Pythian Group

In record time, less than a week after the conference (thanks to the free Pinnacle Video Spin and YouTube), all 11 videos that were taken at OpenSQLCamp Europe are online.

For those who missed the sessions, or just want to relive the fun!

Almost all the sessions were filmed; regrettably Darren Cassar’s Securich – MySQL user administration and security made easy! and Stephane Combaudon’s Minimizing data access with covering indexes were not.

The YouTube videos have the descriptions and resources from the official conference pages, and links to pages. If there is more information to add (for example, the slides from a talk are now online), or if you spot an error, please feel free to add a comment on the YouTube video, or as a comment to this blog post.

• YouTube Playlist for all 11 OpenSQLCamp videos

Individual presentations:

• Spider: Sharding for the Masses – Giuseppe Maxia
• A Better mysqltuner – Sheeri Cabral (my session!)
• Getting acquainted with Apache Derby – Kristian Wagaan
• New kid on the block: The BlackRay Data Engine — Felix Schupp
• MySQL High Availability Solutions — Lenz Grimmer
• Bringing Master/Slave into the 21st Century using Tungsten Database Clustering — Linas Virbalas
• PBXT: Technology trends that affect your database — Vladimir Kolesnikov
• MySQL Proxy: a MySQL toolbox – Architecture and concepts of misuse — Jan Kneschke
• Galera Replication, multi-master synchronous replication for MySQL — Seppo Jaakola
• Panel Discussion: The OSS Toolshed Shootout Speakers and technologies: Sheeri K. Cabral – MySQL; Holger Klemt – Firebird; Felix Schupp – BlackRay; Kristian Waagan – Apache Derby (JavaDB); Lenz Grimmer – moderator; Kore Nordmann – CouchDB; Andreas ‘ads’ Scherbaum – PostgreSQL (this was a fun panel to be on)
• Firebird – a really free database used in free and commercial projects — Holger Klemt

Enjoy!

Welcome to the 151^st edition of Log Buffer, the weekly review of database blogs. We’re going to take a fast tour through the best blogs from the week gone by, beginning this time, with Oracle.

Jonathan Lewis writes, “It occurred to me recently that I might be making casual use of terms that weren’t necessarily very well known to the less experienced user. So I’ve decided to build a glossary of terms – and I’ll try to add to it from time to time whenever I have a few minutes.”

Jonathan might want to add “Method R” to the glossary. Cary Millsap was making it understood, as he shows in Profiling with my Boy: “Today I’m going to raise the stakes, because yesterday I think I explained Method R so that an eleven year-old could understand it.”

Vivek Sharma offers a thorough look at the Cost-Based Optimizer: Inefficient Input yields Inefficient Output. Vivek begins, “Cost Based Optimizer has always been a mystery for most of the Database Administrators and Developers.  . . .  Cost Based Optimizer has improved a lot in previous few versions. Therefore, it can be said that CBO is still undergoing some enhancements. With these enhancements, Oracle Users have accepted the fact that the Application Performance might degrade after version upgrade . . . ”

Randolf Geist had some info to share on the matter of locked table statistics and subsequent create index. “ . . . in 10g and later index statistics are generated along with an index creation  . . .  so a newly created index usually has computed statistics. 10g also introduced the option to lock table statistics. Now if you lock statistics in 10g in later  . . .  and create an index on a locked table the statistics for the index will not be generated along with the CREATE INDEX command.”

Rob van Wijk gave us part three of his series on fast refreshable materialized view errors: aggregate MV’s. “In the third part I’m going to examine all restrictions for aggregate materialized views, as described in the documentation.  . . .  So this will be quite a lengthy and even tedious post, as you can imagine by the list above … but for a good cause.”

Read the rest of this entry . . .

Welcome to the 145^th edition of Log Buffer, the weekly review of database blogs.

MySQL

Since MySQL was surely the belle of the bloggers’ ball this week—why, everyone was talking—let’s begin with it.

