At Grazr, we store hierarchical data in MySQL. We have a query that I'm trying to optimize:

explain SELECT FROM child1 LEFT JOIN parent USING (fid) LEFT JOIN child1_text using (iid) left join child2 using (iid) where parent.indexed_varchar_col in ('abcd...', 'xyz123...' ) and (iid >= parent.iid_first) and (some_date <= now()) order by some_date desc

I get this:

*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: parent
type: range
possible_keys: PRIMARY,indexed_char_col
key: indexed_char_col
key_len: 96
ref: NULL
rows: 21
Extra: Using where; Using temporary; Using filesort

<3 more rows of explain, the same between two queries>

"Using temporary; using filesort" make this query much slower.

If I simply remove the order by: …

Today, I posted the solution (a sample project) for the NetBeans 6.0/6.1 Inserts Updates Deletes tutorial using MySQL.  I'll be posting solutions for other databases on this page.

This tutorial is a JSF application that demonstrates basic CRUD (create, read, update delete) operations on a database.
 

Today, I posted the solution (a sample project) for the NetBeans 6.0/6.1 Inserts Updates Deletes tutorial using MySQL.  I'll be posting solutions for other databases on this page.

This tutorial is a JSF application that demonstrates basic CRUD (create, read, update delete) operations on a database.
 

Yesterday's Los Angeles Times had an article about WikiMedia's financial difficulties. It's interesting to see that a professional core team is required to sustain even this uber-example of community volunteerism. This professional core team, in turn, needs to be paid, thus requiring a business model to sustain it.

So are we looking at a limit to what community volunteerism could achieve? Does this mean any large-scale effort would ultimately require a commercial aspect to stay relevant, as many open source projects have come to believe as well?

Perhaps in the end, none of us could ever escape the need to balance our social obligations with economic realities. Not that that is a bad thing: the whole point of a market-based economy is to allocate scarce resources, so that activities don't grow beyond what could be …

We’re pleased to announce that the Falcon beta is now out and available.  Falcon is MySQL’s new transaction storage engine, and offers a number of nice features for those developing applications that have transactional needs.  Falcon has all the standard transactional features you’d expect (ACID compliance, MVCC, crash recovery, etc) and some other items you will likely find helpful to have (user-defined tablespaces, SQL-based diagnostics for locking, I/O, and more.)

Please download the new Falcon beta (note that the Falcon beta is in the 6.0.4 alpha binary) and let us know what bugs you find or enhancements you’d like to see - your feedback is (as always) greatly appreciated! If you’re new to Falcon, you can check out the various tech white papers, getting started guides and FAQ’s on our 6.0 …

Eric Herman and Antony Curtis are hard workers. You don't see them bragging about this and that. They do long and thorough research, and then they prototype. At that point, they claim victory, and usually with reason.
Their work on stored procedures using external languages is one of the most refreshing pieces of new technology applied to MySQL since the announcement of MySQL 5.0.
If you are dissatisfied with the cumbersome heaviness of the standard stored routines, come …

A few months ago on planet-php.net, I came across funcaday, a wonderful idea “developed by self-proclaimed PHP guru Paul Reinheimer and Graphic Design lackey Courtney Wilson.”

Basically, funcaday is a run-down of PHP functions, with a short description and a few hints on how to use them. Having programmed PHP for about a decade, I can safely say that I feel pretty well-versed in the PHP universe. Still, I’ve had at least two “Aha!” moments in the time I’ve kept up with the sites’ RSS feed. I think this is a great idea, and believing that MySQL deserves something like it, I’ve decided to follow up with a similar “service” to those interested.

Since I don’t have a graphic designer handy, I guess …

Sheeri always amazes me. When I think that I have seen all it has to be seen in the field of databases, she will always come with some innovative way of looking at old things.
This session is a series of aha! ideas. Some of them can have come to you. You may have heard of some others, but Sheeri does not stop at that. When she hears about a promising practice, she digs in, until she gets all is there to be learned.
She's a captivating speaker. Once you attend one of her sessions …

(Credit: Mozilla)

I just downloaded Mozilla's Firefox 3.0 Beta 4, and loved what I saw:

See that? Firefox is localized into a wide range of languages, which is great. But what I appreciate even more is that it treats Windows, Mac OS X, and Linux as peers. In Microsoft's world, software runs solely or best on Microsoft's operating system, database, etc. Given the chance, most proprietary software companies behave like this.

Not Mozilla. Not Eclipse. Not Zimbra. Etc.

There's something about open source that speaks up for the potential user who isn't part of the mainstream. Somebody, somewhere, is like that person and has contributed the code to bring the outsider in.

...

As Matt reported last week, IBM announced that it was bowing out of the solidDB for MySQL project. "Those of you who know Solid's history know that Solid has long been a leader in the area of in-memory database software. This in-memory technology, and not Solid's open source offering, was the key driver behind IBM's acquisition. As a result, I regret to inform you that, effective immediately, we will not be continuing further development on solidDB for MySQL. solidDB for MySQL will continue to be hosted and available here at SourceForge, and existing releases will continue to be available under... READ MORE