Rob Wultsch's MySQL Talk at PostgreSQL West

I thought this talk deserved a blog post of its own, so here it is.  I have to admit that I approach this topic with some trepidation.  The MySQL vs. PostgreSQL debate is one of those things that people get touchy about.  Still, I'm pleased that not only Rob, but a number of other MySQL community members who I did not get a chance to meet, came to the conference, and it sounds like it will be our community's turn to visit their conference in April of next year.  Rob was kind enough to offer to introduce me to some of the MySQL community members who were there, and I, well, I didn't take him up on it.  That's something I'd like to rectify down the road, but unfortunately this was a very compressed trip for me, and the number of people I had time to talk to and meet with was much less than what I would have liked.

PostgreSQL West Talks

As I blogged about before the conference, I gave two talks this year at PostgreSQL West.  The first was a talk on the query optimizer, which I've given before, and the second talk was on using the system catalogs, which was new.  While the second one was well-attended, the first one was packed.  I keep hoping I'll think of something to talk about that people find even more interesting than the query planner, but so far no luck.  Slides for both presentations are now posted; I've added two slides to the system catalogs presentation that weren't there when I gave the talk, but probably should have been.

Nearly all the talks I attended were good.  Some of the best were Greg Smith's talk on Righting Your Writes (slides), Gabrielle Roth's talk on PostgreSQL monitoring tools, and Joe Conway's talk on Building an Open Geospatial Technology Stack (which was actually given in part by Jeff Hamann, who has a company, and a book).  All three of these, and a number of the others, were rich with the sort of anecdotal information that it's hard to get out of the documentation: How exactly do you set this up? How well does it actually work?  What are its best and worst points?

Another memorable talk was Rob Wultsch's talk entitled "MySQL: The Elephant in the Room".  But that talk really deserves a blog post all of its own.  Stay tuned.

Here Comes PostgreSQL West

In just a few days, I'll be off to PostgreSQL West.  I've attended PostgreSQL East and PGCon both of the last two years, but this will be my first trip out to PG West.  As with past conferences, this will be a good opportunity for me to catch up with people I normally speak with only via the Internet.  But, there's something that's a little different about this one.  Take a look at the agenda.

WAL Reliability

I recently learned, somewhat to my chagrin, that operating systems are pathological liars, and in particular that they habitually lie about whether data has actually been written to disk.  If you use any database product, you should care about this, because it can result in unfixable, and in some cases undetected, corruption of your database.  First, a question.  On which of the following operating systems do fsync() and related calls behave properly out of the box?

A. Linux
B. Windows
C. MacOS

Choosing a Datastore

In thinking about which database might be best for any particular job, it's easy to get lost in the PR. Advocates of traditional relational database systems like Oracle and PostgreSQL tend to focus on the fact that systems are feature-rich and provide features such as atomicity, consistency, isolation, and durability (ACID), while advocates of document databases (like MongoDB) and key-value stores (memcached, Dynamo, Riak, and many others) tend to focus on performance, horizontal scalability, and ease of configuration.  This is obviously an apples-and-oranges comparison, and a good deal of misunderstanding and finger-pointing can result.  Of course, the real situation is a bit more complicated: everyone really wants to have all of these features, and any trade-off between them is bound to be difficult.

Down To Six

From early July until the beginning of this week, the PostgreSQL project has been maintaining eight active branches: 7.4, 8.0, 8.1, 8.2, 8.3, 8.4, 9.0, and the master branch (9.1devel).   As a result, a significant number of bug fixes and security updates had to be back-patched into all of those releases.  At least for me, the recent switch to git has made back-patching, at least for simple cases, a whole lot simpler.  But it's still a fair amount of work - some parts of the code have changed a good deal since 2003, when 7.4 was released.

SURGE Recap

Bruce Momjian and I spent Thursday and Friday of last week in Baltimore, attending Surge.  It was a great conference.  I think the best speakers were Bryan Cantrill of Joyent (@bcantrill), John Allspaw of Etsy (@allspaw), and Artur Bergman of Wikia (@crucially), but there were many other good talks as well.  The theme of the conference was scalability, and a number of speakers discussed how they'd tackled scalability challenges.  Most seem to have started out with an infrastructure based on MySQL or PostgreSQL and added other technologies around the core database to improve scalability, especially Lucene and memcached.  But there were some interesting exceptions, such as a talk by Mike Malone wherein he described building a system to manage spatial data (along the lines of PostGIS) on top of Apache Cassandra.

Some general themes I took away from the conference: