DITA defines the notion of layered hierarchy of element types, where every DITA-defined element is either a base type or a "specialized" type derived from some base type. The type hierarchy of each element is specified by a @class attribute that lists the ancestry and leaf type of the element.
For example, the element type "concept" is a specialization of the base type "topic" and so has a @class value of "- topic/topic concept/concept ". Each blank-delimited term is a module name/element name pair.
Processing in DITA is "specialization aware" if selection of elements is in terms of a @class token rather than concrete element type. For example, you might apply processing to topics of any type by matching on "*[contains(@class, ' topic/topic ')]", which will match all DITA topics, regardless of their specialized type.
The challenge this presents in a database context is optimizing finding of things based on these @class values. For large repositories an XQuery like "//*[contains(@class, ' topic/topic ')]" is going to be quite slow as it requires a string comparison of every @class value. Even if there is an attribute value index it will still be slow.
The obvious solution would be to index by @class token, e.g., an index where keys are "topic/topic", "topic/p", etc.
Is there a way to construct such an index in BaseX? Is there a better to address type of string-match-based lookup?
Thanks,
Eliot
————— Eliot Kimber, Owner Contrext, LLC http://contrext.com