I've accomplished quite a bit in the last week.
On top of my day job, I cleaned out my basement, fixed my car, and got Xen working on my server.

As for the project, I feel I have a solid understanding of how the current cache works and exactly what needs to go into the interface. I'm a bit worried about the invalidate_by_MyISAM_filename stuff because I'm not familiar with the storage engine code, but everything else appears to be smooth sailing.

I've solved the interface problem I was researching: by avoiding it completely.
An interface in comments alone is sufficient at the moment with only two cache backends, a simple #define can switch them at compile time without any performance hit. This can fairly easily be improved upon by future developers so long as I document appropriately.

I've got a skeleton Query_memcache class going with all the necessary methods defined and commented with …

MySQL’s TRUNCATE statement will evolve over the next few years, as we fix bugs or strange behaviours, and as we try to make storage engines more consistent with each other. Equally interesting are the aspects that will remain the same, as we confirm that our behaviour conforms to standard requirements.

Define TRUNCATE

TRUNCATE T has two definitions:
(1) it means “delete all rows in T”, as the MySQL Reference Manual says in section “TRUNCATE Syntax”. (2) it means “drop T, then create it again”, as the Reference Manual says later on. The better definition is (2). I have proofs.

Proof #1: The required privilege for TRUNCATE is DROP.

Proof #2: TRUNCATE does not cause activation of DELETE triggers. For example:
CREATE TABLE t (s1 INT);
CREATE TRIGGER t_ad AFTER DELETE ON t
FOR …

Hi !

The 2nd Weekly Seminar was held on June 6 in MySQL Seminar Room.  The seminar was divided into two parts and focused on MySQL products in terms of both technical and business.

Introduction of MySQL Enterprise products

In the first half of the seminar, Kajiyama, MySQL Technical Evangelist, introduced “MySQL Enterprise” of one-year subscription which includes “MySQL Enterprise Server” that has been improved by many additional tests, “MySQL Enterprise Monitor” that enables to monitor multiple MySQL servers from a single console, and technical support and knowledge base of more than 2000 technical articles.

Also, demonstrating the Enterprise Monitor, Kajiyama explained how to use and customize advisor functions which help you handle in the event of a trouble.

…

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.

Its facinating to see what a couple of years development and bugfixing work upon MySQL has unwittingly done to the free space on my main G5 PowerMac at home. I have captured a screenshot from GrandPerspective and as you can see, the largest file on my hard disk is the MirrorAgent.crash.log file, and all those pretty blocks on the left hand side of the window: They are all coredumps. A few swift

Databases are used by many different disciplines, from your DBA to your Developer, right down to the End User. They can also be viewed from many different perspectives…

DBA’s are usually interested in the server configuration, index usage etc. Developers however are often concerned with retrieval methods, datatypes and occasionally stored procedures. One thing is for sure, your database if used effectively will be changing frequently, and with so many people accessing your database do you know what the last change was? Would you know if someone added an index to a table? (would you care… )

Revision Control is often used to track changes to source code and other documents, so why not your …

I was thinking of this and could not figure it out or maybe I am just confused... Hehehe.

If MySQL is lagging behind the master (7,000 secs.), would it be caused by the I/O thread being slow or by the SQL thread (of course, this is assuming that I only have these two options to choose from)? If it is the I/O thread, what should I be looking for?

I've always assumed that the I/O thread would not cause a huge replication delay as it is just reading the binary logs from the master. So, if the Master_Log_File and Relay_Master_Log_File are the same and the Exec_Master_Log_Pos and Read_Master_Log_Pos are the same too, then I can assume that the replication delay is not based on the I/O thread, right?

And does anyone know how to compute the Seconds_Behind_Master???

The session has been recorded. The webex file and the webinar are available here.

Here is the Q&A session, with more detailed answers.

Q from Tomasz: You said memcached is integrated with, among others, MySQL. Did you mean integration by e.g. php or direct, automatic integration?
A: Memcached API are available for many enviroments, such as Php, Perl, C/C++, Rails etc. With MySQL, you can use UDF functions or a storage engine. Both are community projects.

Q from Juan: memcached: Facts data size up to 1MB? What size, i dont understand!
A: It's the size of an item associated to a key. When you store an element (item) into memcached, the size of the key is max 250 bytes and the item is max 1MByte.

Q from Frederik: Do memcached save data in RAM or disk?
A: It is RAM …

On January this year, I decided it was time to get a new computer. May be catch a boxing day deal. After choosing a nice quad core with 4 GB of RAM, I realize one 'small' problem with this Dell: it comes with Vista. Any other options for the OS? Nope, it's Vista or Vista.

If, at the time, I had not had previous experience with Vista, I would've been happy to get it. But another box I had bought for the living room came with Vista, so I knew it.

And this is what was in my mind: Vista can make my new Quad core run like an old XT 8088. I won't even notice that I have 4 GB of RAM, Vista will swallow it whole with nothing left for me to run vi. It is big, and it is slow.

Next is the stability. I saw Vista crashing too often. The file explorer at least once a day.

So, as I was looking at the checkout screen of the Dell site, instead of having a nice picture of productivity and speed, I could see only dark Vista …

On January this year, I decided it was time to get a new computer. May be catch a boxing day deal. After choosing a nice quad core with 4 GB of RAM, I realize one 'small' problem with this Dell: it comes with Vista. Any other options for the OS? Nope, it's Vista or Vista.

If, at the time, I had not had previous experience with Vista, I would've been happy to get it. But another box I had bought for the living room came with Vista, so I knew it.

And this is what was in my mind: Vista can make my new Quad core run like an old XT 8088. I won't even notice that I have 4 GB of RAM, Vista will swallow it whole with nothing left for me to run vi. It is big, and it is slow.

Next is the stability. I saw Vista crashing too often. The file explorer at least once a day.

So, as I was looking at the checkout screen of the Dell site, instead of having a nice picture of productivity and speed, I could see only dark Vista …