The problem: You’re creating an (InnoDB) table with foreign key constraints:

CREATE TABLE a (
  b INT NOT NULL,
FOREIGN KEY b REFERENCES c(d)
) ENGINE=InnoDB;

and MySQL throws an ERROR 1005 (HY000): Can't create table ... (errno: 150)

In 95% of the cases, this means you need to create an index on c(d):

ALTER TABLE c ADD PRIMARY KEY (d)

Just a subjective observation, been through a few bookstores this arvo (sorry, afternoon - Australian ;-) and I tend to do a quick check of the computer section to see what MySQL books are there.
It appears that over the last year or perhaps even longer, fewer new MySQL books have come out, and fewer MySQL books hang around on the shelves. Less interest, I don't know.
O'Reilly's annual report on the book market probably has some insight into this but it's late in the evening here so I'm not going to delve into that right now.
Anyway, it's quite possible that the market is fairly saturated, and there are some good books out there covering most features and uses. So all that remains is new functionality, and there hasn't really been that much which warrants writing a completely new book about it. Stored procedures was probably the last such instance. Like, partitioning is interesting, but not for a full book. Falcon, diddums (at …

I started working on my upcoming talk at PGCon 2008 and realized that I haven't put my talk from PostgreSQL Conference East 2008  - PostgreSQL and Benchmarks online yet.

 More on the upcoming presentation later.

I'm hosting a MySQL Tour event in Helsinki, probably this is the last stop on the tour so it will end in the same city where MySQL got started. If you are nearby, please pop in!

***

MySQL Tour visits Open Tuesday in Helsinki May 6th

This winter we haven't had as many Open Tuesday meetings as we had last year,
but we will finish off the season with meeting Sun and MySQL on May 6th at
18:00, in the usual place Club Ahjo, Bulevardi 4, Helsinki.

read more

There are interesting posts these day about future of MySQL Replication by Brian Frank and Arjen.

I think it very interesting to take a look at a bit bigger picture using framework from Innovators Dilemma and Innovators Solution.

I’m not going to speak about disruption and commoditisation of Database …

Coming from Berlin and Hamburg meetups, I am about to board a plane for San Francisco and the MySQL Users Conference. I am looking forward to see a lot of familiar faces from the community and many still unfamiliar ones that I have been contacting in the latest weeks. New colleagues (plenty of them!) new community people, new business partners.
And the conference will also bring some surprises. The ones coming from MySQL will be old news for me (oh, the joy of being an insider!), but a few ones are still exciting because they will be in the making until the very last minute. Much meat will be on the grill. Stay tuned.
The program itself is interesting and charming. I will attend the sessions on my private schedule as a personal treat, enjoying the technology as a kid in a toy store.
And of course I will enjoy my tutorial on MySQL Proxy and the session on MySQL Sandbox. I will treat …

Updated On good advice from Sheeri I made a few comments clearer.

We have proposed that the integral “MySQL Community Photo Day” be on Thursday April 17 2008, the final day of the MySQL Users Conference.

Wear a t-shirt from an open source community project on Thursday, whether a PrimeBase PBXT one or your favorite open source project (of course I prefer the first option). Get your photo taken with the masses of community supporters. If your not attending this year, this doesn’t mean you can’t also contribute a photo yourself from what location you are from. Save a saving fund for next year but get us a photo.

It doesn’t have to just be Thursday, we will accept photos at any time before then. Upload a photo and win a prize. (Baron you definitely get chocolate)
We have created a Flickr group called “MySQL Community Photo Day” at …

This year’s conference has a great lineup. As usual, with 8 sessions concurrently, it’s impossible to pick which ones I want to see. However, I did learn a few things from last year’s conference, which I think will help me get more out of it this time.

Number one rule: not all sessions are created equal. I can’t say for sure, but I’m pretty sure that when you see “How Product X Will Scale Your Databases” presented by a person from Company X, you can reasonably suspect that Company X is paying for this privilege, and it’s not really a session as much as a product demo. These sessions were not reviewed and voted on by the community (I know, because I was one of the community members who were asked to review and vote on proposals. Maybe I’m being a whistle-blower and won’t get this honor next year as a result…)

Number two rule: if the description is vague, or if it sounds like regurgitation, I’m skeptical. For …

By the way, the entry counter at Planet MySQL stands at 9982. Which blogger will capture the illustrious 10,000th entry, and will MySQL hand out a prize? I think it's worthy, Planet MySQL has proven to be a great resource over the years.

Of course, there have been more posts, but prior to me setting up the current software infrastructure (March 2004), there was no archiving of old posts. Actually, it'd be great to be able to search the archives. Fairly simple to implement, MySQL Community team just needs to put the code out there so anyone external can do it. I'm happy to be embarassed (it's my code ;-) so no worries there.

But let's see, so it's been about 4 years, that's 2500 entries per year, about 48 entries per week. Not bad! I asked Lenz some time ago if he could run a query to show the trend of # of queries per week/month over time, also split out between …

There has been some discussion recently regarding the death of MySQL Read Replication starting with Brian Aker and then Farhan, Arjen and Paul have all chimed in. Whatever you want to call it, the next generation of replication approach is clearly on the agenda of the industry leaders and pack followers. We should take a programmatic look however and ask ourselves a few questions. Such as:

1. The Use — What is/was MySQL Replication used for?
2. The Reasons — Why was it used?
3. The Problems — Why is there a need for something better, different or …