Baron Schwartz started something with his post examining why MySQL might not benefit from having a mother ship. Dean Ellis of niflheim responded, arguing that everyone needs the MySQL mothership. And that got Sheeri’s Cabral’s attention—she took the middle path in her post, What If, and her readers had plenty to say.

Justin Swanhart gave news and opinion in one headline: MySQL documentation team announces docs will NOT be GPLed. Boo MySQL. Boooo, adding, “I’m now totally convinced that MySQL does not understand, and will never understand the MySQL community.” In his piece on MySQL docs freedom, Arjen Lentz wrote, “I believe this is a serious concern for the product as a whole, and hope this concern will be addressed by Sun Microsystems very soon – with action.” Read the rest of this entry . . .

This is the 140^th edition of Log Buffer, the weekly review of database blogs. Welcome.

Let us begin with Oracle this week. Dan Norris illustrates how to start database services automatically after instance startup. He says, “Services are an essential component for managing workload in a RAC environment. If you’re not defining any non-default services in your RAC database, you’re making a mistake.”

Vivek Sharma published his tale of, Latch: Row Cache Objects causing huge performance issue. Clever detective work, a “nice catch” as Noons comments.

Riyaj Shamsudeen also was sleuthing—into dynamic_plan_table, x$kqlfxpl and extreme library cache latch contention. Dion Cho, the Oracle Performance Storyteller, responded with an item about a similar experience of his: heavy reads on the library cache related v$ views.

From detectives to cloak-and-dagger. Tanel Poder reveals the real history of Oracle database! X$KZSRT! X$KCPXPL! CCCP! KGB! CIA! Wow!

Read the rest of this entry . . .

Welcome to the 117^th edition of Log Buffer, the weekly review of database blogs.

For those of you who don’t know me, my name is Nicklas Westerlund, and I’m a MySQL DBA with The Pythian Group. This is my first time writing Log Buffer, and I hope I’ll do it right.

Let’s start off with SQL Server, where Simon Sabin asks if you know what concurrency is and how to improve it. And on SatisticsIO, Jason Massie focuses on the SQL Server 2008 experience instead, which should provide more inside knowledge of the technology used.

Continuing on with SQL Server 2008, the engineering team is sending loads of engineers to the SQL PASS Conference, as the SQL Server Customer Advisory Team tells us in their post on what, in their opinion, just may be the best PASS Conference yet. And if you’re into meeting engineers, then perhaps you’d also like to know how that patching is done in SQL Server 2008, which PSS SQL informs us about.

The folks over at sqlserver-qa.net also give us an overview of the SQL Server Web Edition.

Let’s move over to Oracle, where there’s still a lot of buzz about Exadata, and let’s start with with the second part of the Exadata FAQ by Kevin Closson. In that post he also mentions his interview on the Exadata with Paul and Christo here at Pythian.

Read the rest of this entry . . .

Welcome to the 116^th edition of Log Buffer, the weekly review of database blogs.

This was the week of Oracle Open World (OOW), Oracle’s gigantic annual get-together in San Francisco — always the heaviest week in Oracle blogs, so let’s start there.

For day-by-day coverage of OOW on the ground, I recommend Doug’s Oracle Blog: OOW Day 1, OOW Day 1.5, OOW Day 2, OOW Day 3.

Tom Kyte shared a podcast from OOW 2008, and interview with Oracle Magazine editor Tom Haunert, in which Tom, “ . . . stirs things up in this conversation about Oracle OpenWorld happenings, a new approach to publishing, and the trouble with triggers.”

Oracle teased everyone right at the beginning with word that CEO Larry Ellison’s keynote, carrying the title “Extreme Performance,” would introduce something big and new. And there was much speculation in the blogging world, some of it quite perspicacious. “Big and new” was soon going by the tantalizing nom-de-hype “X”. And before Larry’s keynote was even over (before he mothballed the black mock-turtleneck for another year), X was no longer unknown.

