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Welcome to Log Buffer, the weekly roundup of database industry news.

For your reading pleasure this week we have Log Buffer #196:

Charles Hooper blogs about an in-depth investigation on what can cause Oracle to ignore a hint.

Doug Burns reminds his readers that there are only two weeks left to submit papers for UKOUG. The deadline is Aug. 2.

A while back Greg Rahn at Structured Data blog thought that the best way to get results out of Exadata is by changing your application to get the most out of Exadata. He was very happy to see that Pythian thinks the same. On the subject of Exadata and data warehousing, Greg posts this week on the core performance fundamentals of Oracle Data Warehousing – set processing vs row processing.

Jonathan Lewis links to instructions and explanations on how to switch to a different UNDO tablespace. It is trickier than it sounds and Jonathan provided additional traps to watch out for.

Jonathan also continues his fragmentation series with an explanation of table fragmentation and its causes.

Alex Fatkulin explains about ASM mirroring and disk partnership and why you may have less redundancy than you thought.

On the same subject, Jeremy Schneider of Ardent Performance blog explains about hot disks, raid and what it means for ASM mirroring.

Back to blogging after a recent trip to TechInsights 2010, Edwin Sarmiento answers questions on what needs to be done as part of the installation of a SQL Server 2008 R2 Failover Cluster on Windows Server 2008 R2. A number of things related to Windows Clustering need to be considered.

Willie Favero introduces the “IBM zEnterprise System”, on his blog Getting the Most out of DB2 for z/OS and System z.

On Join-fu! the Art of SQL blog, Jay Pipes talks about getting started developing Nova on Linux, as he’s involved in a new OpenStack project.

Peter Zaitsev, on MySQL Performance Blog, posts about estimating replication capacity so that replication load can be dealt with before slave is unable to catch up.

Paul Randal publishes his survey results around the purchase and use of SSIDs.

And, if you happen to be attending Oracle OpenWorld, register before July 30 to take advantage of early bird rates.

A short post marks Pythian’s 195th edition of Log Buffer, a blog of blogs encapsulating what’s going on in the world of database administration.

Remember if you find a link or interesting blog post that you think Log Buffer should mention, send a note to the editor at Log Buffer and be sure to include the link, and a short note on why you think that others will want to read it too.

Now on to Log Buffer #195. Alex Gorbachev starts us off with his suggested readings and funnily enough, Chen Shapira had many of the same favorites this week.

Jonathan Lewis introducing a new series about fragmentation. In this post he defines what he means by fragmentation. Alex is looking forward to reading the next bits.

Charles Hooper shows how to present performance data in visually pleasing charts.

Mark Calahan, on his High Availability MySQL blog announces a new book on MySQL replication and high availability from Charles, Mat and Lars, stating it’s a good read to save people from some inevitable failures when distributed systems are deployed for enought time over many servers.

Tanel Poder, back blogging full force shows what really happens when you drop a table, and why you can drop tables from a read-only tablespace.

Maria Colgan from Oracle Optimizer Team drills into details of CURSOR_SHARING. By the way, Oracle Optimizer blog has moved to the official Oracle blogs as Doug Burns noted. And he couldn’t resist mentioning another post from Maria Colgan about moving from the old Rule-Based Optimizer to the Cost-based Optimizer. Alex saw Maria speak at ODTUG/Kaleidoscope and since then follows her blog all the time. There are lots of other recently posted materials in the new location so read on.

Randolf Geist, Oracle ACE, and member of the OakTable Network, posted a monstrous (size-wise) article about limitations of index and table compression covering Oracle release from 9i up to the latest 11.2. Very thorough!

Michael Janke complains about the number of severe bugs in Oracle and tells some amusing anecdotes about defective parts in the industry.

Michelle Gutzait suggests a new free eBook available now on how to do performance tuning with Data Management Views in SQL Server.

Joshua Drake notes the call for papers for PgWest 2010 is now open and provides the link to submit your talk. Deadline for submission is September 5, 2010 and speakers will be notified the following week. They’re looking for general PostgreSQL and stack topics and tutorials.

Until next week.

We’re well into summer and almost at our 200th edition of Log Buffer, a blog of blogs about the database world.

