I came home very tired yesterday, just walking around as a big MySQL billboard and I left with mixed feelings really.

First feelings were Happiness + Anger (=Love??). I had a nice dinner with Bruce and Magnus (PostgreSQL) on Thursday, met others at their booth and attended a few talks both Saturday and Sunday. I'm interested in their stuff, I do like PostgreSQL, just like probably everyone else in MySQL. But, I got very angry about 2 remarks made in the DevRoom: "MySQL loses data" and the infamous and idiotic "MySQL has no transactions". FFS! The latter was corrected on the spot, that REALLY pissed me off (remark made by non-PostgreSQL crew btw).
Anyway, overall, I did like what I was hearing, the project is going well, and lots of cool stuff coming in! Very nice! Funny thing though: "Who's using Partitioning?", one guy (as far as I could see) put up his finger.

Next feeling: Amazed! Drupal! I don't like PHP, bah, …

Luc just pointed me with to his recording of my talk about Drupal and MySQL HA yesterday at the Drupal Room at Fosdem

He also uploaded some other video's from the Drupal room.

More about my Fosdem 2008 experience later :)

I’ve been working with the folks working on OpenSolaris for a few months now providing advice and input on getting MySQL and the connectors (C/ODBC and C/J) installed as a standard component. Having got the basics in, the team are now looking at adding both 32-bit and 64-bit packages.

The question raised at the end of last week was whether OpenSolaris should enable 64-bit builds by default in 64-bit installations, and whether there was a noticeable performance difference that would make this worthwhile.

I did some initial tests on Friday which showed that there was a small increase (10-15%) of the packaged 64-bit installations over 32-bit under x86 using snv_81. Tests were executed using the included sql-bench tool, and this was a single execution run of each package for 5.0.56. Transactions are missing because I hadn’t enabled transactions in the tests.

For a change, let me remind you of the upcoming MySQL Users Conference in Santa Clara. It’s less than two months from now; it’ll be from Monday 14 April 2008 to Thursday 17 April 2008. Same place as last year: Santa Clara, California, USA.

My reminder is triggered by the fact that tomorrow is the last day for Early Registration, by which conference participation costs 1299 instead of 1499 dollars (or, if you skip the Monday tutorials, 999 instead of 1199 dollars). In short, early registration saves you 200 dollars.

I do think the UC is at least as interesting as last year, and I’m very happy about our …

Today’s entry is from an anonymous contributor. Keep ‘em coming!

Suppose you issue the following list of commands:

CREATE TABLE fk_relations (
  key1 INT NOT NULL PRIMARY KEY,
  key2 INT NOT NULL UNIQUE
);
INSERT INTO fk_relations VALUES (1,1), (2,2);

The table now contains (1,1) and (2,2). We then do

REPLACE INTO fk_relations VALUES (1,3);

Question 1: The table now contains (1,3) and (2,2). Explain why.
We now do:

REPLACE INTO fk_relations VALUES (1,2);

Question 2: The table now contains the single row (1,2). Why?

Question 3: What is the value of Rows affected in your client after each of the two REPLACE statements?

(more…)

As I wrote earlier, we (me and Ranger) have done an assessment of the impact of new 6.0 subquery optimizations. First, we've done a search for performance issues in MySQL's bug database. The raw list is here, and the here is a summary chart:

Search for customer issues in MySQL's issue tracker system has produced a similar picture (raw list):

Search in DBT-{1,2,3,4} open source benchmark suites produced a radically different result though (raw data is …

Hi all,

Thank you for reading!

The aim of this blog is sharing some information on the MySQL® Server and the HoneyMonitor Project.

HoneyMonitor is a MySQL® Administration and Monitoring Tool developed by HoneySoftware (yes.. yet another GUI tool for Windows® Systems, but with a really wide set of features, or at least.. I guess).

As regards the Server, I will try to post something that in my hope could be helpful for you. I usually test the new features of the Server (today, this means for example the storage engine FALCON and MARIA or the Cluster Disk Data) and sometimes I found bugs or I have enhancement requests.. thus, let’s talk!

As regards the Software HoneyMonitor, I will try to disclose the outcome of the new …

Bug#33184 looked like a tough nut to crack. The initial report was quite clear. Some tests failed on Mac OS X.

I initially assumed that our testing boxes did not include the platform I was using, and informed Hakan. He tested the suite on his box, and reported success.
Too bad. Being able to reproduce a bug is the first step towards its fix. So we exchanged notes on how we compiled the sources. It turned out that I was using the optimized build, while Hakan was using a build with debug options.
I tried with debug options, and indeed, the test suite passed. However, since users are likely to adopt the optimized build, the bug was still confirmed.
More time passed. Hakan made some changes, and the test suite passed in his box, but failed in mine.
Finally, Hakan found the problem. The test suite failed because of the default gcc compiler …

The Certified MySQL Associate exam is the entry level exam for those new to MySQL and it covers a lot of the basics. Sometimes the basics are so basic that they are not obvious.

Suppose you have a table with dozens of columns that has been in production for a period of time and you issue the statement 'SELECT * FROM long_used_table;'. What order will the records be returned from the server?

Well, it depends. And a second try with the same statement may give you different results. The rule is that there is not a guaranteed order. If you want the data in a specific order you need to add ORDER BY, i.e. 'SELECT * FROM long_used_table ORDER BY special_index;'.

Now, on the CMA exam you are ask about this guaranteed order (or lack there of) in a very explicit fashion. In the other exams, it is not as straight forward and you have better have that internalized when reading the question. And in 'real life', this …