What is the impact of attributes on performance?

[Jef_E]

Hi!

I would like to store multiple attribute items on drawing views, but I wonder.. what is the effect on the drawing performance when adding multiple attributes? The data type stored into the attribute will be string.

Performance
Conceptually, attributes are appended to persistent objects in Autodesk Inventor. In reality, the link is rather more tenuous. Autodesk Inventor is a parametric modeler; a uniform system for parts and assemblies. Objects in Inventor easily change, whether driven by parameters or as a result of a modeling operation such as the addition of a hole. So a persistent object such as a face is not necessarily as persistent or consistently identifiable as it first appears.

Autodesk Inventor has a complex search algorithm to enable it to consistently identify objects throughout their lifetime. This mechanism is employed by ReferenceKeys, a concept similar to handles in AutoCAD. This internal ReferenceKeys mechanism provides a reliable and robust link between an AttributeSet and the object to which it is appended. However, the link is potentially expensive in terms of processing time, particularly when you are working with large numbers of Attributes. There are several ways to mitigate the effects of this performance issue.

Autodesk Inventor builds a cache of object-to-AttributeSet links as these links are referenced. This cache greatly reduces access time for subsequent references. You can force Autodesk Inventor to build the entire cache, for all objects, by calling the FindObjects method with no arguments. Then perform your query. Note though that continued modeling operations will destroy the cache. 
When working with large numbers of Attributes, enclose your Attribute editing in a Transaction or ChangeProcessor. This tells Autodesk Inventor not to use its own automatic transaction and undo mechanism, greatly improving performance. 
Also consider
Attributes are often used in conjunction with ReferenceKeys. Use Referencekeys to obtain a persistent identifier for a given Autodesk Inventor object. This identifier is valid from session to session. For example, an application can establish a relationship between objects in an assembly by storing a ReferenceKey for one object in a persistent attribute on another.

I found this in the programming help, but it doesn't really make sense to me. Lets say I would store 1 attribute set with 10 items in it each with +- 100 sings in it. What would this mean?

• In performance while opening the drawing
• In performance while editing the drawing
• In performance while saving the drawing
• In performance while accessing the attribute sets