellera.it/blog/2010/01/06/tweet/</link>
			</item>
	<item>
		<title>11gR2: new algorithm for fast refresh of on-commit materialized views</title>
		<description><![CDATA[This post investigates the improvements that have been made in 11gR2 to the fast refresh engine of materialized views (MVs) that are set to be automatically refreshed at commit time. We speak about join-only materialized views only in this post, as always with the help of a test case.
As noted in the post of mine [...]]]></description>
		<link>http://www.adellera.it/blog/2009/11/22/11gr2-new-algorithm-for-fast-refresh-of-on-commit-materialized-views/</link>
			</item>
	<item>
		<title>11gR2: materialized view logs changes</title>
		<description><![CDATA[In this post we are going to discuss some 11gR2 changes to materialized view logs that are aimed at increasing the performance of the fast-refresh engine of materialized views (MVs), especially the on-commit variant. 
The MV logs, in 10gr2, now comes in two flavours: the traditional (and still the default) timestamp-based one and the brand [...]]]></description>
		<link>http://www.adellera.it/blog/2009/11/03/11gr2-materialized-view-logs-changes/</link>
			</item>
	<item>
		<title>CBO: NewDensity for Frequency Histograms,11g-10.2.0.4 (densities part IV)</title>
		<description><![CDATA[As we have seen in the previous posts of this series, in 11g a new figure named "NewDensity" has been introduced as a replacement for the "density" column statistic for columns whose histogram has been collected; this change has been backported in 10.2.0.4 also. 
In the previous post we discussed how NewDensity influences the CBO [...]]]></description>
		<link>http://www.adellera.it/blog/2009/10/23/cbo-newdensity-for-frequency-histograms11g-10204-densities-part-iv/</link>
			</item>
	<item>
		<title>CBO: &#8220;NewDensity&#8221; replaces &#8220;density&#8221; in 11g, 10.2.0.4 (densities part III)</title>
		<description><![CDATA[In this post we are going to explore and explain the rationale for the formula used by the CBO to compute the "NewDensity" figure that replaces, from 10.2.0.4 onwards, the "density" column statistic in the cardinality estimation formulae for columns with height-balanced (HB) histograms defined.
In a previous post, we already discussed the pre-10.2.0.4 scenario: we [...]]]></description>
		<link>http://www.adellera.it/blog/2009/10/16/cbo-newdensity-replaces-density-in-11g-10204-densities-part-iii/</link>
			</item>
</channel>
</rss>
