AnsweredAssumed Answered

Using Selection Tools and "Make Feature Layer" Effectively and Efficiently

Question asked by EHRobinson on Feb 1, 2013
Latest reply on Feb 4, 2013 by EHRobinson
Greetings,

I have a few questions regarding the use of the selection tools (both by attribute and by location) and how they interface with the ???Make Feature Layer??? tool, specifically as they work to prep the output of one tool for the input into another.
As I understand it, there are two major ways to make a selection by attribute:

Select: Extracts features from an input feature class or input feature layer, using a SQL expression and stores them in an output feature class.

Select Layer by Attribute: Adds, updates, or removes a selection on a layer or table view based on an attribute query.

There is one tool for making a location based selection:

Select Layer by Location: Selects features in a layer based on a spatial relationship to features in another layer.

But then there is also the Make Feature Layer Tool

Make Feature Layer: Creates a temporary feature layer from an input feature class or layer file and can evaluate an SQL expression when creating the layer.

Here are my questions:

1. Since attribute based selection has two different tools (one to extract the result and one to just select the result) why isn't that duality mirrored with the location based selection?

2. If the ???Make Feature Layer??? will make a selection based on a n SQL query, then how does it differ functionally from the ???Select??? tool (other than it creates a temporary layer)?

3. Originally, I thought that I would need to pass the result of a selection operation through the ???Make Feature Layer??? tool only if I had only made a selection in a layer and not also extracted it. But this is not the case. Even after running the ???Select??? tool which should extract the selected objects, I still have to pass the result through the Make Feature Layer tool in order to prep the result to be an input for another tool.

4. Generally speaking, what do you really need to know to make sure that the tools are being used most efficiently in a geoprocessing workflow? For example, in the ModelBuilder workflow I have shown below, I am having to do a lot of selection and then making feature layers in order to prep for the next tool, resulting in many more operations that I think are necessary, and an inefficient workflow. Is there a way to eliminate redundancy in the flow? Or is this just the way it has to be done?

Thank you so much for any help you may be able to provide?

Attachments

Outcomes