The Awaggregator
Tom asks: What sites like digg/reddit/techmeme do you use that you find truly useful and pleasant to use?
If you like digg, reddit and techmeme, you will most likely find the following useful and pleasant to use:
popurls is the dashboard for the latest web-buzz, a single page that encapsulates up-to-the-minute headlines from the most popular sites on the internet.
The main purpose of the site is to provide a quick glance on what’s happening without using your desktop/web RSS reader. New headlines (since your last cookied visit) come in pretty red, visited ones are grey.
Original Signal currently aggregates the 15 most popular sites in each of the following categories: Web 2.0, Tech, Gadgets, Jobs and Buzz. They even have a Most Popular page, and a very nicely aggregated Digg page.
I like these sites, they give you an instant overview of what’s buzzing on the net right now. It’s even very easy to create one of your own.
Filed in Interesting Stuff, Technology with Comments Off | Tags: aggregate, aggregatorUser-Defined Aggregate Functions
I had a requirement to write a query that should return a concatenation of column values from different rows and grouped by another column. Well, that would be easy if Oracle provided an aggregate function similar to SUM or COUNT for example, but instead of summing or counting, it would concatenate. Alas! There is no such pre-defined function in Oracle. But, don’t despair. Oracle has something called user-defined aggregate functions, meaning that you can define your own aggregate function, or even change the behavior of a pre-defined one such as MAX, MIN, SUM.
User-defined aggregate functions are used in SQL DML statements just like Oracle’s own built-in aggregates. Once such functions are registered with the server, Oracle simply invokes the aggregation routines that you supplied instead of the native ones.
User-defined aggregates can be used with scalar data too. For example, it may be worthwhile to implement special aggregate functions for working with complex statistical data associated with financial or scientific applications.
User-defined aggregates are a feature of the Extensibility Framework. You implement them using ODCIAggregate interface routines.
For more information see chapter 11: User-Defined Aggregate Functions in Oracle9i Data Cartridge Developer’s Guide.
Filed in Oracle with 3 Comments | Tags: aggregate, function, user-defined
