Esri Press Books I've been reading & Float vs Double

It's been a while since my last post, I've been using twitter more and more, which means I've been posting less and less content and tips and tricks. I've been spending a lot of time messing around with Python (and after a few months of realizing I had the wrong installation of Python, I've now got my arcpy and other modules running smoothly) and relearning how to do things with modelbuilder.

I've started going through Getting to Know ArcGIS: Modelbuilder (http://esripress.esri.com/display/index.cfm?fuseaction=display&websiteID=195&moduleID=0) to help relearn and understand the things I've been doing for a few years. This is the first comprehensive text on modelbuilder I've seen and there is so much value in Iteration and a whole slew of other tools that would have helped my modelbuilder experiences earlier on.

I've also been reading Modeling Our World (2nd Edition): The ESRI Guide to Geodatabase Concepts (http://store.esri.com/esri/showdetl.cfm?SID=2&Product_ID=1247&Category_ID=56). This book is really great. It provides a great overview of GIS data and is a great all-in-one refresher. So I'm going to try and post more and more about the little things in ArcGIS.

Now, on to Float vs. Double.

So for a long time I've been defaulting to using Double because it allows for 16 significant digits. However, as I read in Modeling Our World, Float stores 7 significant digits and is half the storage space of Double. I usually use Double when dealing with decimals but after realizing that I'm essentially expanding all my databases, with sometimes many many fields, to be double (no pun intended) the size they need to be because often when I deal with decimals, 7 digits is more than enough. So by cutting down the size of my databases I will be reducing my storage footprint but also hopefully speeding up my processing time.

DUHHHHH.

So the takeaway should be, if you don't need Double, use Float.

"Floats use half the byte storage of doubles" - Michael Zeller, Modeling Our World

For more info on field types see:
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//003n0000001m000000.htm