Understanding Path Range Indexes
A path range index enables you to define a range index on an XML element, XML attribute, or JSON property using an XPath expression. A path range index can give you finer control over what is indexed. For example, if your content contains elements with the same name at multiple levels, but you only want to index one of them, you can use a path range index to target just that one.
This section describes the XPath expressions you can use to define a path range index. For performance reasons, MarkLogic Server restricts you to a subset of XPath when defining a path range index.