So last week MySQL was on site at work for MySQL DBA
Certification prep. class (which was very awesome and highly
recommended, by the way) and one of the things that came up was
how much faster enumerated types would be over using JOINs, say
to store things like the categories of a blog not unlike this
one. Well, the issue had been bugging me so I thought I would
figure it out. This time around, I wanted to get my feet wet with
mysqlslap, since it basically does the same
thing as my SQLBuster, only better :)
What I did was basically run two tests. One was running my
original query to pull up a single blog post, which contained two
JOINs to de-normalize the categories and moods. The categories
and moods tables are very small - less than 20 records, but I do
have indexes setup …
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This is a friendly reminder that we have opened our Call for Participation for the MySQL Users Conference 15-18 April 2008 in Santa Clara, California.
Yes, 15 April next year may seem far away. But 30 October this year isn’t. And that’s when the Call for Paper closes.
Some UC 2008 highlights:
- Conference theme is “Harnessing the Power of MySQL”
- We expect to bring over 1,500 open source and database users together
- Over 100 sessions, geared toward many skill levels (novice to expert)
Consider to present, especially if you belong to one or more of the below …
[Read more]Thought I’d mention that a new case study featuring Pentaho and Kettle showed up over at the Database Trends and Applications. The name of the paper is called “Loma Linda University Health Care Deploys Pentaho BI” (PDF).
To quote :
With commercial products you don’t know if you are getting what you want, but with open source you can create proofs-of-concept. And the TCO is so much lower.
Until next time!
Matt
Recent couple of days our team was pointed to number of bugs in MySQL 5.0 which again seriously shakes the confidence in both MySQL Quality Control and bug fix promptness.
Let me just take couple of bugs as examples:
Triggers broken with auto-increment columns for Innodb tables (bug 26316). As you can see this bug is reported in February - over 6 months ago and it is still in verified state even though it has "serious" severity.
ORDER By DESC broken for Innodb tables (bug 31001) This is also very interesting - the VERY basic functionality gets broken and passes quality control. And why it is broken ? Because minor optimization was implemented in MySQL 5.0.
Surely …
[Read more]
We use a lot of dual master setups for redundancy and
recoverability. Typically, most apps can't write to both masters
at the same time, so for consistency we keep only one of the
masters read-write at any given instant. To switch over
gracefully, turn the primary read-only, wait for replication to
catch up, turn the secondary read-write. Simple, eh?
Well, I've just had a report that setting the primary read-only
caused a transaction to be partially replicated to a slave. Wait,
what? If I'm reading the email correctly, they switched masters
in the middle of a transaction. The transaction commit correctly
failed on the master with a read-only error, but somehow the
other master (or a slave) got part of the transaction that failed
and had to be skipped.
This was an innodb table in MySQL 5.0. My first thought was that
XA was disabled (though we typically use 4.1 here, so I thought
of innodb_safe_binlog). I verified that the …
I am very good at just staying up late to adjust to a timezone. I can do this fairly reliably. Going to the US and Europe can be done by this method (rather well). Coming back is another story though. Going to sleep at an earlier time (for me) doesn’t come easy. Grr…
Current MySQL Webinars:
http://mysql.com/news-and-events/web-seminars/
Archived MySQL Webinars:
http://mysql.com/news-and-events/on-demand-webinars/
MySQL University:
http://forge.mysql.com/wiki/MySQL_University
Classes for October 2007:
Architecture of NBD
Following a Query Back and Forth in the Server
How to Create a Test Case
Previous University Classes:
http://forge.mysql.com/wiki/MySQL_University#Previous_Sessions
Skoll -- Community-Based Testing Framework
Demo video:
…
This has been covered before, but I was just setting up a new force type on our servers and thought I would mention it for the fun of it. You see lots of stuff about using mod_rewrite to make friendly URLs or SEO friendly URLs. But, if you are using PHP (and I guess other Apache modules) you can do it without mod_rewrite. We have been doing this for a while at dealnews. Even before SEO was an issue.
Setting up Apache
From the docs, the ForceType directive “forces all matching files to be served as the content type given by media type.” Here is an example configuration:
<Location /deals>
ForceType application/x-httpd-php
</Location>
Now any URL like …
[Read more]
after the heidelberg mysql developers meeting, we got on to the
serious business of oktoberfest in munich. one of my coworkers
had secured tables inside the hippodrom for two of the days, and
we took full advantage of that.
the weather was not very good while we were in munich, and we
were definitely starting to feel the end of the trip, so we did
not explore munich outside of the oktoberfest grounds. that just
means we will have to go back another time.
this time my pictures actually have some people in them.
and lots of beer.
I wanted to point out something that might not be obvious from
the name: MySQL Parallel Dump can be used as a generic wrapper to
discover tables and databases, and fork off worker processes to
do something to them in parallel. That "something" can easily be
invoking mysqlcheck -- or any other program. This
makes it really easy for you to do multi-threaded
whatever-you-need-to-do on MySQL tables. Here's how.