Striving for Optimal Performance (Christian Antognini)

PerformaSure X-Agent Configuration

Striving for Optimal Performance — Mon, 05 Jan 2009 17:47:42 GMT

PerformaSure of Quest Software is a J2EE performance diagnosis tool that provides an end-to-end transaction-centric view of performance as experienced by end users. To gather profile information PerformaSure uses one or several agents deployed on the...(read more)

What Are Hints?

Striving for Optimal Performance — Mon, 22 Dec 2008 07:43:32 GMT

Yesterday, while reading a swiss italian dialect tranlation of Le petit prince (entitled Ul principe pinin), I noticed a very interesting discussion between the little prince and the king (the inhabitant of the first planet visited by the little prince…...(read more)

Automatic Evolution of SQL Plan Baselines

Striving for Optimal Performance — Wed, 10 Dec 2008 16:00:53 GMT

In the section Evolving SQL Plan Baselines of TOP (pages 299-300) I explain what an evolution is and how to manually do it. What I do not cover is the automatic evolution. In fact, I wrote only the following text about it: “In addition to the manual...(read more)

Query Optimizer 11g – What’s new?

Striving for Optimal Performance — Tue, 02 Dec 2008 21:01:09 GMT

Today I presented at the DOAG Conference in Nuremberg. As the title of this post suggests, I talked about the query optimizer features introduced in Oracle Database 11g. This is an evolution of the paper I already presented at the UKOUG Conference in...(read more)

DBMS_XPLAN.PREPARE_PLAN_XML_QUERY

Striving for Optimal Performance — Fri, 21 Nov 2008 11:11:39 GMT

As of 11.1.0.7 in the package dbms_xplan there is a new function: FUNCTION prepare_plan_xml_query(plan_query IN VARCHAR2) RETURN VARCHAR2; Simply put, the function takes as input a query that extract information from a plan table (e.g. plan_table or v...(read more)

TVD$XTAT 4.0 Beta 8

Striving for Optimal Performance — Mon, 17 Nov 2008 20:08:13 GMT

This is just a short note to point out that I just uploaded under the section Downloadable Files of TOP a new version of TVD$XTAT. The change log since Beta 7 is the following: Improved generation of synthetic cursors (particularly for RPC and XCTEND...(read more)

Hotsos Symposium 2009

Striving for Optimal Performance — Thu, 13 Nov 2008 05:00:27 GMT

Every March since 2004 I use to spend several days in Dallas. The reason is quite simple… people from around the world sharing my own interests gather there to attend Hotsos Symposium. If, like me, you are focusing on getting the most out of Oracle, this...(read more)

Invisible Indexes and Hints

Striving for Optimal Performance — Tue, 11 Nov 2008 16:02:32 GMT

In this post I would like to remove some misinformation about the utilization of hints with invisible indexes. Let’s start by providing you what two sources say about that topic: Oracle Database 11g: New Features for DBAs and Developers (by Sam R. Alapati...(read more)

Introduce TVD$XTAT

Striving for Optimal Performance — Fri, 24 Oct 2008 13:56:51 GMT

Trivadis Extended Tracefile Analysis Tool (TVD$XTAT) is a command-line tool. Like TKPROF, its main purpose is to take a raw SQL trace file as input and generate a formatted file as output. Why Is TKPROF Not Enough? In late 1999, I had my first encounter...(read more)

Invisible Indexes and Locks

Striving for Optimal Performance — Fri, 17 Oct 2008 08:33:23 GMT

Invisible indexes are useful to temporarily hide an index from the query optimizer. In this post, instead of explaining what invisible indexes are, I would like to show whether the database engine uses invisible indexes to avoid false contention caused...(read more)

TOP on Google Book Search

Striving for Optimal Performance — Fri, 10 Oct 2008 09:43:42 GMT

This is a short note to point out that my book, Troubleshooting Oracle Performance, is available on Google Book Search. To browse through it or to use the search capabilities provided by Google, click here. Even if the preview is limited to certain number...(read more)

Granularity ‘APPROX_GLOBAL AND PARTITION’

Striving for Optimal Performance — Fri, 03 Oct 2008 08:27:19 GMT

The patchset 11.1.0.7 introduces in the package DBMS_STATS a new value for the parameter GRANULARITY. The description provided by the development team in $ORACLE_HOME/rdbms/admin/dbmsstat.sql is the following: 'APPROX_GLOBAL AND PARTITION' ...(read more)

Bloom Filters

Striving for Optimal Performance — Fri, 26 Sep 2008 16:24:13 GMT

Oracle Database, as of 10g Release 2, uses bloom filters in various situations. Unfortunately, no information about their usage is available in Oracle documentation. For this reason, I decided to write a paper to explain not only what bloom filters are...(read more)

Book Presentation

Striving for Optimal Performance — Tue, 23 Sep 2008 21:40:34 GMT

I already pointed out in a previous post that Tanel Poder will be speaking in Vienna, Düsseldorf, Munich and Zürich next December. The news is that an additional presentation (followed by an aperitif) will take place at the same locations and dates as...(read more)

New Information in SQL Trace Files

Striving for Optimal Performance — Sun, 21 Sep 2008 19:34:47 GMT

During some tests with patchset 11.1.0.7 (which is presently available for Linux 32-bit and 64-bit only) I noticed something new in the SQL trace files. Let’s see what is the difference if I run the following statements with and without the patchset...(read more)