Fabulous... thanks for pointing out that link. So, take a look at this http://geology.com/usgs/geologic-time-scale/, or, specifically, at the image at http://geology.com/usgs/geologic-time-scale/geologic-time-scale-one-column-cropped.gif. Now, imagine you have a rock that is estimated to be from between 25 Ma (million years ago) to 20 Ma. So, it started in the Oligocene and ended in the Miocene. The Tertiary period is the "closest" period that completely encompasses the sample rock. So, I want to model the following --

given a point in time or a duration of time, find the closest period that completely encompasses your sample.

Right now we are storing these "periods" with there start and end times in a SQL table, and then doing a lot of nested SQL queries to return our results. I am trying to determine if there are better ways to model such relationships. Intuitively SQL seems wrong for this.



when small people start casting long shadows, it is time to go to bed

In reply to Re^4: modeling overlapping generations by punkish
in thread modeling overlapping generations by punkish

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