Adding more than one text-query index

[Laura Morales]

The good news is that I've been able to get the index working, but I don't 
fully understand what I'm doing...

Taken from the documentation 
(https://jena.apache.org/documentation/query/text-query.html)

# Text index description
<#indexLucene> a text:TextIndexLucene ;
    text:directory <file:Lucene> ;
    ##text:directory "mem" ;
    text:entityMap <#entMap> ;
    .

# Mapping in the index
# URI stored in field "uri"
# rdfs:label is mapped to field "text"
<#entMap> a text:EntityMap ;
    text:entityField      "uri" ;
    text:defaultField     "text" ;
    text:map (
         [ text:field "text" ; text:predicate rdfs:label ]
         ) .



Question 1) If I want to add more indexes, do I just add more of 
"text:entityMap <#entMap>" to <#indexLucene>? Like "text:entityMap 
<#entMap-1>", "text:entityMap <#entMap-2>", etc...

Question 2) I don't understand what's going on in <#entMap>. What are 
entityField, defaultField, and how does mapping work?!