Introduction

If you, like me, are building or thinking of implementing a MySQL-powered application that has any need for prioritizing selecting certain data over other data, this article is for you.

Example

As a real world example, consider a queue-like video processing system. Your application receives new videos and processes them. The volume of incoming videos can at times be higher than the processing rate because the process is CPU bound, so occasionally a pretty long queue may form. You will try to process them as fast as you can but…

Note that I am using a queue here, so the the next item to be processed is a result of sorting by some sort of field in a ascending order, for example ORDER BY id or ORDER BY upload_date. Iâ€ll pick the id sort here.

…suddenly, you need to process a video somewhere in the middle of the queue or an important video enters and …

“The question is not why use open source, but how to best use open source,” wrote Matt Asay earlier this week. It was a throwaway point but one that I think deserves more attention.

It occurred to me that “how” rather than “why” is the most significant question that open source vendors and projects should be answering right now as they try to encourage greater adoption of open source software.

There can’t be a CIO or IT director left on the planet that hasn’t either asked or been told why they should deploy open source software. They are either inclined towards believing the claims of theoretical benefits or they’re not. How many have asked or been told how they can take advantage of open source software?

Certainly those that are convinced or intrigued by the potential benefits will have gone on to explore …