This afternoon, Arjen Lentz and I were discussing InnoDB’s behavior without a declared PRIMARY KEY, and the topic felt interesting enough and undocumented enough to warrant its own short post.

Background on InnoDB clustered keys

In The physical structure of InnoDB index pages I described how “Everything is an index in InnoDB”. This means that InnoDB must always have a “cluster key” for each table, which is normally the PRIMARY KEY. The manual has this to say in Clustered and Secondary Indexes:

If the table has no PRIMARY KEY or suitable UNIQUE index, InnoDB internally generates a hidden clustered

  [Read more...]

Normal 0 false false false EN-US X-NONE X-NONE Everybody loves free. It is the best marketing term one could use. Once you say “FREE” the people come running. Free makes you very popular. Whether you are a politician offering something for free, or a company providing free stuff, you gain instant popularity.

Xeround is shutting down their MySQL Database as a Service (DBaaS) because their free  [Read more...]

Sharing my experience of compiling TokuDB + MariaDB 5.5. Why? Because I must have this patch to Sphinx 2.0.4.

Note: I was using what seems to be the "old" method of compiling; quoting Leif Walsh:

... We are looking at deprecating that method of building (MariaDB source plus binary fractal tree handlerton).  It only really needed to be that complex when we were closed source.

I also tried the "new" method of compiling, which I couldn't work out.

Here's how it goes: TokuDB is newly released as open source. As such, it got a lot of attention, many downloads and I hope it will succeed.

However as stable as the

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I’ve put online the slides for the two talks that I сo-presented at the Percona Live conference:

• Advanced query optimizer tuning and analysis tutorial (slideshare, pdf)
• MariaDB Cassandra interoperability session (slideshare, pdf)

The tutorial tries to cover most areas of the optimizer, with focus

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Got a packet bigger than ‘slave_max_allowed_packet’ bytes and binlog_format=STATEMENT|MIXED

Since version 5.1.64 MySQL introduces a new variable named slave_max_allowed_packet, which was introduced to allow large updates using row-based replication do not cause replication to fail when exceeded max_allowed_packet.

The problem is if you have you replication using binlog_format=STATEMENT or binlog_format=MIXED it ignores this option and use as limit for queries what is on max_allowed_packet variable but still reporting on slave_max_allowed_packet causing

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5 years of MySQL

People often write a blog post when they reach some nice anniversary since they joined MySQL community. Well, for those old enough it usually means when they joined MySQL AB as employee. For me this was January 2008. Because I didn't remember the month correctly, I haven't blogged anything then, but decided to save it for a better opportunity - now.

TL;DR Starting this week I will be working for 10gen, selling MongoDB to the Nordics. This blog post is really long - even then it doesn't contain the most interesting stories, I'm not sure if they can ever be published. Sorry for the length, but remember you don't need to read all at once. This is my last MySQL post so save some of it for cold winter days!

2008 - Sun acquisition

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Hey everybody!

The Percona Live MySQL Conference and Expo just wrapped up last week and we’re looking to get some conference in review talk from everyone! Talk about your favorite sessions, new things you learned, and your overall opinion of the conference!

Hop online Wednesday at 12:00pm PDT (19:00 GMT) to join the discussion and share your experience from the 2013 Percona Live: MySQL Conference and Expo.

Be sure to watch this twitter search or this blog post get a link for the google hangout tomorrow!

Some talks that were specifically called out:

• Monitoring MySQL with OpenTSDB by Geoffrey Anderson

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I wasn’t at the MySQL Conference this year but it was very nice to follow this event from Paris.
Of course I didn’t feel the general atmosphere by visiting booths or met fabulous people.
But it was a great opportunity to offer you a live post about the conference with an external point of view.

Twitter, RSS feeds (yes Google, I still use RSS), Planet MySQL and infiltrators were my best friends during this crazy week.

I would like to summarize the major announcements and events occurs during this tenth edition.
 

Oracle at Percona Live!

 
Yes, Oracle was at Percona Live 2013 and it was for the best.
I invite you to watch this

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As you may know, I'm a big fan of JSON and I am working on releasing a new version of my JSON tools real soon. Meanwhile on the SkySQL Solutions Day on April 26 I gave a talk on JSON with MySQL and MariaDB, and the slides are available on slideshare.

/Karlsson

Read the original article at Make MySQL clustering work for you

We’ve told you all about MySQL mult-master replication’s limitations. If you write to two masters it is bound to fail for myriad reasons. Now what? Do what the pros do that’s what. A. Don’t write to both masters Using multi-master replication works great as long as you do so in active-passive mode. Never write to [...]

For more articles like these go to Sean Hull's Scalable Startups

Related posts:

Limitations of MySQL row-based replication

No tools to reconcile MySQL with two

  [Read more...]

Software Carpentry is running a 2-day software skills boot camp in Boston, June 24-25th 2013, for women in science, engineering, medicine, and related research
areas. Registration is $20.

Boot camps alternate short tutorials with hands-on practical exercises. You are taught tools and concepts you can use immediately to increase your productivity and improve confidence in your results. Topics covered include the Unix shell, version control, basic Python programming, testing, and debugging — the core skills needed to write, test and manage research software.

This boot camp is open to women at all stages of their research careers, from graduate students, post-docs, and faculty to staff scientists

  [Read more...]

Today I downloaded Fedora 19 alpha to give it a spin. Some quick notes.

You can get MySQL by asking for the package community-mysql-server. This is 5.5.31. If you ask for stock “mysql” (i.e. yum install mysql-server), you automatically get MariaDB 5.5.30 (mariadb-server).

Fedora 19 runs systemd, so there is no longer /etc/init.d/mysql to start/stop/restart. So just do systemctl enable mysqld.service. Then perform: systemctl start mysqld.service. Replace start with: stop/status too. You can disable it too if you want.

MariaDB 10.0.2 compiles cleanly on Fedora 19 with gcc-4.8. Just perform: yum install bzr gzip tar gcc gcc-c++ make libtool bison ncurses-devel zlib-devel automake autoconf cmake. Get the source code (I just downloaded it). Do BUILD/compile-pentium64-max. Wait. Run make

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Oracle Database has a feature which allows it to query millions of rows in parallel while executing a join which has a big fanout.
How important is it that a database server has a lot of intra-query concurrency? Does it still make a lot of sense to run an analytical query in parallel threads, on a single machine?

While at Percona Live, there was a lot of talk about the future of MySQL, and some even mentioned this as being part of the future.

The reason for intra-query parallelism has always been to fill up the pipeline to disk with lots of parallel queries. Indeed, this pipe is thick and long - and if used, it'd better produce a lot of data at once. Efficiency of CPU utilization is sacrificed to achieve efficiency of a rotating disk drive.

Yet in DaaS world this all fails to make sense to me. In a cloud, one execution unit is not one CPU, but one instance, and one  [Read more...]