Divide and Conquer --Gaius Julius Caesar

Table partitioning in data warehouses is used to divide a large database table into smaller physical tables called partitions1 that are easier to manage. The partitions still retain a single logical view for the user query execution. Range partitioning by date facilitates historical ETL processing and trend reporting:

1. ETL: Only current partition is impacted for load and index rebuild, the downtime is minimized as new data is rolled in while old data is rolled out
   
2. Querying and Reporting: Only relevant partitions are read based on the query's where clause, there is a significant improvement in response times
   

ETL

In a properly designed star …

This package is one of the many parts of the JasperSoft BI solution. I'm currently evaluating the JasperServer and below are my comments.

1. The documentation for JasperServer is terrible. Unlike other documentation which assumes that you don't know anything, JasperSoft assumes you know their stuff already. Because of this, it is quite hard to understand.

2. iReport which is the GUI interface to create JasperReport looks cool but I can't seem to get it working with JasperServer. Again, because of poor documentation or none at all. Oh wait! There is documentation which I think can be found in the 'JasperServer Ultimate Guide' which you have to buy for $50. Hmm, maybe a good way to make money for open source company. Create a nice looking open source software, but sell the documentation. Sweet!

3. I almost forgot this... when I was installing JasperServer, typically you would expect that if you have an …

The Economist makes three technology predictions for 2008, two of which concern web surfing and the third of which concerns everyone, whether they surf the web or not. The Economist's third prediction is that the technology world will open up:

The embrace of "openness" by firms that have grown fat on closed, proprietary technology is something we'll see more of in 2008....

Pundits agree: neither Microsoft nor Apple can compete at the new price points being plumbed by companies looking to cut costs. With open-source software maturing fast, Linux, OpenOffice, Firefox, MySQL, Evolution, Pidgin and some 23,000 other Linux applications available for free seem more than ready to fill that gap. By some reckonings, Linux fans will soon outnumber Macintosh addicts. Linus Torvalds should be rightly proud.

What's most …

This is a follow-up piece to an earlier rant:

We are hitting a few walls with a CouchDB deployment and both Damien and I are a bit puzzled. This posting tries to attract someone with a clue to help us out. Our problems might result from not understanding the documentation correctly, but with evidently inaccurate material, we stand little chance

Long story short: We’ve got it all sorted out.

Memory Hogging Spidermonkey

Sam Ruby relayed a hint by “a Mozilla Developer”. Invoking Spidermonkey with the -b parameter and a value of 1000000, we are able to keep the memory footprint constant. We haven’t measured how this impacts performance, though.

Crashing …

This is a follow-up piece to an earlier rant:

We are hitting a few walls with a CouchDB deployment and both Damien and I are a bit puzzled. This posting tries to attract someone with a clue to help us out. Our problems might result from not understanding the documentation correctly, but with evidently inaccurate material, we stand little chance

Long story short: We’ve got it all sorted out.

Memory Hogging Spidermonkey

Sam Ruby relayed a hint by “a Mozilla Developer”. Invoking Spidermonkey with the -b parameter and a value of 1000000, we are able to keep the memory footprint constant. We haven’t measured how this impacts performance, though.

Crashing …

This is a follow-up piece to an earlier rant:

We are hitting a few walls with a CouchDB deployment and both Damien and I are a bit puzzled. This posting tries to attract someone with a clue to help us out. Our problems might result from not understanding the documentation correctly, but with evidently inaccurate material, we stand little chance

Long story short: We’ve got it all sorted out.

Memory Hogging Spidermonkey

Sam Ruby relayed a hint by “a Mozilla Developer”. Invoking Spidermonkey with the -b parameter and a value of 1000000, we are able to keep the memory footprint constant. We haven’t measured how this impacts performance, though.

Crashing …

I was browsing around the web and ran across this article at xml.com, XML Moves to mySQL. Being a heavy XML user, I had to read the article. It looks like MySQL is expanding the built-in support for XML.

This article isn't very detailed but it links to Using XML in MySQL 5.1 and 6.0 at mySQL.com which is very detailed.

I like the ability that is built in to support loading XML from files. That's a feature I wish Oracle would work on. Even in 11g, that functionality is still limited.

MySQL also adds ExtractValue() and UpdateXML() support. If you're manipulating XML much, you know that these two functions are needed.

From what I know of MySQL and what I read here, MySQL is just getting started …

In the last round I wanted to replace everything with a lua implementation. Today, I want to take a step back and only replaces the autotools :)

On one side this follows the idea of cmake a bit more and on the other side it takes in account that make is isn't the evil guy here. Let make do the make job, let lua generate the makefile.

Ok, to put it in other words: we don't care who is building our code in the end. May it be Prime Mover, gnu make or nmake on windows.

It turns out that this task is more tricky in the end. Especially if you are crazy and want to build it Makefile.am files. Yes, the Makefile.am from automake as input to generate the Makefile. For now I go the route of a central Makefile that has everything (somewhat following the "Recursive Makefile considered Harmful" paper).

Let's see how much this hurts.

With new versions of XAMPP for Windows, Linux and Mac OS X we wish you all a merry christmas, snow on your server farm and a warming processor in everyones heart!

In all three Xmas gifts we updated MySQL to 5.0.51, PHP to 5.2.5 and phpMyAdmin to 2.11.3. But we didn't update Perl because the new 5.10.0 seems to be a development version, and in XAMPP we only support "stable" versions.

Santa Downloads and more details on the specific platform's XAMPP project page.

I'm getting in early, I had just started building my benchmarks for my talk on Amazon EC2 at the MySQL Conference and Expo next year when I discovered exactly why they say you need to run a test more than once; results can be completely unpredictable. Take for example the Sequential I/O performance on EC2, versus my home machine:



The first 3 tests were a 36G Seagate Raptor 10k RPM, a 160G Seagate SATA2 7200RPM, and a 320G Seagate IDE 7200RPM disk, running in the same machine I had at home. The last three were Amazon EC2 images. A few observations from these results:

• The char write test seems to max out my CPU (not on graph - see raw data), so that probably explains why it's consistent across all disks.
• My home machine is almost dead on consistent, whereas Amazon EC2 looks more like a roller-coaster
• The …