Remember if you find a link or interesting blog post that you think Log Buffer should mention, send a note to the editor at Log Buffer and be sure to include the link, and a short note outlining why you think that particular post would be of value to other DBAs, or what you learned from reading it.

Now on to our weekly reading in Log Buffer #194:

Oracle Exadata is a topic that is getting hotter and hotter. Following Pythian’s announcement of Exadata services Oracle’s Greg Rahn stresses how important it is to “capitalize on the opportunity to re-engineer with Exadata and fully exploit the power of the Oracle Database Machine platform”. Also speaking of Exadata, Kerry Osborne talks on his blog, about the Oracle 11g Release 2 new feature, Parallel Queuing, and how it applies to data warehousing workloads on Exadata. Marc Fielding begins his grand tour of Exadata, writing to share his implementation experience.

Jamie Thomson outlines a number of reasons why a SQL server or BI developer should learn .net. And with more activity on SQLblog.com, Jonathan Kehayias writes about a bug in SQL Server 2008 and why you shouldn’t create large tables in the Model Database.

On In Recovery, Paul Randal posts on Benchmarking: Introducing SSDs (Part 2 – Sequential Inserts), following his first set of tests and analysis of the results. In Part 1 and Part 1b he covers not overloaded log file array.

Willie Favero addresses the demise of private protocol, one last time (he hopes) on his blog Getting the Most out of DB2 for z/OS and System z.

Ronald Bradford posts a quick one on installing MYSQL on Oracle Enterprise Linux and other good advice for optimizing SQL performance using the art of elimination.

Barry Leslie announces PBMS is now in the Drizzle tree.

And to sum things up, Gwen Shapira shares a few of her favorite recent archives, a little older than our weekly news, but valuable nontheless.

Not strictly a database topic, but certainly an important lesson for data architects. Brian Carper shares the difficult life of an edge case. Keep him in mind next time you develop an online shop. The same Brian Carper shares why he migrated from MySQL to NoSQL (Tokyo Cabinet) and why he moved back to SQL (Postgres this time).

Joshua Drake warns the end of life is near for Postgres 7.4, 8.0 and 8.1 and that anyone using these versions should upgrade.

Jonathan Lewis explains the difference between unrecoverable and nologging operations.

Martin Widlake gives an overview and demonstration of a little know view, DBA_TAB_MODIFICATIONS.

And, lastly to close things off on a light note, Iggy Fernandez highlights some of his favorite Dilbert-on-Databases Cartoons.

Welcome to Log Buffer, the weekly roundup of DBA industry happenings.

Read on for the latest updates in Log Buffer #193. Don’t forget, we’re always looking for volunteer editors to publish and host an issue of Log Buffer. If you’d like this to be you, contact the Log Buffer coordinator.

ODTUG/Kaleidoscope 2010 roundup:

Sheeri Cabral has posted slides and a summary of the first ever MySQL track at ODTUG/Kaleidoscope, citing a successful event.

Tim Hall, on Oracle-Base blog gives a daily report on the event summarizing his take on day 1 & 2, 3, 4, and 5.

Following the ODTUG/Kaleidoscope Oracle ACE Director’s briefing Alex Gorbachev continues the conversation on best practices with a blog post and encourages you to add your comments.

Marc Fielding, of Pythian’s consulting group suggests the following reads this week:

Pinal Dave who tries to clear up confustion and misconceptions about Statistics on SQL Blog Authority.

SQL Master noting a SQL Server 2008 Security gotcha, from a discussion he has on sql server security during interactions with the SASSUG user group.

On SQL Aloha, a post from Brad McGhee, who poses the question: Does your company have a SQL server DR plan? A quick poll he conducted provides scary results and he offers a list of resources for DBAs without a complete and tested DR plan in place.

Sramana Mitra, who writes about Oracle’s next move: data security, now that the Sun acquisition is complete.

OracleNerd outlining strategies for how to receive free passes to Oracle OpenWorld 2010.

Peter Finnigan talking about database forensics on his Oracle security blog, and the release of a new redo log mining tool to extract DDL from redo logs.

In other news, Willie Favero gives readers a heads up that the DB2 Catalog and directory are about to go through some major changes.

Guiseppe Maxia, The Data Charmer, learns a new programming language as he tries to integrate MySQL Sandbox and Cluster.

