Pythian Group

Warm welcome to the Log Buffer, a weekly amalgamation of database news across different technologies. Let’s get warmed up with sizzling Log Buffer #213.

Oracle:
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One of the leading performance gurus, Kellyn Pederson is letting us know how she is finding the initial months at Pythian and she rightly praises her fabulous team mates Mark Brinsmead, Paul Logan, and Andy Klock.

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Welcome to Log Buffer, the weekly news update of happenings in the database world.

A big shout out to Pythian team members Andrey, Gwen, Fahd, and Don for their submissions. We have lots of news and recommended reading this week so let’s get going with Log Buffer #209.

Andrey Goryunov’s top picks:
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A very warm welcome to the Log Buffer, the premier medley of fresh information culled from the blogs related to the technology which stores the world, yes, the databases.

In this edition, the Log Buffer #205, we have yet again found the pulse of the industry.

Oracle:

On the Oracle front, leading Oracle technologist Andrey Goryunov carries on his hands-on experiments of newest version of the Oracle database. This time he slices away chopt.

It’s always very informative and exciting to know about internals of RAC Stuff like what actually is maintained in the Voting Disk . Riyaj has it here.

Jonathan Lewis does a little thought experiment with list partitioning.

HugesPages almost always provide value to the Oracle databases on the Linux Systems, and many people wonder why they are not the default. Kevin Closson touches some points regarding HugesPages, and he also notes down some finer points like the dislike of AMM and Hugespage for each other.

Hardly anyone would refuse a gift consisting of chocolate, ice cream, flower and designer watch. Yes, now you can have Tanel Poder, Cary Millsap, Jonathan Lewis, and Kerry Osborne at one Virtual Oracle Conference.

Tim Hall, like many other people is perturbed over the plagiarism of his articles.

Oracle recommends that you use JRockit JDK with your Oracle products and the reasons are described by JaySenSharma at his Weblogic Wonder blog.

DB2:

Now, RPM and DEB packages for DB2 Express-C are available for the download. Get it from here.

Troy Coleman, blogs about the ripple-creating news that Last week IBM announced the general availability of DB2 10 for z/OS.

The keynote session for the third day of the IOD conference features the authors of Freakonomics, Steven Levitt and Stephen Dubner, and Craig Mullins highly recommend that.

SQL Server:

If you are curious about the title “Plumbing The Depths of SQL Server / PowerShell Integration, then don’t miss SQL Server Connections conference on Nov 1-4 in Las Vegas and attend the session by Bob Beauchemin.

Though not earth-shattering and sky-ripping, but very valuable nonetheless this post by Jeff about calculating the median.

And following is the ever-green SQL Server Myth buster posts by Euan.

MySQL:

Zack Urlocker rambles on how open source software, cloud and software as a service are helping to bring about the consumerization of IT.

Here is one more effort where the bencmarking of MariaDB is being done.

Have a nice weekend.

Welcome to Log Buffer, the weekly roundup of happenings in the database world.

Lots to cover this week, so let’s get on with Log Buffer #204. Enjoy!

Oracle:

Pythian’s Gwen Shapira dabbles with MySQL and explores MySQL troubleshooting for the Oracle DBA.

Venkat Janakiraman explores how connectivity works for BI EE 11g on Microsoft SQL Server Analysis Services 2008.

Iggy Fernandez explores SQL 101: Which Query is better, in part II to a post he covered in summer of this year.

Chet Justice, on Oraclenerd reviews how to use forgotten function OBIEE: Evaluate

Tanel Poder announces last chance for early-bird rates to sign up for the virtual conference on Systemic Oracle SQL Optimization featuring himself, Cary Millsap, Jonathan Lewis & Kerry Osbourne.

DB2:

Lots going on at the IOD 2010 conference over the past week. Craig Mullins covers the event with news, a video of attendees, and the final keynote.

MySQL:

Sheeri Cabral shares how she determines MySQL fragmentation.

Baron Schwartz posts the third in a series of posts on MySQL limitations – one thread per connection. In case you missed them, part 1 covered single-threaded replication, part 2, the binary log, and part 3, subqueries.

SQL Server:

On In Recovery, Paul S. Randal invites readers to participate in a survey to determine wait times on systems. Chime in with your feedback by commenting on his blog post or sending him an email after reading the instructions. Paul is also calling for participants for T-SQL Tuesday #12 – Why are DBA skills necessary.

And lastly in Postgres news, PG West 2010 is happening next week. There are a number of posts on the need for replication in PostgreSQL 9.0. Joshua Drake stirred the pot, responded and created a Replication poll to find out what you really think. Cast your vote!

Happy Haunting weekend.

This is the 182nd edition of Log Buffer, the weekly review of database blogs. Make sure to read the whole edition so you do not miss where to submit your SQL limerick!

