Pentaho Solutions

Pentaho Solutions, Business Intelligence and Data Warehousing with Pentaho and MySQL. By Roland Bouman and Jos van Dongen, Wiley 2009. Page count: about 570 pages. (Here’s a link to the publisher’s site.)

The book is big in part because it’s about a GUI tool, so there are the requisite number of screenshots (but not too many). It is structured into four parts, each on a different topic.

The first part is 4 chapters on getting started with Pentaho: from a quick-start through …

I’ve released version 1.1.5 of my improved Cacti templates for MySQL and other components of a LAMP application. This is a pure bug-fix release. One of the bug fixes prevents spikes in graphs, but requires you to rebuild your RRD files. There are upgrade instructions on the project wiki for this and all releases. Use the project issue tracker to view and report issues, and use the project mailing list to discuss the templates and scripts.

The full changelog follows:

2009-12-13: version 1.1.5

  * Support for getting slave lag via mk-heartbeat was broken (issue 87).
  * The …

One of MySQL’s notable projects was splitting the product into two editions: Enterprise Edition and Community Edition. This move alienated many in the community, and failed to create meaningful differentiation on either side, even with a team of people beating the community bushes for “contributions.” The net differentiation was ultimately Jeremy Cole’s SHOW PROFILES functionality, which made Community better than Enterprise. Sun put less effort into making this split work, and eventually they abandoned it.

In an amazing display of chutzpah, Monty Widenius recently asked on his blog for people to write to the EC about the takeover of Sun by Oracle and its effect on MySQL, saying:

I, Michael "Monty" Widenius, the creator of MySQL, is asking you urgently to help save MySQL from Oracle's clutches. Without your immediate help Oracle might get to own MySQL any day now. By writing to the European Commission (EC) you can support this cause and help secure the future development of the product MySQL as an Open Source project.

"Help secure the future development"? Sorry, but that ship has sailed. Specifically, when MySQL was sold to Sun. There were many other missed opportunities over the years to keep MySQL as a good open source project. Some of the missteps:

• Bringing in venture capitalists
• Selling to Sun instead of making …

InnoDB flushes pages in very simple logic – it goes to the tail of LRUsed list (which has pages for whole buffer pool), and walks it from tail to head, until it finds enough pages to flush. If flushing is aggressive, dirty pages will be only at the head of the list, not at the tail, but InnoDB will still be traversing it fully, tail to head.

Look at that, Jay Janssen notices:

I rarely say the buffer pool beyond a few percent dirty.

Devananda writes:

by enabling adaptive flushing, InnoDB purged modified data much more aggressively, resulting in very little unflushed changes

See, while it traverses the whole buffer pool it holds global buffer pool lock. When some thread that holds kernel mutex tries to acquire …

As the deadline for EC to decide if Oracle can acquire Sun and hence MySQL is coming up the tensions seems to heat up. Monty posts his open letter calling for help lobbying EC to stop Oracle from buying MySQL .

Entry posted by peter | One comment

Add to: | | …

I no longer work at MySQL/Sun Microsystems. So if you’ve sent any email to {colin|byte}@mysql.com, or {colin.charles|byte}@sun.com in the last month, they’d silently have gone into /dev/null as I have not had access to my accounts. Don’t hesitate to resend them to byte@bytebot.net if you’d like me to see them.

I’ve enjoyed my journey at MySQL, but it just seems like its time to move on. I haven’t left the MySQL community yet, though. In fact, I expect nothing but more active participation in it.

What’s next? I’m going to split my time between working on MariaDB, at Monty Program Ab, as well as Open Ocean Capital. I’ll work with Open Ocean portfolio companies Web of Trust and MoSync.

Do you use …

First of all, I want to link to a blog article written by the founder of MySQL to help MySQL being rescued - everybody can stand up and tell the European Commision why the Oracle/Sun deal threatens MySQL. Second, due to a personal request, I want to make clear that this posting reflects my personal opinion of the case.

Third, I have been thinking about the markets both database systems address and why MySQL really competes to Oracle in one way or another. There are several voices who claimed that MySQL is not a competitor to Oracle, but if you know "Project Peter", Sun (the current owner of the trademark MySQL and its source code) targets Oracle customers in order to convince them migrating to MySQL.

…

Dear MySQL,

I feel ashamed that I ever wanted you to support 4.0->5.1 replication, and apologize for that. I really understand that it was really egoistic of me even to consider you should be involved in this.

I even understand that 5.0 is running out of active support (I’m not questioning that you’ll stop supporting 4.1 entirely too), and you’ll stop doing pretty much anything to 5.0, except “critical security fixes” (w00t, I managed to get one into 4.1, 8 year old MITM flaw :).

I really understand that supporting more than one release is …

I need to hack MySQL to stop parsing LIMIT a, b. This is a high-risk feature for an OLTP RDBMS. I saw the following on a server that was already too busy.

select ... from foo where ... LIMIT 2000000, 10;
select ... from foo where ... LIMIT 2000010, 10;
select ... from foo where ... LIMIT 2000020, 10;

I hope this didn't start at LIMIT 0, 30 as that is a slow way to fetch rows. Each of the queries above scans ~2M rows from an index before returning the last 30 rows. Queries like this have a lousy response time and make mysqld do too much work.

There is a way to make this query efficient but first I will explain why LIMIT a, b is O(N*N). It has been a long time since I took an algorithms course, so I apologize in advance for incorrect terminology. This assumes an index exists for the columns in the ORDER BY clause. When a sequence …