I am indeed amazed when I consider how weak my mind is and how prone to error --Rene Descartes

This is not a recommended approach; only explained here so that you can identify it when it presents itself and avoid it.

The following indexes are created on the star schema example shown before:

1. Concatenated index is created on the fact table: sales_transaction (transaction_detail_key, product_key, sales_org_key, calendar_key) - note the difference, compared to the nested join approach where multiple indexes on each foreign key were created
   
2. In addition some indexes may be created on the dimension attributes that are frequently queried: transaction_details (transaction_type), product (SKU), sales_organization …

One cannot have everything the way he would like it --Mark Twain

In the absence of other advanced techniques for star join optimization, nested fact join with dimensions while ensuring that the indexes are used for each dimension join delivers reasonable performance.

The following indexes are created on the star schema example shown:

1. Primary key unique index on surrogate key for each dimension. One index each is created on: calendar (calendar_key), transaction_details (transaction_detail_key), product (product_key), sales_organization (sales_org_key)
2. One index is created for each foreign key on the fact table: sales_transaction (calendar_key), sales_transaction (transaction_detail_key), sales_transaction (product_key), sales_organization (sales_org_key)
3. In addition some indexes may be …

Lookup tables contain, in general, a fixed list of data. This data doesn?t change very often in database business applications. Examples of this data could be a product list, category type, supplier list, state name, zip code, phone area code, etc. In Windows and Internet web business applications, most of these lookup tables are graphically implemented by using ComboBox, ListBox or CheckListBox read-only controls. These controls are loaded with data using two main columns, ID and Name. For example, the USA state table, the ID could be ?CA? and the Name ?California?. Some times, for standard Windows form and Internet web page we need to show data to the end-users from many of these lookup tables. A fast data loading process and defining the main column values for each lookup table is required. In this article I will show you standard lookup data loading procedure and the generic classes object to store and read-only the values of the ID and Name …

Since our goal is to find a tool for profiling while we don't want to change/modify the existing code. So we chooses the Aspect-oriented C tool as the profiling language.

The basic idea is to maintain the profiling code separately, and then use Aspect C to weave the code into the original code automatically. For instance, if we are going to profile the I/O function pread, we can write the below code according Aspect specification. Then every time when pread is called, it will be executed.

#include
long pbxt_profile_pread_access_time;
long pbxt_profile_pread_freq;

int around(): execution(int pread(...)) {
struct timeval start_time;
struct timeval end_time;
gettimeofday(&start_time,NULL);

int val = proceed();

gettimeofday(&end_time,NULL);
…

It has gotten a bit quiet around the MySQL Proxy over the last weeks, but I can assure you it was worth it.

Here in my hands I hold MySQL Proxy 0.5.0. Not just some binaries, no everything with sources. As always it is dual licensed under the GPL and commercial MySQL license. We worked hard to get everything ready for the release: the wiki, the forums, the public SVN trees ...

The proxy can do magic. Put in your ideas and say the magic words and there ... it works. :)

The proxy is fully scripted now which opens up the proxy to your ideas. The possibilities are endless. I can think of at least of the following features:

• load balancing
• fail over handling
• query analysis
• SQL macros
• query rewriting
• .... much more

The proxy started as side project of me and is now evolved into a full MySQL project maintained by the …

After years of "No Call for Papers", and "How can I speak at Fosdem ?"

Now you can suggest speakers and subjects for the 2008 Fosdem edition so let's all fill in what we want at next years edition !

But what do we want, I guess we want a Scale the Web2.0 track with talks on MySQL , Apache, Loadbalancing, System Automation etc., don't we ?

This will be my last entry for a few days (probably more like a week).  I'm the scoutmaster of troop 440 and we're attending summer camp next week so I will not have much time available to email and blogging.  However, KISS #5 happened last night while I was activating my kids Vista computer.

The whole idea is that any message, error or otherwise, needs to be understandable by the average user.  This is the main reason why Linux will not get any serious traction on the desktop.  The gear heads that use it can't stand to dumb down the interface of their baby and the current Linux desktop experience is just to complex.  If the user has to know what a swap partition is or that a file named ifconfig even exists, then it's too complex.  But I digress.

So last night Katie (my daughter) tells me that her computer is broken.  Thinking that's odd since I just built it, I asked her what it's doing.  She …

jay pipes started with his five mysql wishes, and others have chimed in. i guess i may as well take a whack at it.

1. connect by. yeah, yeah. it?s not standard. i don?t care.
2. expose character-set conversions in the client library. all the code to convert between all of the character sets understood by the server is there, there?s just no public interface to it.
3. online backup. it?s in progress, but this will make things so much better in so many ways. we could actually have reliable backups of bugs.mysql.com. and it?s going to make starting up new slaves so much easier in replication.
4. re-learn how to ship software. the long …

I am subscribed to the memcached list. Memcached use (and interest in caching in general) has exploded it seems in the last couple of years. There are a lot of people that join the list that not only don’t have a lot of experience with memcached, but they don’t have experience with caching. We have been caching at dealnews since the beginning. We started using memcached at dealnews in early 2005.

One common concern that new users have is data not being updated the second it goes in the database. This is how it worked before they were caching. They are used to it working that way. So, when they start caching, they miss that instant gratification. We went through this at dealnews. Our content team could write a deal, go to the front page and see it right then. They could then move on with their lives. As we grew and it became apparent …