ATG Search queries 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. Constraints are included in a query through the expression tag and its subtags. 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.
Constraints can also be configured using metadata or query rules; see the ATG Search Administration Guide for information.
