Multiple analyzers and query fields in Elasticsearch for auto-completion

movie-titles.rb

require 'tire'

# Tire.configure { logger STDERR, level: 'debug' }

Tire.index('movie-titles') do
  delete
  create \
    settings: {
      index: {
        analysis: {
          tokenizer: {
            title_tokenizer: {
              type: 'whitespace'
            },
          },
          filter: {
            title_ngram_filter: {
              type: 'edgeNGram',
              min_gram: 1,
              max_gram: 16,
              side: 'front'
            }
          },
          analyzer: {
            title_default_analyzer: {
              type:      'custom',
              tokenizer: 'title_tokenizer',
              filter:    ['lowercase', 'asciifolding']
            },
            title_snowball_analyzer: {
              type:      'custom',
              tokenizer: 'title_tokenizer',
              filter:    ['lowercase', 'asciifolding', 'snowball']
            },
            title_shingle_analyzer: {
              type:      'custom',
              tokenizer: 'title_tokenizer',
              filter:    ['shingle', 'lowercase', 'asciifolding']
            },
            title_ngram_analyzer: {
              type:      'custom',
              tokenizer: 'title_tokenizer',
              filter:    ['lowercase', 'asciifolding', 'title_ngram_filter']
            },
            title_search_analyzer: {
              type:      'custom',
              tokenizer: 'title_tokenizer',
              filter:    ['lowercase', 'asciifolding']
            }
          }
        }
      },
    },
    mappings: {
      document: {
        properties: {
          title: {
            type: 'multi_field',
            fields: {
              title:    { type: 'string', analyzer: 'title_default_analyzer' },
              stemmed:  { type: 'string', analyzer: 'title_snowball_analyzer' },
              shingles: { type: 'string', analyzer: 'title_shingle_analyzer' },
              ngrams:   { type: 'string', index_analyzer: 'title_ngram_analyzer', search_analyzer: 'title_search_analyzer' }
            }
          }
        }
      }
    }

  store id: 1, title: "The Lord of the Rings"
  store id: 2, title: "Lord of the Flies"
  store id: 3, title: "The Ring"
  store id: 4, title: "Lords of Dogtown"
  store id: 5, title: "The Postman Always Rings Twice"

  refresh
end

queries = [
  'lord of the rin',
  'lord of the r',
  'lord of r',
  'lord ring',
  'lord rin',
  'lo ri',
  'lord',
  'lo',
  'rings',
  'ring',
  'rin',
  'ri',
  'r'
]

queries.each do |q|
  puts '='*80,
       "QUERY: '#{q}'",
       '='*80


  s = Tire.search('movie-titles') do
    query do
      match ['title^10', 'title.snowball^2', 'title.shingles^2', 'title.ngrams'], q, operator: 'and'
    end
    explain true
  end

  s.results.each do |result|
    puts "#{result.title.ljust(30)} (Score: #{result._score})",
         # result._explanation,
         '-'*80
  end

  puts
end

output.txt

================================================================================
QUERY: 'lord of the rin'
================================================================================
The Lord of the Rings          (Score: 0.008028548)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'lord of the r'
================================================================================
The Lord of the Rings          (Score: 0.008028548)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'lord of r'
================================================================================
The Lord of the Rings          (Score: 0.005668437)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'lord ring'
================================================================================
The Lord of the Rings          (Score: 0.0039382037)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'lord rin'
================================================================================
The Lord of the Rings          (Score: 0.0039382037)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'lo ri'
================================================================================
The Lord of the Rings          (Score: 0.002912885)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'lord'
================================================================================
Lord of the Flies              (Score: 0.15342641)
--------------------------------------------------------------------------------
The Lord of the Rings          (Score: 0.13424811)
--------------------------------------------------------------------------------
Lords of Dogtown               (Score: 0.0023539662)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'lo'
================================================================================
Lords of Dogtown               (Score: 0.0023539662)
--------------------------------------------------------------------------------
Lord of the Flies              (Score: 0.0023539662)
--------------------------------------------------------------------------------
The Lord of the Rings          (Score: 0.0020597205)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'rings'
================================================================================
The Postman Always Rings Twice (Score: 0.13424811)
--------------------------------------------------------------------------------
The Lord of the Rings          (Score: 0.13424811)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'ring'
================================================================================
The Ring                       (Score: 0.19178301)
--------------------------------------------------------------------------------
The Lord of the Rings          (Score: 0.0020597205)
--------------------------------------------------------------------------------
The Postman Always Rings Twice (Score: 0.0017654747)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'rin'
================================================================================
The Ring                       (Score: 0.0035309494)
--------------------------------------------------------------------------------
The Lord of the Rings          (Score: 0.0020597205)
--------------------------------------------------------------------------------
The Postman Always Rings Twice (Score: 0.0017654747)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'ri'
================================================================================
The Ring                       (Score: 0.0035309494)
--------------------------------------------------------------------------------
The Lord of the Rings          (Score: 0.0020597205)
--------------------------------------------------------------------------------
The Postman Always Rings Twice (Score: 0.0017654747)
--------------------------------------------------------------------------------

================================================================================
QUERY: 'r'
================================================================================
The Ring                       (Score: 0.0035309494)
--------------------------------------------------------------------------------
The Lord of the Rings          (Score: 0.0020597205)
--------------------------------------------------------------------------------
The Postman Always Rings Twice (Score: 0.0017654747)
--------------------------------------------------------------------------------


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