Log Buffer #167: A Carnival of the Vanities for DBAs

Posted in: Technical Track

Welcome to the 167th edition of Log Buffer, the weekly review of database blogs.

Since all that OOW news forced Gerry to give them short shrift last week, let’s begin with blogs on . . .

SQL Server

Jeremiah Peschka gets our week going with his refresher introduction to SQL Server system databases.

Likewise, Pinal Dave reviews the difference between candidate keys and primary key.

Mladen Prajdic says, “Ladies and gentlemen, boys and girls, the STP is back to rock your world!” Why? Because SSMS Tools Pack 1.7 is out with a new feature: SQL Snippets.

Michael Swart, The Database Whisperer followed up, and reports SQL Snippets is my new favourite thing.

Martin Bell was also gettin’ good and GUI. He shares his tips on how to display long text in SSMS.

Home of the Scary DBA also exposes some snags with Profiler GUI.

In general, when you hit snags, the question that arises, says The Rambling DBA, Jonathan Kehayias, is Have you got air in your spare tire? (Have you checked your DR/HA plans?).


Let’s start our look at MySQL blogs with a trivia challenge, courtesy Arjen Lentz: identify this query profile. “You do SHOW PROCESSLIST, and you see one of your web apps issue the following query: SELECT … WHERE … AND 1=2 UNION SELECT … What does this tell you, and what do you do next?”

Also, identify this replication failure.

Baron Schwartz also has a question for you, what do the InnoDB insert buffer statistics mean?:

Ever seen this in SHOW INNODB STATUS and wondered what it means?
Ibuf: size 1, free list len 4634, seg size 4636,

Baron has a review of The Art of Capacity Planning by John Allspaw, too.

Dave Stokes has a related offer: Want to know how Yahoo does their capacity planning? “Well, if you are in the Dallas / Fort Worth area on Monday, November 2nd you can find out exactly how they do it!  . . .  Strategic MySQL Planning for Complexity & Growth (i.e. MySQL Scaling for Dummies) will be presented by Tommy Falgout at the North Texas MySQL Users Group Meeting.”

Roland Bouman reports, Calpont opens up: InfiniDB Open Source Analytical Database (based on MySQL), beginning, “Open source business intelligence and data warehousing are on the rise!  . . . Calpont has just released InfiniDB, a GPLv2 open source version of its analytical database offering, which is based on the MySQL server.”

On the MySQL Performance Blog, Vadim examines Galera – synchronous replication for InnoDB.

On the Pythian blog, Sheeri Cabral shared a brief survey of large data sets and their hardware stats in MySQL and hardware information.


On Irrelevant thoughts of an oracle DBA, Freek D’Hooge gives us the unwelcome reminder that it’s (nearly) wintertime (again), in the northern hemisphere, at least. And with the season comes Standard Time. Freek writes, “In this post I would like to investigate how the session timezone settings affect the sysdate, current_date, systimestamp and current_timestamp variables during the switchover to or from daylight saving time.  . . .  A long running session is sufficient to pollute your data, certainly if you are using current_date as it has no timezone information.”

Richard Foote and his readers discuss another time-based ritual of old, rebuilding indexes every sunday afternoon. “I just had to share this amusing article on ‘Scheduling Oracle Index Rebuilding’.  . . .  if you’re like me and now work on sites where there is no such Sunday maintainance window because your users actually require and demand 24 x 7 access to their applications, because organisations still want to sell their products and services online during Sunday afternoons  . . .  etc. etc. etc. . . .  then perhaps the article may not be that useful to you afterall.”

The Oracle Instructor, Uwe Hesse, looks into “Total Recall”: Brief introduction into Flashback Data Archive. Writes Uwe, “With Oracle Database 11g, we have a new Option available, called Total Recall. This option extends the possibility to do Flashback Query, introduced in 9i already.  . . .  We can now designate particular tables for being able to track back all the changes on them even after years.”

Miladin Modrakovic, meanwhile, lays out the basics of ORION (Oracle I/O Calibration Tool) included in 11g R2.

Martin Widlake illustrates that partitions are not for performance: “There is a myth that Partitions in Oracle magically aid performance, even a general assumption that the main role of partitioning is to aid performance.  . . .  The myth is so strong that when asked at interview, most DBAs {and even some performance specialists} will site performance as the main (and occasionally only) benefit of partitioning.”

Chet Justice could sure use an interview. He is billing himself as a free Oracle developer/dba: “There is a serious lack of work in the Tampa market and desperate times call for desperate measures.  . . .  Now, I’ve always wanted to do this, but was never in a position to do so financially…I’m still not, but something is way better than nothing.  . . .  I’m going to offer my services for free.”


Josh Berkus tells Postgres admins, Alpha2 is out, and we need YOU to test it. “Version 8.5, alpha 2 is now out and available for your download. This means that you get a nice present: a preview of 8.5’s features for your entertainment, interest, and application design. Try the new features now! Of course, this places an obligation on you as well; to test the alpha, and let us know about the bugs.”

Pavel Stehule is on the case. Here he introduces named function parameters – a feature of PostgreSQL 8.5.

On select * from depesz;, Hubert Lubacziewski explains calculating backlog of events. The problem: “We have a system which, every 5 minutes, takes a number of tasks to be done. Tasks are uniform. Within 5 minutes we can handle at most 100 tasks. Given the history of number of tasks added every 5 minutes, calculate backlog at any given moment.”

Ropert Kalmar brings the news of EnterpriseDB + Red Hat “This press release from Reuters,” he writes, “about Red Hat investing in EnterpriseDB is great news. Since Red Hat once manage to bring Linux to the room of Enterprise IT I’m hoping this would increase the acceptance of PostgreSQL adoption in the Enterprise world.”

That’s it for now. Thank you for tuning in, and please leave a link to your favourite DB blog from this week in the comments. See you in a week!

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About the Author

Dave Edwards is the Communications Specialist for the Pythian Group.

4 Comments. Leave new

Sheeri Cabral
October 30, 2009 3:08 pm

And this week in Drizzle:

Replication, replication, replication!

Jay Pipes describes Drizzle Replication Changes in API to Support Group Commit, continuing to explain how the messaging system works. Jay also explains Drizzle Replication, The Transaction Log. Replication from MySQL to Drizzle using Tungsten Replicator is now possible thanks to Marcus Eriksson.

David Edwards
February 2, 2010 4:14 pm

Thanks, Sheeri.


Great post I really clicked all the links.

Good work.

David Edwards
February 2, 2010 4:15 pm

Many thanks, Pinal, that’s so nice to hear.


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