Dave Page on his Postgres blog, highlights what SQL injection attacks are and how DBAs can avoid them after another malicious attack targeting websites running Microsoft Internet Information Server (IIS).

Happy Canada Day for those north of the border, and for our friends to the south, Happy Independence Day and enjoy a great 4th of July weekend.

It’s Friday, and summer’s here. While it seems the industry is slowing down to a lazy pace, there is still some action so let’s splash right in to this week’s edition of Log Buffer DBA industry news in Log Buffer #192.

Alex Gorbachev had a few minutes to suggest the following interesting tidbits to me before running off to attend Oracle ACE Director activities at ODTUG/Kaleidoscope this weekend. One of these days we’ll have to see if he can share some of what goes on behind closed doors at those hush hush sessions.

He’s happy fellow OakTable member and Oracle ACE Director Tanel Poder is back to blogging with low-level undocumented internals for Oracle troubleshooting geeks.

Also an OakTable Network member, Jonathan Lewis, posted about the experience of one client migrating to 64 bit and increasing their SGA to see performance going down. The moral of this story is make sure your memory configuration is right.

Tom Kyte continues a series of blog posts about things he’s learning and likes, this time on SQL*Plus. And, at the same time includes something he doesn’t like, a feature in Windows 7 that he has mixed feelings on.

In the SQL Server world:

On his blog, In Recovery, Paul S. Randal runs some experiments to explore whether multiple data files can lead to an improvement in performance.

Adam Machanic smashes a DMV Myth: session_id > 50 == User Process on SQL blog.com.

Pinal Dave has two interesting posts this week on SQL Authority.com. In the first he shares his experience meeting and learning from trainer and industry guru Bryan Oliver. Secondly, he provides valuable advice for SQL Server developers dealing with XML from friend Jacob Sebastian on Select * FROM XML which he suggests looking at before reading his own advice on the same topic.

We continue to see the traction of MySQL within Oracle communities. More and more user group and Oracle-focused events are adding MySQL content to their agendas. At ODTUG/Kaleidoscope, Sheeri Cabral and Ronald Bradford were instrumental in developing the MySQL track of 19 sessions, and are speaking themselves.

Aleksander Kuzminsky announced that Percona Server 5.1.47-rel11 is available for download, noting new features and fixed bugs.

Craig Mullins writes how to access your DB2 Catalog “Poster” online for any of you constantly looking for DB2 Catalog table and column names.

Dave Page does a bit of comparison and gives his opinion on VoltDB, the new database server architected by the ‘father’ of Postgres, Dr Michael Stonebraker.

Until next week.

I found I never published this post as it was sitting in my drafts few months now — it was written in 13th February, 2010. I’m publishing it without any changes.

I learn therefore I am!

I’ve just wrote few bits about learning a new technology and after skimming through my Google Reader, I noticed a great post by Chen Shapira — Deliberate Practice. That’s reminded me about another aspect of learning that I didn’t mention — learning is a continuous process.

There are two aspects…

• No matter how good I am and how much I know, my knowledge and expertize become outdated relatively quickly these days unless I keep up with the new stuff. Unfortunately, there is so much new technologies these days that I have to be very selective on what I want to follow which is a big challenge in itself. On the other hand, I’d rather be challenged than bored. As DBA’s we are luckier than Developers — their world changes much faster than ours.
• I forget things I don’t use/do/read about/think about regularly. Refreshing my “old” memory is a must do. This is why I think Chen’s idea of deliberate practice is so great.

Some people are better on keeping the existing tools sharp, while others succeed on the lookout for new ways and techniques. To truly excel, we need to master both.

This photo (it was taken 5 years ago in Australia in one of Sydney’s “wild” parks) reminds me of this continuous learning process — perhaps, it will do the job for you as well.

Welcome to Log Buffer, the weekly roundup of database blogs.

Kicking off this week in Log Buffer #191 are posts from Alisher Yuldashev:

Randolf Geist blogs on an Advanced Oracle Troubleshooting Session – PGA/UGA memory fragmentation for when a batch process takes significantly longer than expected.

James Morle talks about an example of a misleading average in Log File Sync and AWR – Not Good Bedfellows.

