Apparently High Performance MySQL, 2nd Edition is selling quite well — I’m not sure exactly how well — because we’re preparing for a second printing. This makes me very happy. I don’t think they anticipated going back to the press for quite some time.

The book fluctuates between sales rank 1000 and 2000 on Amazon during the day, and has reached as high as 600 or so. This is just phenomenal. The O’Reilly team was psyched when it broke 5000, and so was I — but now we’ve stayed under 2000 for a long time (except when Amazon sold out of it). Frankly I’d have thought that for a niche-market book like this, we’d have been in the 10,000 range or something like that.

Clearly we (the authors, editors, publisher, etc) have done something right! This is a great feeling.

Thanks for sending errata, by the way. I have just completed proofreading the whole …

The Sphinx project just released version 0.9.8, with many enhancements since the previous release. There’s never been a better time to try it out. It’s really cool technology.

What is Sphinx? Glad you asked. It’s fast, efficient, scalable, relevant full-text searching and a heck of a lot more. In fact, Sphinx complements MySQL for a lot of non-search queries that MySQL frankly isn’t very good at, including WHERE clauses on low-selectivity columns, ORDER BY with a LIMIT and OFFSET, and GROUP BY. A lot of you are probably running fairly simple queries with these constructs and getting really bad performance in MySQL. I see it a lot when I’m working with clients, and there’s often not much room for optimization. Sphinx can execute a subset of such queries very efficiently, due to its smart I/O algorithms and the way it uses memory. By “subset” I mean you don’t get the …

Dear reader, this is a challenge. How’s your MySQL prowess? You know about LIMIT: it cuts off the results at the specified number.

mysql&gts; select actor_id from sakila.actor where actor_id % 5 = 0 limit 5;
+----------+
| actor_id |
+----------+
|        5 | 
|       10 | 
|       15 | 
|       20 | 
|       25 | 
+----------+
5 rows in set (0.00 sec)

But that query actually accessed 25 rows. What if I want to say “return up to 5 rows, but don’t read any more than 20 rows to find them?”

Right now I’ve got the following:

mysql> select actor_id, @rows
    -> from actor, (select @rows := 0) as x where
    ->    ((@rows := @rows + 1) <= 20)
    ->    and actor_id % 5 = 0 
    -> limit 5;
+----------+-------+
| actor_id | @rows |
+----------+-------+
|        5 | 5     | 
|       10 | 10    | 
|       15 | 15    | 
|       20 | 20    | 
+----------+-------+
4 rows in set (0.00 sec)

The …

The book is done now, right? What’s next?

Don’t tell my wife this, but a book is never done.

Right now I’m proofreading the printed copy. I proofread PDF after PDF during production, but some problems will always slip through and make it to paper. I’m finding quite a few little mistakes. For example, at one point we refer to TPC as TCP three times in a row. Oops.

These problems will be corrected in the next printing. Please notify me if you find any errors yourself, and I’ll add them to the list of things to fix! Also let me know if you find things that should just be “fixed” in general. For example, the layout and page-breaking on pages 364 and 365 is totally confusing — it’s hard to tell which figures are associated with which text.

I’m not offering rewards like Donald Knuth, sorry…

I will place a list of errata on the official …

Percona is looking to hire someone to develop Maatkit, among other things.

If I weren’t having so much fun being the consulting team lead, I’d be doing it myself. (In fact, I’m still hacking on it a lot. Got some pretty fun stuff done this weekend.) I don’t know what the rest of the world thinks, but I think Maatkit is a damn enjoyable project to work on. Hopefully someone else will have the same kind of mindset and want to get paid for it, unlike poor working-on-the-weekends me.

I’m not stepping away from the project. It’s just grown a lot, and there is room and money to grow it much more. This is actually the best compliment to the project: that it is worth hiring someone to keep improving it. Lots of people are using it, and there’s a lot …

My post on what it’s like to write a technical book was a stream-of-consciousness look at the process of writing High Performance MySQL, Second Edition. I got a lot of responses from it and learned some neat things I wouldn’t have learned if I hadn’t written the post. I also got a lot of questions, and my editor wrote a response too. I want to follow up on these things.

Was I fair, balanced and honest?

I really intended to write the post as just “here’s what it’s like, just so you’re prepared.” But at some point I got really deep into it and lost my context. That’s when I started to write about the things that didn’t go so smoothly with the publisher, …

The book, that is. My dog is already studying it. You should buy a few copies for yourself, your family, and all your pets.

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The other day I was explaining options to someone who wanted to know about archiving data in MySQL. “So,” he said, “I might have to code my app to look for the data in two places?” The disadvantage of this is that his app might be more complex. Another disadvantage is that it might take two queries — if you look for a user in the usual location and it’s not there, you have to look for it elsewhere.

One way to deal with this, as long as the archived data is on the same server, is a UNION.

select user_id from user where user_id = 123
union all
select user_id from user_archive where user_id = 123;

The benefit is that you don’t have to issue two queries. That saves network round trips, and makes your code shorter. But it has a disadvantage, too: you’re still querying the archive table when you don’t …

As you probably know, I recently finished writing a book with a few co-authors. I kept notes along the way and wanted to describe the process for those who are thinking about writing a book, too.

Update: see the followup post for more of the story, including my editor’s responses.

I think it’s important to be objective; my purpose here is to help prospective authors get a feeling of what it’s like, and it’s not all good (but I’d encourage people to do it anyway). Hopefully I won’t come off as sounding peeved at anyone or like I’m trying to put people down. I’ll have a lot to say about what went right and wrong, and how it helped and hindered the process.

Please excuse the rambling nature of this post. I’d love to …

Final versions of High Performance MySQL, Second Edition sample content are posted at the official website. You can download unrestricted PDFs of the foreword, table of contents, chapter 4 (Query Performance Optimization), and the index.

PDF, Sample Chapter