Lately we saw many complains of how MySQL Config Wizard works.

Most of them are just special case of bug #42820 verified some time ago. I though it has trivial workaround, but one of users complained he read a lot of articles related to this bug, but nobody pointed the workaround.

So here you are: if your my.ini is broken after update, copy old saved configuration file (it should be file named my.ini.bak or similar in the installation directory) or fix new one manually, then don't run Config Wizard again, just manually start the service.

You may have noticed that videos around here have been getting higher and higher quality.

I don’t just mean the cool content from WordPress.tv, but the video player and video/audio quality itself.

We’ve rewritten how videos work here on WordPress.com from the ground-up and taken inspiration from the great products at Vimeo and Smugmug, and are pleased to formally offer our video upgrade to everyone. Here’s a sample of what it can do especially for those sweltering in the heat right now:

With the video upgrade (available on your upgrades page, bottom left of dashboard navigation) when you upload a video of almost any format we’ll crunch it into several different formats just right for streaming on the web, DVD quality, HD quality, and even optimized …

A year ago, the outline was being written. A lot of work was crammed into the intervening months, and I am happy and proud to announce that the MySQL Administrator’s Bible has been published, and is sitting on the shelf at many major booksellers already. The official publication date is today — Monday, May 11th, 2009 — although some stores have had copies for a week, including Amazon.com.

The MySQL Administrator’s Bible, published by Wiley Press (available on Amazon.com at http://www.amazon.com/MySQL-Administrators-Bible-Sheeri-Cabral/dp/0470416912/, fully covers how to administer MySQL 5.1. It is suitable for people new to MySQL, although as an experienced MySQL DBA I can say that I learned a lot while researching and writing this book, and I believe that even veteran DBAs can learn from this book.

This book for …

The first cut of a Java EE implementation of Olio is now checked into the repository. The file docs/java_setup.html gives instructions on how to build and setup this implementation. The implementation uses JSP, servlets, JPA for persistence, yahoo and Jmaki widgets for AJAX etc. The web application is located in webapp/java/trunk and the load driver, database and file loaders etc. are in workload/java/trunk.

Check it out.

We’ve had MySQL meetup’s organised thanks to mysql.meetup.com for years now, and its sad to see the relationship end in about a fortnight. Never fret, because it seems that Facebook can do all that, and more.

Migration

If you’re the meetup organiser, and you checked the Members list, or even attempted to download it, you’ll be disappointed. You get a CSV file, with the name of the person, some other metadata, if they’re on the mailing list (chances is yes to all), and the URL of the member profile. What’s missing? An email address.

So while its nice to have a CSV copy of the member list, it will not assist you in any migration, whatsoever. Totally data lock in :-(

Mailing list/message board

Keep in mind that you’ve got mailing lists and message boards on meetup.com. You’ll want to make use of this, to tell people to join your new Facebook group. Mailing lists are of the form: …

Profile Near-Linear Scale-Out for Aggregation

Calpont offers near-linear scale-out for aggregation behavior. To demonstrate, we have a set of queries that aggregate across 1, 3, 5 or 7 columns against an f_log table has just over 5.14 Billion rows, representing 140 days worth of web log data. The f_log table has 25 columns as created, but the queries use:

An 8-byte date range filter (hour_id)
Between 1 and 4 dimension keys (4-byte) (*_dim_id)
Between 0 and 3 flag/type attributes (1-byte).

There are 3 dimensions to this profile:
1) Scaling the group by operation across 1,3,5,7 columns. The queries touch 12, 17, 22, and 27 bytes per row.
2) Scaling the number of rows based on the hour_id filter (327 Million, 666 Million, and 1.09 Billion rows matching filters against 10, 20, and 30 days of data).
3) Scaling the Calpont Performance Module (PM) tier to add additional processing …

Scaling MySQL and ZFS on T5440

Solid State Disks : a 2009 fashion

This technology is not new : it originates in 1874 when a German physicist named Karl Braun (pictured above) discovered that he could rectify alternating current with a point-contact semiconductor. Three years later, he had built the first CRT oscilloscope and four years later, he had built the first prototype of a Cat's whisker diode, later optimized by G. Marconi and G. Pickard. In 1909, K. Braun shared the Nobel Prize for physics with G. Marconi.

The Cat's whisker diodes are considered the first solid …

Scaling MySQL and ZFS on T5440

Solid State Disks : a 2009 fashion

This technology is not new : it originates in 1874 when a German physicist named Karl Braun (pictured above) discovered that he could rectify alternating current with a point-contact semiconductor. Three years later, he had built the first CRT oscilloscope and four years later, he had built the first prototype of a Cat's whisker diode, later optimized by G. Marconi and G. Pickard. In 1909, K. Braun shared the Nobel Prize for physics with G. Marconi.

The Cat's whisker diodes are considered the first solid …

Victory!

Well sort of.

This morning I finally completed the loading of all of my books into LibraryThing.

The reason I started this project was to keep myself from buying duplicates (and to keep down the number of duplicates within my friend circle in general).

The problem is, most of the books I don't care about really. Other then graphic novels, the rest are for the most part paperbacks I just loan out. Some I get back, some I don't. I've given away scores of O'Reilly books and dozens of copies of a couple of other series. When I find some books for under a buck I just buy them so that I can give them out to others.

It is not like I own every book I have ever read.

What I would love to have is a dump of the database from my childhood libraries (or from the library in Iowa City, I …

Introduction

A question I recently saw on Stack Overflow titled Faster way to delete matching [database] rows? prompted me to organize my thoughts and observations on the subject and quickly jot them down here.

Here is the brief description of the task: say, you have 2 MySQL tables a and b. The tables contain the same type of data, for example log entries. Now you want to delete all or a subset of the entries in table a that exist in table b.

Solutions Suggested By Others

DELETE FROM a WHERE EXISTS (SELECT b.id FROM b WHERE b.id = a.id);

DELETE a FROM a INNER JOIN b on a.id=b.id;

DELETE FROM a WHERE id IN (SELECT id FROM b)

The Problem With Suggested Solutions

Solutions above are all fine if the tables are quite small and the …