Attempting to add a database index on a property results
in an error indicating that the index limit has been reached.
Symptoms
When you attempt to add a database index (also known as
a single index) to a property that resides in an object store with
Microsoft SQL Server configured as the database engine, an error occurs
indicating that the index limit has been reached.
Causes
Microsoft SQL Server limits the total number of indexes
that can be added to class properties, including subclass properties,
per object store. The total number of indexes combined cannot exceed
the database limit. The Microsoft SQL Server limit depends on the
SQL Server version. See the Microsoft SQL Server documentation (Maximum
Capacity Specification, nonclustered indexes per table) for more information
on the limit for a specific version.
Resolving the problem
Try to reduce other indexes that might not be needed, such
as indexes that are not necessary in a query plan for a search.