This is the 176th edition of Log Buffer, the weekly review of database blogs.

There were heaps of mostly technical posts this week. I think bloggers are tired of kicking around the ins-and-outs of Sun and Oracle, and wanted to talk about what really matters. So let’s start with . . .

Oracle

Harald van Breederode shows how to setup a private DNS for your virtual cluster.

Pythian’s Alex Fatkulin discusses Oracle GoldenGate …

Release 1.2.2 of Tungsten Clustering is available on SourceForge as well as through the Continuent website.  The release contains mostly bug fixes in the open source version but there are also two very significant improvements of interest to all users.

• The manager and monitoring capabilities of Tungsten are completely integrated on the same group communications channel.  This fixes a number of problems that caused data sources not to show up properly in older versions.  
• We are officially supporting a new Tungsten Connector capability for MySQL called pass-through mode, which allows us to proxy connections by transferring network blocks directly rather than translating native request protocol to JDBC calls.  Our tests show that it speeds up throughput by as much as 200% …

WordPress Foundation formed. Reaction to Oracle-Sun approval. And more.

WordPress Foundation formed
# Matt Mullenwag launched the WordPress Foundation.

Reaction to Oracle-Sun’s EC approval
# In a memo Sun CEO Jonathan Schwartz encouraged the company’s employees to emotionally resign from Sun.

# EnterpriseDB and PostgreSQL co-founder Bruce Momjian issued a statement on the EC’s decision to approve Oracle-Sun.

# Mike Hogan …

I’d like an UNTIL clause, please. I’d use it sort of like LIMIT in MySQL and PostgreSQL, except that it would define when to stop returning looking for rows, instead of defining how many to return. Example:

SELECT * FROM users ORDER BY user_id UNTIL user_id >= 100;

That would select users up to and including user 99. Ideally the clause could accept any boolean predicate, including subqueries. I’ll hold my breath and wait for this wish to come true now.

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Welcome to the 175th edition of Log Buffer, the weekly review of database blogs.

Oracle

Let’s begin with remoteDBAexperts blog, and Chris Foot’s prediction of the future of database tuning and database administration. It will be, ” . . . administrators interpreting and implementing the recommendations generated by the intelligent advisors and ADDM.  . . .  I also think that Oracle will eventually become self-tuning.”

Here in the present, DBAs (Oracle and otherwise) are still Striving for Optimal Performance as Christian Antognini is. Here’s his item on join …

I began porting the dba module to Drupal 7 as an opportunity to learn more about the new database abstraction layer. In this upcoming Drupal release, our database layer is now built upon the PHP Data Objects (PDO) data-access abstraction layer, introducing new syntax and symantecs into writing queries with Drupal. A powerful new query builder makes it possible to easily write queries that run on any database type supported by Drupal, currently including MySQL, PostgreSQL and SQLite.

The dba module was always intended to be a useful tool for any database administrator, and toward that end I have recently merged in mysqlreport functionality which utilizes MySQL's server statistics to offer an overview of server health and performance. As an …

iostat is one of the most important tools for measuring disk performance, which of course is very relevant for database administrators, whether your chosen database is Postgres, MySQL, Oracle, or anything else that runs on GNU/Linux. Have you ever wondered where statistics like await (average wait for the request to complete) come from? If you look at the disk statistics the Linux kernel makes available through files such as /proc/diskstats, you won’t see await there. How does iostat compute await? For that matter, how does it compute the average queue size, service time, and utilization? This blog post will show you how that’s computed.

First, let’s look at the fields in /proc/diskstats. The order and location varies between kernels, but the following applies to 2.6 kernels. For reads and writes, the file contains the number of …

This tweet from former MySQL AB CEO Mårten Mickos caught my eye. It shows a trend of increased demand for MySQL and PostgresSQL expertise while job postings on job websites for  those with Oracle and Ingres expertise declined.

I was a little shocked by the graph until you realize it’s just a trend. I then looked at the absolute number of jobs requesting database expertise and the story quickly becomes clear….

…

Software-as-a-Service (Saas) is one of the main growth areas in modern database applications.  This topic has become a correspondingly important focus for Tungsten, not least of all because new SaaS applications make heavy use of open source databases like MySQL and PostgreSQL that Tungsten supports.

This blog article introduces a series of essays on database architectures for SaaS and how we are adapting Tungsten to enable them more easily.  I plan to focus especially on problems of replication and clustering relevant to SaaS—what are the problems, what are the common design patterns to solve them, and how to deploy and operate the solutions. I will also discuss how to make replication and clustering work better for these cases—either using Tungsten features that already exist or features we are designing.

I hope everything you read will …

It’s New Year’s Eve, a date that should strike terror into the hearts of many, because tomorrow a bunch of their queries are going to fail.

Queries to “find all birthdays in the next week” and similar are always a nightmare to write. If you want to see a bunch of examples, go look at the user-contributed comments on the MySQL date and time function reference. This post is about a slightly saner way to do that. There’s still some nasty math involved, but a) a lot less of it, and b) at least the query will be able to use indexes[1].

So here’s my tip: instead of storing the user’s full birthdate, just store the month and day they were born. Try it. You’ll love it!

[1] Yes, I know Postgres can index a function. So this can be considered a jab at MySQL, which can’t.

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