One of the strengths of mondrian's design is that you don't need to do any processing to populate special data structures before you start running OLAP queries. More than a few people have observed that this makes mondrian an excellent choice for 'real-time OLAP' -- running multi-dimensional queries on a database which is constantly changing.

The problem is that mondrian's cache gets in the way. Usually the cache is a great help, because it ensures that mondrian only goes to the DBMS once for a given piece of data, but the cache becomes out of date if the underlying database is changing.

This is solved with a new set of APIs for cache control in mondrian-2.3. Before I explain the API, let's understand how mondrian caches data.

How mondrian's cache works

Mondrian's cache ensures that once a multidimensional cell -- say the Unit Sales of Beer in Texas in Q1, 1997 -- has been retrieved from …

I'm starting to get into Django more and more, forgetting PHP. And some nice stuff is coming up.

Yesterday there was a post about a Django Cheat Sheet published by folks at Mercurytide. Still work in progress, but all tools are welcome for a 'starting' project.

And then there is the Django Book. It's getting quite heavy already in pages and you can leave comments to make it even better!
Of course, there are the usual PostgreSQL posts.. Well, they are funny. Like the one on Chapter 2 suggesting to indeed sort the database engines alphabetically because they should be equally good, but keep PostgreSQL first in the list.

Other comments suggest the MySQL python module MySQLdb doesn't work with Python …

I'm starting to get into Django more and more, forgetting PHP. And some nice stuff is coming up.

Yesterday there was a post about a Django Cheat Sheet published by folks at Mercurytide. Still work in progress, but all tools are welcome for a 'starting' project.

And then there is the Django Book. It's getting quite heavy already in pages and you can leave comments to make it even better!
Of course, there are the usual PostgreSQL posts.. Well, they are funny. Like the one on Chapter 2 suggesting to indeed sort the database engines alphabetically because they should be equally good, but keep PostgreSQL first in the list.

Other comments suggest the MySQL python module MySQLdb doesn't work with Python …

Inserting bullets into slides where previously there were none. Thanks OOo, reformating a number of slides was exactly what I was missing in my life.

Oh, and waiting an entire minute to save my presentation is also a great use of time. Funnily enough, my laptop disk (although slow) is faster than 1.3MB/minute.

An addition to The Long Tail of “The Long Tail” related blogs

The Long Tail effect of open source has been discussed in several contexts. Some of the interpretations are likely very different from what Chris Anderson intended, but more and more niche needs of a relatively small set of people (which don’t have economies to justify product development by proprietary software companies) are being met by open source software. Witness more than 140,000 projects registered on SourceForge.

Whenever I install Red Hat Linux I am amused by some of the choices available for the language of the operating system - what is different when running a Red Hat box with English(Singapore) vs. English(India)!? It is also heartening to see support for regional languages making computers accessible to even remote villages (which don’t provide economic motivation to proprietary OS providers).

The long tail effect of open source …

Last week I and Monty gave a short talk at the MySQL Lead's Meeting in Stockholm on "How to review a bug".

I converted the talk over to a PDF file for those who are interested:
http://krow.net/images/howtoreviewabug.pdf

Here is the outline:

Bad Ideas
Suggest to run --record for mysql-test-run for anything that breaks.
Disable Tests within a Bug Fix.
Both Fix bugs and clean up code in the same patch.
Ignore new code that you don?t understand during a review.
Discourage developer from writing test to prove that the bug was fixed.
Prefer changes that require huge changes to all tests, they were probably broken.
Never ask from help from the developer who wrote the original code.
Methodology
Read bug report, find out what user?s problem was, and read the description of …

All -

The Falcon team has just posted a new Alpha release of the new Falcon transaction storage engine. The 5.2.3 release contains a number of bug fixes, performance enhancements, and can be downloaded on the 5.2 download page.

In addition, part two of my article series on Falcon has just been posted to the Community Articles page on the MySQL web site. I cover how Falcon performs transaction management, how concurrency is handled, and finish with an interesting example of how fast Falcon can accomplish rollbacks when they’re needed. Be sure to check it out and be looking for part three, which will be coming soon.

Thanks for your continued support and be sure to drop me a line and let me know what you think of Falcon.

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MySQL will go public. Would you buy stock if you had the money? Why or why not?
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Episode 8 Show Notes:
This episode’s feature is basic MySQL Security. Not only will we discuss what the basic security is, but we’ll discuss the *why*s, not just the how’s.

Direct play this episode at:
http://tinyurl.com/2r9kom

Subscribe to the podcast by clicking: …

We've all done it but possibly not on this scale. Someone may have forgotten a WHERE clause when a bank customer received 75000 bank statements. At 27 pence per letter, that cost about £20000 (US$40000) just for postage. Unfortunately, it wasn't an isolated incident. In the same fortnight, the UK Government managed to fubar a mail merge to 26000 pensioners. In both cases, quality control seems to be evaded or absent.

ID Integrated Data SA situated in Petit-Lancy,Geneva, is further demonstrating its confidence in open source solutions by signing a training partnership agreement with MySQL AB, the developer of the popular database software.