While working on a transformation I ran into a problem with
comparing two (seemingly) identical numbers using the Filter Rows
step. I had a case where a transformation selected two
DECIMAL(13,5) values from the database and compared them.
I could see that the numbers were identical in the MySQL
database, but the Filter Rows step returned false when comparing.
To troubleshoot, I tried multiplying the difference of the two
numbers by 10,000,000 ( in the transform) and I actually
discovered a very small difference beyond the 5th decimal place.
This datatype in MySQL is considered an "exact" datatype, not to
be confused with a FLOAT.
My solution is to convert the two fields to Strings and do the
comparison. If you don't like that, then explicitly round the
numbers using the Calculator step. The Select and Alter step,
doesn't seem to truncate the numbers and I don't think it was
intended to alter the raw data anyway.
…
I checked in in the speaker lounge and picked up my bag of shwag.
This year O'Reilly is giving speakers some free books, slide:ology and Confessions of a Public Speaker . It makes
sense for them to give these books to their speakers, as the
better the speakers are, the better the conference is, and the
more successful O'Reilly is at getting more conference
business.
I spent the first part of the day fielding scheduled calls with
members of the tech press about Gear6's …
From the MySQL keynote today by Edward Screven. The Oracle LAMP Stack is looking pretty impressive. The stack includes: - Oracle Enterprise Linux - Oracle VM (Xen-based) - Apache, Glassfish - MySQL - Java, PHP, Perl, Ruby, C, C++ More … Continue reading →
Yes, no kidding, I'll be wearing an old Oracle T-Shirt from my
days at Big-O in the 1980's. I was, and your Oracle dudes who has
been around for a while might remember these, an Oracle Unix
Wizard. Actually I was a Wizard II (I went to the second
training), but the T-Shirt I will be wearing is from Oracle Unix
Wizards I.
Where will this take place you ask, as you just HAVE to come?
Well, no further than my BoF tonite on the History on Databases. And I
can tell you, this is not a T-Shirt that I would normally wear in
public, but there is a lot of stuff I would do to attract a crowd
to a BoF (just to see everyone running away in disgust). So at
7:00 PM tonite, tuesday, in Ballroom C (unless the location
changes). Bring your good mood, ideas on the past and on the
future, and above all, your barf-bags, to see what an ""Oracle
Unix Wizard" looked …
PACKT Publishing sent me titled "MySQL Admin Cookbook" to review and I told
them that I would be brutally honest about it. They said cool and
well here, we go.
Overall, the book is cool if you are starting out in MySQL
administration and want to get a box up and running. If you are
looking to scale MySQL or make your application faster this is
not the book for you. If you are worried about consistency and
getting the most out of your hardware-this is not the book for
you. If you are trying to figure out what the best index
combination is-again-this is not the book for you. If you want to
know how to add users, or set up replication, or dump a CSV
format text file of data then this is the book for …
I have noticed a definite increase in NoSQL buzz over the last few months. This is partly confirmed by Google Trends, this service shows data relating to how search topics rank:
The last couple of months has seen a dramatic rise in both the number of searches and also the number of news items relating to NoSQL.
But the traditionalists need not yet fret, interest in NoSQL is yet but a blip on the data management radar, as demonstrated by this compairson between NoSQL and MySQL search rankings:
I will be interesting to see how the dynamics of this change
throughout 2010 though.
Related articles by Zemanta …
Done! Here are the slides:
And video:
The MySQL Conference and Expo started with me and Lars Thalmann doing the replication tutorial. Unfortunately, we cannot at this time distribute the slides (please watch the replication tutorial page at the conference site), but there is a replication tutorial package for easy setup of server to play around with—including some sample scripts—and a paper that both explains how the package can be used as well as giving some example setups.
- The software package can be downloaded from the forge and requires Perl at least version 5.6.0 to execute.
- The article can can also be …
The performance work I was involved in in 5.5 had its few moments
of fame today. However, if you looked carefully at the graphs on
Edward's slides, you'd seen that 200% gains come from workloads
where MySQL performance would previously simply deteriorate (128
threads and more). The good news is that we didn't just fix the
high-thread-count results, but significantly increased peak
performance, reached at 32-64 threads. I'm sure community will
figure this out, and post independent benchmarks. The results are
excellent in any case.
Too bad Edward left without taking any questions, the whole thing
looked a bit rushed.