Queue tables are used to take care of events. There is a mechanism that insert rows and another that takes care of the existing rows, usually deleting them at the end.
When possible one should use Oracle Advanced Queuing mechanism which takes care of managing the queue and a simple request will give you the next in the line.
Some applications develop their own queuing systems and it is a good way to learn how queue works.
Imagine a table with a list of elements and two specific columns:
- order of arrival
The first to be served is the one that, having the highest priority, was the first to arrive.(more…)