In the first part of this post I discussed the underlying division that drives the debate about open core, and the futility of arguing about what constitutes an “open source company” without any relevant definition.

Since then Monty Widenius has proposed a definition that would exclude any company that does not produce open source software (including open source support providers) and any company that does not provide access to 100% of its code (which would often exclude Red Hat as it moves to open source acquired code).

In the meantime others have declared that there is no such thing as an open source company and …

The MySQL Protocol is a very old thing. Current version is 10, however I have never seen a server which uses anything but version 10. And new features are added without bumping the number. The changes are usually backwards compatible and sometimes you break stuff to be backward compatible.

You know that character set, and most notably Unicode, support was introduced in 4.1 . Other things got added to 4.1 but let's stay with the charsets.

Ulf was pushing me today to file a MySQL bug, which actually doesn't exist anymore, but his programs crash with 5.1.31, where it seems still exists. For a long time we were thinking about the ultimate testing matrix which includes as many as possible MySQL Server instances to check differences in result of the connectors.

I've heard that Paul DuBois have all existing MySQL versions running on a secret box.

Throughout the years MySQL has seen many version suffixes

In posts on June 30 and July 6, I explained how implementing the commands “replace into” and “insert ignore” with TokuDB’s fractal trees data structures can be two orders of magnitude faster than implementing them with B-trees. Towards the end of each post, I hinted at that there are some caveats that complicate the story a little. In this post, I explain one of the complications: secondary indexes.

Secondary indexes act the same way in TokuDB as they do in InnoDB. They store the defined secondary key, and the primary key as a pointer to the rest of the row. So, say the table foo has the following schema:

create …

The closest thing I know of to a “Northern Virginia MySQL Meetup” is the Sterling Database Data Solutions Group. I got in touch with the organizer and we scheduled a meeting next Wednesday July 28th. I’ll be presenting, and so will someone from Fusion-IO, a solid-state storage vendor. This is on short notice, so tell your friends about it! It would be great to grow a strong monthly meetup presence in this area.

Here’s the abstract I sent: “This talk covers best practices to help you get the most out of MySQL performance. It assumes you know a database well, though it need not be MySQL. We’ll cover several angles of the topic. Configuration is usually the first thing people ask about. Although it’s possible to misconfigure MySQL and get …

Guest blogger Pamela Samuelson is the Richard M. Sherman Distinguished Professor of Law and Information at the University of California, Berkeley. She teaches courses on intellectual property, cyberlaw, and information privacy, and she has written and spoken extensively about the challenges that new information technologies pose for traditional legal regimes. A version of this material is scheduled to appear in the November 2010 issue of Communications of the ACM.

Two-thirds of the approximately 700 software entrepreneurs who participated in the 2008 Berkeley Patent Survey report that they neither have nor are seeking patents for innovations embodied in their products and services. These entrepreneurs rate patents as the least important mechanism among seven options for attaining competitive advantage in the marketplace. Even software startups that hold patents regard …

I started translation of Part 3 "Other cases". In this part I mostly describe how wrong settings can lead to misterious errors. First chapter in this part about large amount of data.

Part 3. Other cases.


Chapter 8. Large amount of data.

There are cases when query is just symptom of wrong behavior, but true reason is wrong settings.

One of the cases is too small max_allowed_packet for data sent. MySQL
server variable max_allowed_packet defines maximum possible amount of
data which MySQL server can receive or send. Amount of
max_allowed_packet is specified in bytes.

Error usually looks like:


$mysql51 test <phpconf2009_1.sql

ERROR 1153 (08S01) at line 33: Got a packet …

I am speaking in a few days at OSCON 2010 in Portland, Oregon. My talk, “MySQL Bottleneck Hunters – How Schooner Increased MySQL Performance by 8x” is about how Schooner optimized MySQL to run on modern hardware with flash memory. Come on by if you’re at OSCON!

Here’s the abstract:

MySQL Bottleneck Hunters – How Schooner Increased MySQL Performance by 8x — Thursday, July 22, 2010 at 11:30am

MySQL users have an insatiable need for speed, capacity, and availability, all at a reasonable cost. This session will provide technical overview of the approach that Schooner engineering took to optimize MySQL Enterprise and InnoDB with flash memory, multi-core processors, and DRAM to achieve an 8x …

It is easy for MySQL replication to become bottleneck when Master server is not seriously loaded and the more cores and hard drives the get the larger the difference becomes, as long as replication
remains single thread process. At the same time it is a lot easier to optimize your system when your replication runs normally - if you need to add/remove indexes and do other schema changes you probably would be looking at some methods involving replication if you can't take your system down. So here comes the catch in many systems - we find system is in need for optimization when replication can't catch up but yet optimization process we're going to use relays on replication being functional and being able to catch up quickly.

So the question becomes how can we estimate replication capacity, so we can deal with replication load before slave is unable to catch up.

Need to replication capacity is not only needed in case you're …