This week started out with me posting about International Women’s Day, and has me personally attending Confoo (Montreal) which is an excellent conference I hope to return to next year. I learned a lot from confoo, especially the blending nosql and sql session I attended.

This week was also the Hotsos Symposium. Doug’s Oracle Blog has a series of posts about Hotsos. If all this talk about conferences has gotten you excited, Joshua Drake notes that 14 days and the hotel is almost full for postgresql conference east which is March 25th-28th in Philadelphia. And the Oracle database insider notes that the Oracle OpenWorld call for papers is now open.

According to Susan Visser this week (ending tomorrow) is also read an e-book week. So if you have not already done so, read an e-book! She links a coupon for an e-book in the post.
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Welcome to the 160^th edition of Log Buffer, the weekly review of database blogs.

MySQL

Blame it on MyISAM, says Mark Callaghan of High Availability MySQL, on considering sql_mode and type coercion. “I think that MyISAM has its place,” writes Mark. “It does fast table scans, but InnoDB is much faster on just about everything else. I am just not thrilled with the impact it has had on MySQL.”

Not that those other engines are without flaw. Peter Zaitsev reports on an InnoDB performance gotcha with larger queries.

Here on the Pythian Blog, Singer Wang unearthed a MySQL 5.1 and InnoDB hot backup gotcha.

Eric Bergen offers his InnoDB deadlock count patch, which he introduces thus: “[Deadlocks] usually aren’t a problem until they start happening too frequently.  . . .  [SHOW ENGINE INNODB STATUS] can be useful for debugging but it’s almost impossible to get the rate at which deadlocks are occurring. [This patch] adds a counter to show table status that tracks the number of deadlocks.”

Baron Schwartz had a script snippet to relative-ize numbers embedded in text to share. Read the rest of this entry . . .

This is the 158^th edition of Log Buffer, the weekly review of database blogs.

SQL Server

Simon Sabin has a TSQL Challenge – counting non zero columns. He says, “I’m working on a project where I need to cycle a flag amongst a set of columns. To achieve this I am storing a position value in each column which allows me to cycle them . . .  So the challenge is to find out the how many non zero columns there are, the twist is to use as little code as possible.”

On a cue from Simon, Aaron Bertrand shares a quick experiment in Unicode Compression on SQL Server 2008 R2. “ . . . what is going to happen.” Aaron writes, “is that NCHAR / NVARCHAR . . . columns, in objects that are row- or page-compressed, can benefit from additional compression, where realistically you can cut your storage requirements in half, depending on the language / character sets in use.  . . .  The difference is astounding: a space savings of roughly 60%, FOR FREE.”

Kimberly L. Tripp is here to tell us, Column order doesn’t matter… generally, but – IT DEPENDS! “SQL Server doesn’t care about the order in which you define the columns of your table because internally SQL Server will re-arrange your columns to store all of the fixed width columns first and the variable columns last.  . . .  It’s all in the cost of the variable array’s offset values.”

Joe Webb of WebbTech Solutions exposes some some not-so-obvious side-effects UNION in a SQL query.

Aaron Alton, The HOBT, informs us that the Transact-SQL OVER clause is not just for ranking functions. “Prior to the OVER clause, we would have needed to create a derived table which GROUPed the query by our partition columns, then joined said table back to our parent query. This method is much cleaner, and much more efficient . . . ”

Jason “Hutch” Massie blows his cover by revealing his secrets of SQL Server consultant. (Well, not really, but the badge is kind of a giveaway.) Jason writes, “Well, I hope you are not looking for them from me. All of my secrets are common knowledge now. I was hoping you would share yours with us. Just leave them in the comments. I promise not to tell anyone. They can be our little secret, dawg.”

MySQL

On the MySQL Performance Blog, Morgan Tocker explains why you don’t want to shard. (It has nothing to do with The Dark Crystal, I already checked.) A good post—lots of debate and discussion.

You don’t want to shard, but you might want a slice of SQL pie—Shlomi Noach’s SQL-generated pie chart, that is.

Jayant Kumar provides a nice backgrounder on document oriented data stores, and compares some examples—TokyoTyrant, MongoDb, and CouchDb—to MySQL 5.4.

Let’s go back to Morgan Tocker for a moment, and his post helping everyone in understanding the MySQL forks, complete with a handy family tree. Thank you, Morgan.

Mark Callaghan of High Availability MySQL has found a reason to use 5.1: “I can reduce the size of the patch I need to maintain extreme performance with MySQL.” Mark also has some remarks on four new features from InnoDB, Percona, and Google.

