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Log Buffer #118: a Carnival of the Vanities for DBAs

By David Edwards October 10th, 2008 at 11:01 am
Posted in Log BufferMySQLNon-Tech ArticlesOraclePostgreSQLSQL Server
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The 118th edition of Log Buffer, the weekly review of database blogs, has been published on Ward Pond’s SQL Server blog.

Log Buffer is the only platform-neutral, distributed, human-edited article on database blogs. It receives several thousand views each week, and publishing an edition on your own blog brings those views to you. Hosting an edition of LB also introduces you and your blog to your colleagues in the DB blogosphere. Write me an email and I’ll get you started.

Now, here’s Ward Pond’s Log Buffer #118.

Log Buffer #116: A Carnival of the Vanities for DBAs

By David Edwards September 26th, 2008 at 11:51 am
Posted in Log BufferMySQLNon-Tech ArticlesOraclePostgreSQLSQL Server
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Welcome to the 116th 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 blogThe 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!

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Log Buffer #115: A Carnival of the Vanities for DBAs

By David Edwards September 19th, 2008 at 11:45 am
Posted in Log BufferMySQLNon-Tech ArticlesOraclePostgreSQLSQL Server
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Welcome to the 115th edition of Log Buffer, the weekly review of database blogs.

I must thank Paul for taking over at last minute for LB#114 last week, when, as he put it, “ . . . a killer combo of painkillers and the pain that the painkillers can’t kill . . . ” reduced to me a less-than Log-Buffer-capable state. Or to be more precise, to a writhing, benighted gargoyle of misery. (Too colorful?)

Anyway, the good news is that I’m better. Not all better, mind you. Between the tooth thing and my spending all my working time on a special project, there was nothing left for poor old Log Buffer. So, I face the choice: throw it open to you, LB’s loyal readers for your contributions; or adopt Paul’s approach1 from last week, and use the nifty AideRSS.

I’m going to bet on our readers. Let’s hear from you with your picks for best database blogs of the week gone by. I promise you a real, proper Log Buffer next week, from someone. If not me, well, Nick Westerlund still wants his go, and Ward Pond is back looking for a slot.

Until then, wish me luck with my angry tooth.

1. The truth is that I was briefly worried about having my job taken away by software. My concerns were allayed, at least partially, when I saw that the original software-built list of database blogs also included an item from “manscaping.com”, which I’m fairly sure had little or nothing to do with database administration.

Log Buffer #113: A Carnival of the Vanities for DBAs

By David Edwards September 5th, 2008 at 11:49 am
Posted in Log BufferMySQLNon-Tech ArticlesOraclePostgreSQLSQL Server
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This is the 113th edition of Log Buffer, the weekly review of database blogs.

Sheeri Cabral gets things going this week with her coverage of this rumour: Monty Widenius Leaves Sun/MySQL. If it turns out to be true, that seems like bad–or at least sad–news for MySQL, but Sheeri’s take is mostly an optimistic one.

MySQL’s Kaj Arno responds to the rumours on Monty resigning: “First, it’s a rumour.  . . .  Second, Monty’s resignation has been a possible outcome already since years before the Sun acquisition.  . . .  I can neither confirm nor deny the rumour.”

On CNET’s The Open Road, Matt Asay says. “Monty has done the right thing with his dissent. He has taken it outside the company, as Arjen Lentz, MySQL’s twenty-fifth employee, did before him. Arjen continues to be both a promoter and critic of MySQL, but is able to do so publicly without the constraints of an employee agreement. I assume Monty will do the same, and rightly so.” That’s not all the response out there, and there will certainly be still more as this develops.

In non-Monty blogs, Brook Johnson of Database Science asks, can a timestamp be slower than a datetime? (more…)

Log Buffer #112: A Carnival of the Vanities for DBAs

By David Edwards August 29th, 2008 at 11:48 am
Posted in Log BufferMySQLNon-Tech ArticlesOraclePostgreSQLSQL Server
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Welcome to the 112th edition of Log Buffer, the weekly review of database blogs.

First, thanks to last issue’s contributors–Joe Izenman, Dan Norris, and Jason Massie–for snatching victory from the jaws of defeat and making LB#111 a worthwhile read. That’s what it’s all about!

Oracle’s up first, starting with our old friend Doug Burns and his Time Matters series, in which he holds up to the light the concept of DB Time: “. . . [the] total time spent by user processes either actively working or actively waiting in a database call.” He continues, “There’s a lot more I could say about DB Time. Like all of the best performance concepts or methods (e.g. YAPP, Method-R) it can seem so obvious as to not be worth saying, but contains an enormous amount of common sense and technical rigour.”

