One of the major performance pains when building the model is the excessive cost associated with creating TypeUsage instances. This is due in part to the way they work and how the are supposed to be read-only but in reality mutate through re-construction of instances and re-setting of properties.
An “improvement” was implemented where the properties’ setter would only change the value if it was different from the one it already had (the cost of getting the value versus the change of the property value ratio was positive for us in most cases), but the inherent problem is still there.
For a customer scenario where the cost of TypeUsage is known to affect performance, see [workitem 1339](https://entityframework.codeplex.com/workitem/1339).
An “improvement” was implemented where the properties’ setter would only change the value if it was different from the one it already had (the cost of getting the value versus the change of the property value ratio was positive for us in most cases), but the inherent problem is still there.
For a customer scenario where the cost of TypeUsage is known to affect performance, see [workitem 1339](https://entityframework.codeplex.com/workitem/1339).