20. The system as recited in claim 18 , wherein a query expression includes: one or more attributes of a searchable data service object in the particular searchable index; and one or more operators to be applied to the one or more attributes in the query expression to locate a set of searchable data service objects that satisfy the query expression in the particular searchable index.
20. The system as recited in claim 18 , wherein a query expression includes: one or more attributes of a searchable data service object in the particular searchable index; and one or more operators to be applied to the one or more attributes in the query expression to locate a set of searchable data service objects that satisfy the query expression in the particular searchable index. 23. The system as recited in claim 20 , wherein the operators include one or more string comparison operators.