Oracle

Jonathan Lewis writes, “Here’s a thought for the weekend . . . ” When people talk about ‘index fragmentation’, what do they mean, and why do they care?  . . . ”would you let me know what you mean, and how you measure [it]. (I can think of three or four interpretations for the term – but I’m interested to hear from people who actually use it.)”

On So Many Oracle Manuals, So Little Time, Iggy Fernandez shares Great Expectations: An Interview with Tanel Poder, covering, among other subjects, Tanel’s background, Oracle ACE and certification, and OSs.

Let’s stay with Iggy for The Tenth Solution—that is, his own solution to the NoCOUG Challenge.

Here’s Alex Fatkulin demonstrating how to install Oracle Grid Control agents on a Windows failover cluster with no downtime.

On Striving for Optimal Performance, Christian Antognini discusses 11g’s improvements to system managed extent size.

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Welcome to the 157^th edition of Log Buffer, the weekly, cross-platform review of database blogs.

SQL Server

We start with Michelle Ufford, the SQL Fool, who gives us the poor (wo)man’s graph, a fast and ingenious way to create handsome text-based graphs.

What is the importance of running regular consistency checks? Paul S. Randal returns with some survey results and analysis. He writes, “The results are actually surprising – I didn’t expect so many people to be running consistency checks so frequently . . . ”

On SQLblog.com, Aaron Bertrand offers his nuanced approach to processing a list of integers. Aaron points to some other approaches; and his readers kick it around.

Jonathan Kehayias appears this week with with a rant: Got Performance Problems? Buy bigger hardware!. “ . . . The title of this thread is very tongue in cheek . . .  However, it is the most common answer I seem to get from application vendors these days when dealing with performance issues, despite the fact that I can point out a dozen reasons why their application design/code is the problem.  . . .  How does this relate to SQL Server? Read the rest of this entry . . .

Welcome to the 154^th edition of Log Buffer, the weekly review of database blogs. Let’s dive right in, shall we?

Oracle

On Radio Free Tooting, Andrew Clarke says, “No SQL, so what?” taking as his keynote something Nuno Souto said: “ . . . Google, Facebook, Myspace, Ning etcetc, and what they do as far as IT goes, are absolutely and totally irrelevant to the VAST majority of enterprise business.”

Aman Sharma gives an overview of Library Cache on Arista’s Oracle Blog.

On The Dutch Prutser’s Blog, Harald van Breederode gives a lesson in rolling cursor invalidation. He writes, “ . . . I call DBMS_STATS to create a histogram and I expected that dependent cursors would be marked INVALID afterwards but this simply didn’t happen.  . . .  Somehow I forgot, or maybe completely missed, the fact that cursors are invalidated in a rolling fashion since the introduction of Oracle10g.”

Miladin Modrakovic looks into another 10g-ish thing—Wide Table Select (Row Shipping): “Row shipping is feature which allows row data from the datablock to be shipped directly to the client.  . . .  Aperently [sic], this feature had some issues in earlier version of 10g and fix was to disable the ‘row shipping’ feature by default.Oracle introduced ‘fix’ in version 10.2 . . . ”

Dominic Brooks reports a gotcha in application contexts, “ . . . one of those feature behaviours which isn’t surprising, but you probably wouldn’t think about it unless you saw it.”

Who should tune SQL: the DBA or the developer? Read the rest of this entry . . .

This is the 153^rd edition of Log Buffer, the weekly review of database blogs.

Let’s start by revisiting a perennial issue with Craig Mullins addresses with the question, Are DBAs Obsolete? “Before we go any further, let me briefly answer the question posed in the title of this blog entry: ‘No Way!’,” writes Craig. “Every time I hear this it makes me shake my head sadly as I regard just how gullible IT publications can be.” He argues that an Internet-paced attitude regarding the work of the DBA may be the first culprit in the devaluation of the DBA’s work.

Oracle

Dion Cho, the Oracle Performance Storyteller, looked at attempting to get an object name from file# and block#, and, “ . . . met with a big disappointment on the performance.” And he found a promising workaround.

Laurent Schneider gave a lesson in how to select from a column-separated list.

Randolf Geist exposed the matter of dynamic sampling and set current_schema anomaly. “Sometimes when I’m asked to check a particular SQL in a production like environment at first I only get rather limited access, e.g. a read-only user . . .  If I’m now supposed to analyse a rather complex SQL with dozens of table and/or view references I like to use the ALTER SESSION SET CURRENT_SCHEMA command . . . but I recently have come across an interesting anomaly in 10.2.0.4 . . . ”

How many bind variables is too many, asks Kerry Osborne. (How about, as an arbitrary limit, when scrolling the output of a SELECT statement causes seizures?)

Here on the Pythian Blog, Alisher Yuldashev published his HOWTO on performing a manual Oracle 11g SE switch-over.

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