Arup Nanda writes about the time he spent Diagnosing Library Cache Latch Contention. About half an hour, as it happened, but he’s a real pro, and his analysis just goes to show. To quote, Nuno Souto–who makes the best blog endorsements– “Damn useful stuff . . .  bookmarked.”

Tanel Poder has another script for you to fall in love with, which makes its debut in flexible sampling of any V$ or X$ view with sample.sql. It is, writes Tanel, “ . . . a simple but powerful sqlplus script for ad-hoc sampling of any V$ view.”

Kenneth Downs, the Database Programmer, offers Advanced Algorithm: Sequencing Dependencies, a smart look at satisfying dependencies in databases. What does that mean? Well for example, Kenneth writes, “All popular Linux distributions have a package installation system in which each package lists its required dependencies. If you want to install a large number of packages in one shot, producing a tangled bunch of related dependencies, today’s algorithm can be used to work them all out.”

That’s the kind of task for which we humans use tools like mind maps. Jason Arneil shares his ASM Mind Map.

Laurent Schneider went off-road and came back something not on the map at all: the difference between rollbac and rollback.

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Log Buffer #111: A Carnival of the Vanities for DBAs

By David Edwards August 22nd, 2008 at 11:13 am
Posted in Log BufferMySQLNon-Tech ArticlesOraclePostgreSQLSQL Server
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Crisis has struck! This week’s Log Buffer editor had to beg off at the eleventh hour when his time vanished. It happens. But, in every crisis, an opportunity (well . . .  maybe, maybe not). The opportunity — an open discussion of this week’s best database blog articles. Readers in control.

Log Buffer is always looking for editors, so if you’d like to step forward and publish one on your own blog, read the Log Buffer guidelines and send me an email.

I’m going to go through my bookmarks and add my own presently. I hope to hear from you!

Log Buffer #110: A Carnival of the Vanities for DBAs

By David Edwards August 15th, 2008 at 11:46 am
Posted in Log BufferMySQLOraclePostgreSQLSQL Server
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Welcome to the 110th edition of Log Buffer, the weekly review of database blogs.

From the MySQL side, Jeremy Zawodny gets things going this week. He writes about his doubts over the long-term performance of InnoDB, specifically the cost of multiversion concurrency control, particularly in a master-slave arrangment or a DW. Jeremy comments, “[The] disk bloat, fragmentation, and ongoing degradation in performance may be an argument for having some slaves that keep the same data in MyISAM tables.” His readers, however, point out some diagnostics and tools to remedy this concern.

Not that MyISAM is without foibles. Case in point, on the MySQL Performance Blog, Peter Zaitsev says, Beware of MyISAM Key Cache mutex contention. “. . . inserting in parallel into different tables when indexes fit in memory results in very bad contention causing hundreds of thousands of context switches per second with far less work done than one would hope.” Happily, as Peter reports, multiple key caches mitigates.

Peter also surveys the choices for picking a datatype for STATUS fields — “. . . ’new’, ‘confirmed’, ‘in production’, ’shipped’ status of job, message etc. People use variety of ways to handle them often without giving enough thought to the choice which can cause problems later.” VARCHAR(N), ENUM, TINYINT — which is right for the job?

Here on the Pythian Group Blog, Nicklas Westerlund demonstrates adding a unique constraint on a table with duplicate data.

Also here at home, Sheeri Cabral’s item on why you want to switch to MySQL 5.1. She argues that additions such as online ALTER TABLE, online table-based logging, and INFORMATION_SCHEMA.PROCESSLIST are compelling features worth an upgrade.

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Log Buffer #109: A Carnival of the Vanities for DBAs

By David Edwards August 8th, 2008 at 12:00 pm
Posted in Log BufferMySQLNon-Tech ArticlesOraclePostgreSQLSQL Server
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It’s time again for another edition of the weekly review of database blogs, Log Buffer. Since it was a big week for SQL Server, let’s start there, shall we?

The big news — SQL Server 2008 is released, as reported by SqlServer-qa.net, in seven different versions. Aaron Bertrand introduces a new kid on the block: SQL Server 2008 Web Edition — “. . . designed for highly available Internet facing web serving environments for the next generation Windows Server,” according to MS. (I’ve heard it rains quite a lot in Seattle. I guess it also Drizzles, too.) Says Aaron, “Basically, it has higher scalability than Express or Workgroup Editions : it supports up to 4 CPUs, no artificial limit on RAM, and unlimited database size.”

