Hints: Elasticsearch hints allow to refine your query by leveraging native Elasticsearch query capabilities, like fuzzy search, geoshape search, phonems, etc.
Hints are a combination of optionnel analyser, operator and index field. With hints, you will be able to configure search behaviours like : “Give me all the documents that have similar words than “Amstredam” and returns the one with Amsterdam”, or Give me all the pictures who are 5 kms away at max from the Eiffel Tower”. Usage of hints is not for “beginner” users as it require some knowledge of Elasticsearch, especially for understanding which combinations make sense to be used.
You can find sample requests on the online documentation (https://doc.nuxeo.com/display/NXDOC/NXQL#NXQL-ElasticsearchNXQLHints) and you should also be familiar with the Elasticsearch documentation about query operators (https://www.elastic.co/guide/en/elasticsearch/reference/1.x/query-dsl-queries.html) and analysers (https://www.elastic.co/guide/en/elasticsearch/reference/1.x/analysis.html).
Analyzer: Fill with the name of an existing Elasticsearch analyzer. This analyzer can only be used if the operator can handle it. Analysers are configured on Elasticsearch server and are a combination of a tokenizers and one or more filters. More information on analysers on Elasticsearch doc(https://www.elastic.co/guide/en/elasticsearch/reference/1.x/analysis-analyzers.html). See how to configure an analyser on your Elasticsearch server via the Nuxeo Mapping (https://doc.nuxeo.com/x/WxI5AQ)
Index: Fill with one or multiple Elasticsearch index fields, comma separated. Example: "dc:title.fulltext,dc:description.fulltext”. You can configure new elastic search field by updating the elastic search mapping (https://doc.nuxeo.com/display/ADMINDOC/Elasticsearch+setup#ElasticsearchSetup-changingElasticsearchMappingChangingtheMappingoftheIndex). You typically want to do this when you want to use a specific analyser on the values of your document property. Or if you want to combine multiple sources of data into one ES field.
Operator: Fill with an operator that will override the operator defined above. Operators will affect the behaviour for determining the matching conditions of your query, adding new capabilities towards usual =, <, > etc… For instance, finding all the elements in a given geographical area. You can also use regex, match_phrase… Note that not all the es operators are available hence the drop down control.