The current state of the global secondary index: 
- CREATING - The index is being created, as the result of a CreateTable or UpdateTable operation.
- UPDATING - The index is being updated, as the result of a CreateTable or UpdateTable operation.
- DELETING - The index is being deleted, as the result of a DeleteTable operation.
- ACTIVE - The index is ready for use.
Constraints:
 Declaration Syntax
 Declaration Syntax| C# | 
public string IndexStatus { get; set; }