It appears "in_memory" is not really in memory.

DougMcGeehan

I have ArcCatalog 10.0 from the ArcGIS Desktop 10 SP4 suite. Just now, I pulled up the interactive Python window to test some code out in the application's interpreter.

>>> result = arcpy.CreateFeatureclass_management(out_path="in_memory", out_name="in_memory_junk")
>>> type(result)
<class 'arcpy.arcobjects.arcobjects.Result'>
>>> print str(result)
<Result 'C:\\Users\\DMCGEE~1\\AppData\\Local\\Temp\\2\\j6cc4de20957342a3aa8cda7d65b8cc7a.gdb\\in_memory_junk'>

I wasn't expecting to see the result of CreateFeatureclass to reside a temporary file geodatabase in the C:\Users\DMCGEE~1\AppData\Local\Temp\2\ directory. However, it's there, as indicated in the screenshot below.

[ATTACH=CONFIG]15140[/ATTACH]

I realize the documentation for in-memory workspaces indicates that "when data is written to the in-memory workspace, the computer's physical memory (RAM) is consumed", but the fact that the temporary file geodatabase is located in a temporary directory makes me think otherwise.

in_memory.png

Viewshed.png

image.png

MarcoBoeringa

Are you using Background Processing?
Processing in the background means sending the features you want to process over to another process and then getting a result back.
Because its another process we have to persist them to disk for ArcMap to read them on the way back.

Why o why didn't ESRI document this crucial factor in getting in_memory to work in the Help file???

I really can not find it in the main in_memory Help topic. This issue regarding background processing should be added under the "The following considerations must be made in deciding to write output to the in-memory workspace" text line. I have been struggling with this issue too.