Hello, We have an interesting situation, here, and I can't seem to put my finger on what's going on. Let's say I have two different classes of objects being cataloged. The first class, Class A, has a floating point attribute myFloat. The second class, Class B, does not. 'myFloat' is an index in the Catalog. Let's say the makeup of class instances in the catalog is 50/50 Class A and Class B: Instance1 (Class A): myFloat = 0.5 Instance2 (Class B) Instance3 (Class A): myFloat = 0.65 Instance4 (Class B) Instance5 (Class A): myFloat = 0.55 Instance6 (Class B) I queried the catalog with: Catalog(myFloat=0.0, myFloat_usage='range:min') Expecting to get record objects representing: Instance1 (Class A): myFloat = 0.5 Instance3 (Class A): myFloat = 0.65 Instance5 (Class A): myFloat = 0.55 Since objects of Class B do not have myFloat, and would not be included in the myFloat index. Instead, I get: Instance1 (Class A): myFloat = 0.5 Instance2 (Class B) Instance3 (Class A): myFloat = 0.65 Instance4 (Class B) Instance5 (Class A): myFloat = 0.55 Instance6 (Class B) In other words, I get all objects back, whether they have a myFloat attribute or not. Interestingly, if I change the query to: Catalog(myFloat=0.5, myFloat_usage='range:min') I get the expected results. Using 0.1, 0.2, 0.3, or 0.4 does not work; 0.5 seems to be the magic number, which I find curious given that 0.5 is the minimum value present in any of the instances of Class A. Can anyone shed some light on what's going on, here? How do I ask the Catalog to return all instances who have a value, any value, for myFloat, but none others? Thanks in advance, --Jeff --- Jeff K. Hoffman 704.849.0731 x108 Chief Technology Officer mailto:jeff.hoffman@goingv.com Going Virtual, L.L.C. http://www.goingv.com/