Thanks for the suggestion. The full-text index is apparently not being used.
It is sometimes not obvious for the query optimizer how to rewrite a query to take full advantage of an index. You could try to start with a simple version of your query, see if the optimizer is used, and enhance it step by step..
1. //*:lastName[text() contains text 'Meric']
2. declare namespace core="http://atira.dk/schemas/pure4/model/core/current"; //core:lastName[text() contains text 'Meric']
3. ...
Does the results returned by core:lastName contain other descendant elements [1]? Christian