And a few faves from Bradd Piontek:

Marco Gralike, on Blog.Gralike.Com, revisits Enabling and Disabling Database Options, a small item that is easily overlooked. Marco also notes a cool tool: VirtualBox Appliance which makes a great start-up test environment. Word of caution however, it’s for testing purposes only.

On Askdba.org, Amit advises on downloading Oracle software directly to server in a post based on Pythian’s downloading from OTN directly to your database server. Watch for future posts from Brad on how he does it via Firefox, and edelivery.oracle.com.

Alex Gorbachev is spreading the word about The Ultimate SQL Tune-off with Jonathan Lewis and Kyle Hailey, two of his most respected Oracle performance experts, believing the session should be interesting to all DBAs, not just Oracle.

Robert Catteral continues to recap session highlights from the International DB2 Users Group Conference last month in Nuggets from DB2 by the Bay, Part 3, following Parts 1 & 2.

Chen Shapira contributed Cloning Oracle Home from RAC to Stand-Alone.

On In Recovery, Paul Randal wrote the whitepaper Proven SQL Server Architectures for High Availability and Disaster Recovery he wrote for the Spring SQL Server release has been published.

Moving to MySQL world, Vadim Tkachenko continues storage benchmarking of MySQL FlashCache (very much like Oracle FlashCache but for MySQL InnoDB engine). This time he is using FusionIO cards for FlashCache.

And, to round things off, Ronald Bradford writes about When SET GLOBAL affects SESSION scope.

Have a great weekend everyone.

Welcome to Log Buffer, the weekly roundup of database blogs. We’re back this week with a short Log Buffer #190. Only ten more issues, and we’ll be celebrating our 200th edition post.

Chen Shapira was eager to share news early this week, sending along her favorite picks on Tuesday.

Prof. Neil Gunther doesn’t like the way commercial load testing software distributes think times.

Miladin Modrakovic wants to add columns to a table and initialize them with values. When the table is huge, updates can take too long. No worries! Datapump will save the day!

Tom Kyte is upset because a vendor sent him his password by email.

Iggy Fernandez had fun at NoCOUG’s Spring Conference, as demonstrated in the pictures from the event.

Charles Hooper posted a small series on how column order in the query can impact performance. Sometimes. Maybe.

Chris Presley contributed a few good SQL Server archive articles:

One which talks about data compression commands in SQL 2008 and 2008 R2. And another which highlights a difference in SQL Business Development Studio (SQL BIDS) between SQL 2008 and 2008 R2 for anyone that uses SQL Integration Services (SSIS).

In Postgres news, Dave Page compares VoltDB to Postgres.

PGCon2010 ended this week with positive reviews on the “Hall Track” from The Endpoint Team.

For MySQL, Vadim posts FlashCache: tpcc workload – the last in a series on FlashCache testing when the cache is placed on Intel SSD card.

Ronald Branford notes in MySQL Best Practices: User Security – that it is critical that to not use the default MySQL installation security because it’s insecure.

Lastly we wrap up with a few more were archives added by Alex Fatkulin that didn’t get out last week.

Timing Improvements in Oracle 11GR2 and tips for the case of a slow lookup.

Until next week.

Welcome to Log Buffer, a weekly review of the database industry. This week’s issue Log Buffer #189 is generously published by Iggy Fernandez, editor of the quarterly journal of the Northern California Oracle User Group (NoCOUG).

As always, if you’d like to host your own issue of Log Buffer, simply reach out to the Log Buffer coordinator.

Please enjoy Iggy’s issue of Log Buffer #189.

Most database companies would be proud to say that their products perform optimally out of the box. It means they accomplished a Herculean feat of engineering. But most databases have configuration options because this is almost impossible. For example, MySQL has scores of tuning options, and it needs a lot more.

So when someone benchmarks your database and makes you look bad, usually you can say “that benchmark was run by someone who doesn’t know how to properly tune my database software.”

But what if the benchmarker claims that your database didn’t need to be tuned, (via Dave Page), because it’s optimal out of the box? Do you accept the benchmark results, or reject the compliment?

Related posts:

1. A review of Optimizing Oracle Performance by Cary Millsap Optimizing
2. Cary Millsap: Thinking Clearly about Performance Cary Mills
3. A review of Forecasting Oracle Performance by Craig Shallahamer Forecastin

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