(Before you crack open your server case, Tara Kizer on Ramblings of a DBA has some advice on how to get physical CPU count on a server.)

The SQL Server Express Express blog helpfully offers a table outlining the differences in the features of the differences between SQL Server 2008 Express editions.

A couple little issues with the release have already emerged. Here’s Euan Garden on SQL Server 2008 Installation Confusion, VS 2008 Sp1 and NetFx 3.5 Sp1: “SQL Server 2008 has dependencies on (and includes) VS 2008 SP1 and its components (BIDS is just VS 2008, SSMS uses components), plus NetFx 3.5sp1. SQL includes the RTM versions of both of these, HOWEVER they are not broadly released yet. There is a check in SQL Server Setup that if you have an old version (Beta, RC, whatever) it will bounce the install and ask you to upgrade to the RTM bits…which of course are not yet available independent of SQL.” Click through for the KB and some other help. Denis Gobo and his readers have some more to say about this.

In all this change, you may lose sight of an important fact or two, and you may ask yourself, how did I get here . . . what version of SQL Server am I running? A couple resources are shared by Kevin Kline.

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Log Buffer #108: A Carnival of the Vanities for DBAs

By David Edwards August 1st, 2008 at 11:54 am
Posted in Log BufferMySQLOraclePostgreSQLSQL Server
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Welcome to the 108th edition of Log Buffer, the weekly review of database blogs.

With almost no ado at all, let’s begin with the bad news–from StatisticsIO and Jason Massie: The Death of the DBA. And who is the perpetrator of this crime? The Cloud! It sounds like something from a John Carpenter movie, doesn’t it?

Let’s see what Jason is thinking. “I’d like to retire a SQL Server DBA with 40 years experience but I don’t think that will happen. The cloud is coming and it is bad news administrators, database or otherwise.  . . . Let’s make some assumptions. The features get there. The availability gets there. The platform basically matures . . . Now put yourself in the IT decision maker’s shoes. No upfront capital expenses, no managing backups, and no patch management.  . . . If they can remove their focus from managing and deploying IT, they sell and service more widgets.”

Scary stuff, right? Well, the commenters don’t entirely agree. I think it will be at least a factor, but I wonder how many managers will look at “The Cloud” and feel uncomfortable about privacy, data retention, and the like. (For myself, I couldn’t even endorse the idea of putting this blog’s comments into “The Cloud”.) What do you think?

Elsewhere on StatisticsIO, Jason has a note about MSDN’s SQL Heroes contest, whose aim is to, “. . . create a community project in CodePlex based on SQL Server 2008.” Jason also links to a list of CodePlex’s active SQL Server projects.

Turning to matters technical, Jeff’s SQL Server Blog offers a lesson on converting input explicitly at your client: don’t rely on the database to “figure it out”. Jeff takes the example of formatting dates, and show both the right and the wrong way, writing, “I’ve said it over and over and I’ll say it again: The concept of formatting dates should never be something that your database code should ever worry about.”

On the Less Than Dot blog, SQLDenis observes that converting columns to date from datetime does not result in a scan in SQL Server 2008. What you get instead is a seek, as he demonstrates.

Indexing Foreign Keys - should SQL Server do that automatically? So asks Greg Low on the The Bit Bucket. “By adding indexes on the foreign keys on three tables,” he writes, “we saw a reduction of 87% in total I/O load.  . . . it really struck me that having SQL Server do this by default would avoid a lot of apparent performance problems.  . . .  Should SQL Server simply do this by default when you declare a foreign key reference?”

Kent Tegels of Enjoy Another Sandwich — riddle me this, riddle me that! “When is a bug not a bug?” I give up, Kent. When is a bug not a bug? (more…)

Log Buffer #104: a Carnival of the Vanities for DBAs

By David Edwards July 4th, 2008 at 11:15 am
Posted in Log BufferMySQLNon-Tech ArticlesOraclePostgreSQLSQL Server
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Andrew Clarke has published to 104th edition of Log Buffer, the weekly review of database blogs, on Radio Free Tooting, marking LB’s second year. Happy Birthday, LB!

Log Buffer always needs editors, so if you you’d like to present your view of the week that was in DB blogs, contact me, the Log Buffer coordinator. You’ll be joining some of the best bloggers around, and making yourself and your blog a little better known to readers around the world.

And now, here’s Andrew Clarke’s Log Buffer #104.

P.S.: To our readers in the U.S. — Happy 4th of July!