Using callstacks to look at code is very useful. If you are not familiar with callstacks, I suggest you read my earlier blog about it. I was trying to understand the mysql code path using sysbench as the test and found something interesting. An image of the callstack is shown below. The SVG version, with much more information, is also available . The width of the block is proportional to the time it took for the function, and the height is the level (or depth) of the stack.

Mysql uses mysql_execute_command() to execute queries. Looking at the callstack you can see very clearly that mysql_execute_command() calls open_and_lock_tables which then tries to open tables via open_table(). The code path gets interesting here. As you can see in …

Of all the practical jokes on April Fool's Day, only one actually got me. Yes, Ronald Bradford's post yesterday describing a visa situation and having to return to Australia actually got me looking up immigration attorney numbers in the US that could help as well as emailing him my heartfelt sympathy about his situation. I even started planning for who might replace him at the MySQL Conference, as it sounded like he was not going to be there.

In response to my email, he wrote back:

April Fools Dude!

to which I wrote back:

Oh, you totally suck.

So, Ronald, you have the dubious honour of duping me (among others, I see). Congrats!

Today, we run into an issue when a client of ours. They wanted to see some of the data on our website and when doing a search, they didnt see all the days they asked for in the search

Why didn't they see all the data? Because they did a search by date and some of the dates were stored via the website in the form of '2008-01-01 00:00:00' and some were stored via the database in the form of '2008-01-01 12:35:49'.
Now, for some magical reason, if you hide the time in the date in your searches, like so:
where signupdate between '2008-01-01' and '2008-01-02'
or
where signupdate between date('2008-01-01 00:00:00') and date('2008-01-02 00:00:00')
then you might not see all the data between the days 01 to 02.
Depending on which way your date was stored, you might only see the dates between those 2 dates and not equal to those dates as well.

So for example, if you had:

…

So, I’m a little late to the game reporting this. Key folks from MySQL (my former company) invaded Sun Microsystems (my new overlords and masters ) yesterday with hundreds of Dolphins as part of an April Fools stunt to say hi to all our new co-workers at Sun in Menlo Park. Zack Urlocker and Marten Mickos appear in this very geeky video now available on YouTube. Yes I work with and for a very geeky group of people

To see the fishy results and the porpoises in question, check out the rest of the photos that Zack also put up.

With the advent of fast and reasonably sized SSD drives, I have to admit that even I, as one who still thinks the standard hard-drive tends to be a better choice, am warming up to solid-state. One crazy benchmark I have always wanted to do is how using consumer flash cards (SecureDigital, CompactFlash, etc.) stack up to their dedicated drive brethren. I just noticed that you can now buy off-brand 4GB High-Speed SD cards for around $10. That is amazingly impressive when you consider, even a few months ago, how much 4GB cards cost. After doing a bit of math, the economics work out pretty well. To match a 64GB SSD drive in capacity, I need 16 4GB SD cards. At $10 a piece, that's only $160. That's a pretty cheap way to match the capacity of an SSD drive without the cost.

Of course, there's a huge catch, or everyone would likely already be doing this. Actually there are quite a few. The numbers I ran don't include the cost of USB card …

A gentle reminder: next week, there will be two more stops of the MySQL Meetup Mashup Tour:

• Monday, April 7th, 19:00: Hamburg, Germany. We will meet in the meeting rooms of the local Sun Microsystems offices ( Nagelsweg 55, 22097 Hamburg). There will be two technical sessions: Giuseppe will talk about the MySQL Sandbox, Kay Koll will give a presentation about how to combine MySQL with OpenOffice.org. He will also describe the new report generator and give an overview over the future of OpenOffice. You can register for this event via meetup.com or …

If you've been following his blog, then you will already know that Ronald Bradford has joined PrimeBase Technologies. We are very pleased to have him on board! As many know, Ronald has always been very active in the MySQL community as far as his job has made this possible.

Ironically during his time at MySQL he was less present in the community than before. When we discussed our plans for PrimeBase with him, Ronald was interested because it was an opportunity to return to a more active role in the community. I am very glad that this motivation was understood by almost everyone at MySQL and we are all looking forward to seeing and hearing more from Ronald.

But, of course, Ronald is not "just a pretty face" ;) He will be helping us to design and specify our open source products (including …

Read more about the April Fool pranks played at Sun over past years.

Technorati: aprilfool mysql jonathan sun

Today I started my new job at PrimeBase Technologies. The company that has brought you the PBXT and Blob Streaming Pluggable Storage Engines for MySQL 5.1.

My move to Germany has gone mostly without incident and now I’m settling in to different weather, language and food, plus the change in time zones +6 hours.

A smaller company from my previous, but I’m part of a larger group then expected. One of 26 people in the office. It’s good to have a desk, a big monitor (and definitely not a German keyboard) and see and talk to people on various topics and interests in comparison to either past work at home by myself, or on a new customer site each week during my consulting days.

Preparations for the upcoming …

MySQL Proxy allows you to execute multiple queries, by inserting them into the query queue.
What happens if one of the queries in the pipeline generates an error?
If you don't handle this occurrence, the Proxy will continue sending to the server all the queries in the pipeline, regardless of the result. It's easy to understand that, if the second query depends on the execution of the first one, checking the result of each query is essential.
We know already how to return an error. We only need to apply that knowledge in the right place.
The read_query_result() from the previous …