At the Forge - Shoehorning Data into a Database
Not all data fits cleanly into two-dimensional tables. When this occurs, you can try to shoehorn your data into an inappropriate container. Or, you can try to use the help that is built in to one or more levels of your software stack. If you use PostgreSQL, inheritance can be really useful. If you use Rails, you can take advantage of polymorphic associations, allowing you to treat two or more models with a common API as similar. This isn't the sort of thing you'll do each day, but it's a useful skill to have on hand for cases when you need to take unusual data.
To learn how PostgreSQL allows for inheritance, read the on-line manual at www.postgresql.org/docs/8.3/static/ddl-inherit.html.
Rails Cookbook, by Rob Orsini, and published by O'Reilly, has some good information about polymorhphic associations.
The Rails Wiki has some good examples and descriptions of polymorhphic associations at wiki.rubyonrails.org/rails/pages/UnderstandingPolymorphicAssociations.
Reuven M. Lerner, a longtime Web/database developer and consultant, is a PhD candidate in learning sciences at Northwestern University, studying on-line learning communities. He recently returned (with his wife and three children) to their home in Modi'in, Israel, after four years in the Chicago area.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
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With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide