Some ATG Search query types can include constraints, which limit the search space within the index. There are three major types of constraints: document set constraints, index item constraints, and statement-level constraints.
Document set and item constraints can be arbitrarily combined into a single Boolean expression of individual constraints. Documents that satisfy the Boolean expression are accessible to search; documents that do not satisfy the expression are inaccessible.
ATG Search uses XML to represent the query constraint expressions. Appropriate controls must be included in the interface so that end-users can make their selections, and the XML is constructed programmatically. The full BNF of this XML is shown in the Query Constraint Expressions section.
