Log Buffer #139: A Carnival of the Vanities for DBAs

Welcome to the 139^th edition of Log Buffer, the weekly review of database blogs. Let us begin with a look at the best from the Oracle ‘sphere.

Oracle

Many of you might be considering some more training or certification. Coskan Gundogar has already been there, and has returned with the tale to tell, What I learned during Oracle SQL Expert Exam Study Part-1.

In Jared Still’s Ramblings a discussion of the evils of encoding meaning into data.

Eric S. Emrick asserts that low cardinality != bitmap index.

On Oracle related stuff, Randolf Geist begins a series on partion oddities with an item on a severe bug in 10.2.0.4 patch set.

In his post on dynamic database link, Laurent Schneider asks and answers the question, “How do I select thru a database link, where the database link is not fixed?”

MySQL

Baron Schwartz of xaprb provides a handy segue, in the form of his article, 50 things to know before migrating Oracle to MySQL. “A while back I was at a seminar on migrating database applications to MySQL. A lot of the attendees were Oracle users.” (Are you reading this, Larry?) “Based on their questions, comments and conversations during lunch, I made the following list of things Oracle users need to know about migrating to MySQL.  . . .  1. Subqueries are poorly optimized.  . . .  2. Complex queries are a weak point.  . . .” (Are you reading this, Jonathan?)

Baron also discusses making Maatkit more Open Source one step at a time (Maatkit is Baron’s highly-rated toolkit for MySQL.)

On Information is contagious, the question is asked, why can’t you use subqueries on temp tables? The author finds a kind of answer in the source code. A reader asks, “Is this a minor implementation detail, or some kind of major conceptual issue?”

On MySQL’s blogs, Amit Saha has an excellent piece on getting started with DTracing MySQL. In case you don’t know, “DTrace is a dynamic tracing facility built into the Solaris and Open Solaris operating systems and can be used by system administrators and developers alike to observe the runtime behavior of user level programs and of the operating system itself.” (It’s also ardently wished-for by admins of Linux and other UNIX-likes.)

Mark Callaghan of High Availability MySQL says that, when it comes to adding to MySQL, global transaction IDs are hot, and they are part of a patch from Google that’s in the offing.

Paul McCullagh of the PrimeBase XT storage engine reports on improving PBXT DBT2 performance. He writes, “InnoDB has been extensively optimized for DBT2, and it shows.  . . .  DBT2 performance of PBXT is now more or less on par with InnoDB for memory bound tests.”

SQL Server

Arnie Rowland wants to know, is it time for SQL Server to have isolated transactions? Well, Arnie argues for it. He also says that your help is needed: “In order to best prepare and lobby for such a suggested ‘improvement’, it is important to have a clear understanding of the use case scenarios that we are attempting to solve with the isolated transactions.  . . .  So I ask you, if you see benefit from having an ISOLATED TRANSACTION in SQL Server, what is your use case? How would you use it? What are the pitfalls?”

Many SQL DBAs are excited about news of SQL Data Services (SDS). A lot of bloggers pointed to David Robinson’s article on the SQL Data Services Team Blog, entitled The no spin details on the new SDS features as the best source of info about this.

Please note that Brian Donahue does not approve of SSIS. Here here explains: Why I’ll Never Use SSIS (Unless My Family is Threatened), enumerating just why not. He finds some sympathy from his readers.

I suppose Jamie Thompson would argue otherwise, for as the SSIS Junkie, he must use it regularly. In any case, here he is on formatting T-SQL, his response to Simon Sabin’s post, Where should the ON clause go?

From Thinking outside the box, here is a highly rated T-SQL recipe to extract XML structure automatically.

PostgreSQL

Pavel Stehule previews some experimental psql, some face-lifting that will appear in 8.4 in the form of “epsql”.

Josh Berkus peers into his Database Soup and asks, What happened to Hot Standby? He writes, “By now, the news that Hot Standby won’t make it into 8.4 has rippled through the PostgreSQL community. A lot of people are asking me what happened,” following thatt with the explanation

On Just a Theory, David Wheeler and his readers have some answers to the question, why test databases?

DB2

Craig Mullins, on his DB2PORTAL Blog, offers “a friendly reminder to the DB2 community that the North American IDUG conference is fast approaching,” with a bit of preview of what you can expect if you do go.

That’s all for now. I hope you’ve enjoyed this edition. Don’t forget to add your favourite DB blogs from this week to the comments, or step up to publish an edition of Log Buffer on your own blog—just send me an email.