There are two ways InnoDB can organize tablespaces. First is when all data, indexes and system buffers are stored in a single tablespace. This is typicaly one or several ibdata files. A well known innodb_file_per_table option brings the second one. Tables and system areas are split into different files. Usually system tablespace is located in ibdata1 file and every InnoDB table has two files e.g.  actor.frm and actor.ibd.

The annoying thing about .ibd files you can’t easily copy the an .ibd file to another MySQL server. If you try to very often you’ll get an error in the log:

InnoDB: Error: tablespace id is 10 in the data dictionary
InnoDB: but in file ./sakila/actor.ibd it is 15!

However sometimes you have to connect the .ibd file to an alien ibdata1.

There are several situation when you have to:

1. ibdata1 is erroneously removed

2. ibdata1 is …

https://code.launchpad.net/~stewart/drizzle/json-interface/+merge/59859

Currently a very early version of course, but it’s there in trunk if you want to play with it. Just have libcurl and libevent installed and you can submit queries via HTTP and JSON. Of course, the next steps are getting a true non-sql interface going and seeing how people go with it.

Oracle is running MySQL seminars during the next few weeks in Europe! Those free events represent a great opportunity to learn, to meet Oracle’s MySQL team members face to face & have all your questions answered, and to network with other MySQL users & customers.

Here are the details and how to register:

- Rome, May 19th - Register here

- Zürich, May 25th - Register here

- Langen (near Frankfurt), May 26th – Seminar dedicated to channel partners - …

I’ve used Vertica, a commercial column-based database storage engine, and was reasonably impressed. During O’Reilly MySQL conference last month, I checked out Infobright’s vendor booth and talked with some users. I became curious and wanted to test it out. Infobright has a free community version (ICE Infobright Community Edition)of its column-based storage engine that works with MySQL, which was what I used for my testing. I have no relationship with Infobright whatsoever, I happen to think that column-based storage can be a potentially disruptive technology in the BI/DW field. I’d love to hear your comments/experiences.

Here are some noteworthy points:

1. Setup is pretty easy. You can follow steps here. Note that the package has most relavant MySQL tools. A separate install of mysql client and server is NOT needed.

The ICE …

I just sent an e-mail to the MariaDB announce list (a low-traffic list to which you should subscribe if you’re only interested in important news) the release announcement for MariaDB 5.2.6. The announcement has much more information, as do the release notes and changelog.

Much of the project’s focus over the past weeks has been on the 5.3 and 5.5 series, as beta releases are something we’d like to do very soon. Add to this the continued discussions of potential 5.6 work initially started in Lisbon and the MySQL Users’ Conference last month, and it’s a …

Next Monday, May 16, I will be hosting session at the Open Source Business Conference in San Francisco focused on NoSQL, NewSQL and Beyond.

The presentation covers our recently published report of the same name, and provides some additional context on the role of open source in driving innovation in distributed data management.

Specifically, the presentation looks at the evolving influence of open source in the database market and the context for the emergence of new database alternatives.

I’ll be walking through the six core drivers that have driven the development …

The Mysqlnd replication and load balancing plugin alpha release has focused on laying foundations for read-write splitting and load balancing. Thus, we can now look into more juicy topics such as support of schemata based partitioning to increase the granularity of load balancing. Not every slave server needs to replicate all schemata (databases) and tables of the master. The plugin load balancer shall be aware of it and transparently pick the server which has the entities required to execute a statement. Some brainstorming…

The Mysqlnd replication and load balancing plugin alpha release has focused on laying foundations for read-write splitting and load balancing. Thus, we can now look into more juicy topics such as support of schemata based partitioning to increase the granularity of load balancing. Not every slave server needs to replicate all schemata (databases) and tables of the master. The plugin load balancer shall be aware of it and transparently pick the server which has the entities required to execute a statement. Some brainstorming…

Lesson for the week: If you really want to stir up an anthill, attack the conventional wisdom of code development best practices.

In other news ...

Another piece of Sun falls off the good ship Oracle

At this point, I could almost follow the practice of Gregg Easterbrook 's Tuesday Morning Quarterback and put this text on Autotext, but in the past week, Oracle cast off another piece of their acquired Sun technology. In this case, it was the integrated build platform "Hudson." Either fed up with the infighting that had led to the spin-off "Jenkins" project, or simply …

I’ve recently been blogging about how partitioning is a poor man’s answer to covering indexes. I got the following comment from Jaimie Sirovich:

“There are many environments where you could end up creating N! indices to cover queries for queries against lots of dimensions.”

[Just a note: this is only one of several points he made. I just wanted to dig into this one in some detail. Here goes...]

Although it is, in theory, possible to generate a workload that would take N! indexes, this is not a realistic (or useful) bound (leaving aside that this workload would kill partitioning!). For one thing, it would take N! queries to exercise all those indexes. And the queries would have to include every field in the where clause — as we’ll get into below.

So what is a reasonable bound on the number of covering indexes that …