Writes Lucas Jellema on the AMIS Technology blog — The secret is out: Oracle launches “The Database Machine” – becoming a hardware vendor! “The big announcement that had loomed over the conference has been made. Oracle – in joint partnership with HP – introduces the world’s fastest hardware for running databases and especially data warehouses: the Exadata Storage Server.” Click through for Lucas’s précis of what it’s all about.

On blogs.oracle.com, Jack Flynn has some video excerpted from the keynote.

Lucas’s story has a picture of the thing itself, albeit a somewhat blurry one. Here’s a better image of one of the two new machines, the Exadata. Oooh, just look at it! Cor!

Read the rest of this entry . . .

This is the 114^th edition of Log Buffer, the weekly review of database blogs.

I am sorry to say that this log buffer was supposed to be edited by Dave Edwards, but he’s suffering from severe and long-lasting tooth pain and until his root canal is done he’s KO’d by a killer combo of painkillers and the pain that the painkillers can’t kill. I’ve been there myself, twice, and here’s a tip Dave. It hurts until the dentist takes out the needle. Then the pain goes away while he digs. The pain comes back that night. The next morning it’s worse than ever, unbelievably, writhingly bad. But later that afternoon, blisssssssssssss. :-) Good luck man.

This Log Buffer has been generated in a completely automated way with the help of the incredibly awesome AideRSS.

To give you an idea of just how awesome it is, I was able to load up Dave’s complete OPML file of all the blogs he monitors for Log Buffer. And AideRSS applied it’s magical PostRank algorithm which scores blog posts based on how many comments, del.icio.us bookmarks, blog links from other blogs, etc. that it received, along with some more secret sauce they don’t publicly tell us about (kind of like Google with their Pagerank equivalent). The number to the left of each headline represents the linked item’s AideRSS PostRank.

It did a great job of automatically selecting the best posts from the last week.

To give you an idea of AideRSS’s helpfulness, here are a couple useful feeds I suggest you subscribe to:

1. PlanetMySQL, but only with posts that rank “Best”
2. OraNA.info, again only the posts that rank “Best”. Note that there is a bug in Eddie’s feed that makes it impossible to use all possible information on the ranking.
3. SQLBlogs.com processed by AideRSS to show only the best posts.

While I have no idea how AideRSS plans to make moolah, I think we can agree that is some kind of awesome if you’re like me and can’t afford to miss a big story, but can’t afford the time you would need to read it all. Many thanks to Andrew Baldwin and although that’s the AideRSS about page there there’s a good pic of Andrew on that page. I first met Andrew at MySQLConf 2008 this spring and he’s a great guy and a great advocate for this service.

10.0 – Random selection, with a bias ..

Read the rest of this entry . . .

This is the 96^th edition of the weekly review of database blogs, Log Buffer.

Let’s start this one in SQL Server Land, with a question from Dennis Gobo — should SQL Server have the CREATE [OR REPLACE] PROCEDURE syntax? There are, he writes, advantages: “When scripting out a database you don’t have to generate if exists…..drop statements,” and disadvantages: “I can overwrite a proc without even knowing it.” Of course, the commenters have opinions of their own, and the piece becomes a straw poll for the desirability of that syntax as a feature.

Aaron Bertrand has one too: when was my database/table last accessed? Writes Aaron, “SQL Server does not track this information for you. SELECT triggers still do not exist. Third party tools are expensive and can incur unexpected overhead. And people continue to be reluctant or unable to constrain table access via stored procedures, which could otherwise perform simple logging.” He looks at 2008’s built-in auditing, and for those who can’t wait for that, illustrates a workaround for 2005.

Linchi Shea explores something else from 2008, Page Compression, focusing on how the number of processors affects the rebuilding a table with page compression.

Jamie Thomson, the SSIS Junkie writes that he has made a submission to Connect on the matter of absolute and relative paths in SSIS. “. . . I have always agreed that stipulating the use of absolute paths within SSIS was the right thing to do (and indeed I have championed it) however of late I have changed my mind. Support for relative paths would greatly simplify package deployment and package management . . . What do you think? Should SSIS support relative paths?” So far, it looks like a shoo-in.

Brian Knight also explains another little quirk, SSIS Case Sensitivity: “The case sensitivity can in some cases create behavior that is not expected and may give you bad results if you’re not careful.  . . . One such example is with the Lookup Transform, where comparisons against the cache are case sensitive. If you do not expect this, you may have a miss in a match that is actually a hit.”

In the MySQL ’sphere this week, there is plenty of talk about the openness or otherwise of MySQL. Read the rest of this entry . . .

Welcome, readers, to the 92^nd Log Buffer, the weekly review of database blogs.

Brian “Krow” Aker started an interesting blog-thread with his post, The Death of Read Replication, the crux of which is that object caches, such as memcached, make the DBMS itself a little less central, particularly in “Web 2.0″ scenarios. “What does this mean? Less database servers. Bringing down your load means you push off the load to another tier. . . . Why do I need to go through MySQL at all… unless I just want it as a backup or for ad-hoc reporting?”

Ronald Bradford responds with an overview of the MySQL-plus-replication scene. Farhan Mashraqi concurred with Brian’s post, while Arjen also agrees, adding, “I’m not sure the new memory based MySQL storage engines coming out are so relevant, they might be fixing the wrong thing in the wrong place.”

Ronald (who, by the way, is on-deck for a his third Log Buffer on the 25^th) also surveys both the storage-engine stuff to be had at the MySQL Conference, and the prevalence lately of talk about Kickfire in MySQL blogs, something also mentioned by Peter Zaitsev on the MySQL Performance Blog.

Peter has another question on his mind: should you have your swap file enabled while running MySQL? He wants to hear your approach to this matter, having himself experienced variable results. Lots of responses already.

Here on the Pythian Group Blog, Paul Moen posted about a situation in which SHOW SLAVE STATUS lies.

Moving into Oracle stuff, our Alex Gorbachev also pointed out something that doesn’t quite work: the ASMCMD cp command in ASM 11g. He sure gives it a try, but finally concludes: “I couldn’t make the cp command work even a single time.” Except maybe on datafiles.

Read the rest of this entry . . .

Welcome to the 89^th edition of Log Buffer, the weekly review of database blogs.

Welcome, welcome everyone.

In writing this week’s Log Buffer, I’ve had a chance to sit down and read some excellent posts on all sorts of platforms. The depth and breadth of what’s available to house and retrieve data is astonishing.

Many of you who have read my posts will know that I’m a fan of vegetables. They are something most of us don’t eat enough of. Come on DBAs! I think we need to make a collective effort to get healthy. We need you to keep all these systems alive. I say this because I have a new found appreciation for the work we do day in and day out.

Six months ago my wife and I said hello to our baby girl for the first time. I don’t say this to elicit any type of congratulations, but to illustrate something entirely different. If you have ever been to a hospital for any reason — to celebrate, to hope, or to say goodbye — you know the sheer complexity of the vast numbers of systems that need to interact. Daily, these systems save lives and help bring new ones to this world. I saw first-hand how the work I do on a everyday keeps the wheels turning.

Some of our customers run systems used by hospitals and I saw them in action. In a simple world, treating people can be done without technology, but this is an issue of scale, and our involvement directly affects the sheer masses of people whose lives are better because of our behind-the-scenes support. It’s true here, and it’s true for the most serious, most mission-critical systems, to the least critical and most trivial systems. The work done by DBAs from all platforms should be recognized for what it is.

I’m proud of what I do for a living and happy that I get to work in an industry filled with so many savvy folks. Oracle, Microsoft, MySQL, Postgres, IBM, and countless other organizations, and the people involved in them have together created an industry filled with opportunities and challenges, and above all, they have together elevated our ability to communicate and share. It’s in this spirit that Log Buffer was created, so let us proceed!

Since I’m an Oracle guy, we’ll let Oracle go first this time.

Read the rest of this entry . . .