Phrase and Proximity Search with ArangoSearch

Search for phrases and nearby words in full-text

With phrase search, you can query for tokens in a certain order. This allows you to match partial or full sentences. You can also specify how many arbitrary tokens may occur between defined tokens for word proximity searches.

Dataset

IMDB movie dataset

View definition

search-alias View

db.imdb_vertices.ensureIndex({ name: "inv-text", type: "inverted", fields: [ { name: "description", analyzer: "text_en" } ] });
db._createView("imdb", "search-alias", { indexes: [ { collection: "imdb_vertices", index: "inv-text" } ] });

arangosearch View

{
  "links": {
    "imdb_vertices": {
      "fields": {
        "description": {
          "analyzers": [
            "text_en"
          ]
        }
      }
    }
  }
}

Phrase Search

AQL queries

Search for movies that have the (normalized and stemmed) tokens biggest and blockbust in their description, in this order:

FOR doc IN imdb
  SEARCH PHRASE(doc.description, "BIGGEST Blockbuster", "text_en")
  RETURN {
    title: doc.title,
    description: doc.description
  }

The search phrase can be handed in via a bind parameter, but it can also be constructed dynamically using a subquery for instance:

LET p = (
  FOR word IN ["tale", "of", "a", "woman"]
    SORT RAND()
    LIMIT 2
    RETURN word
)
FOR doc IN imdb
  SEARCH ANALYZER(PHRASE(doc.description, p), "text_en")
  RETURN {
    title: doc.title,
    description: doc.description
  }

You will get different results if you re-run this query multiple times.

Proximity Search

The PHRASE() functions lets you specify tokens and the number of wildcard tokens in an alternating order. You can use this to search for two words with one arbitrary word in between the two words, for instance.

AQL queries

Match movies that contain the phrase epic <something> film in their description, where <something> can be exactly one arbitrary token:

FOR doc IN imdb
  SEARCH PHRASE(doc.description, "epic", 1, "film", "text_en")
  RETURN {
    title: doc.title,
    description: doc.description
  }

Analyzer pre-processing is applied automatically to epic and film based on the Analyzer context or an optional last argument in the call to PHRASE().

The search phrase can also be dynamic. The following query looks up a particular movie with the title Family Business, tokenizes the title and then performs a proximity search for movies with the phrase family <something> business or family <something> <something> business in their description:

LET title = DOCUMENT("imdb_vertices/39967").title // Family Business
FOR doc IN imdb
  SEARCH
    PHRASE(doc.description, INTERLEAVE(TOKENS(title, "text_en"), [1]), "text_en") OR
    PHRASE(doc.description, INTERLEAVE(TOKENS(title, "text_en"), [2]), "text_en")
  RETURN {
    title: doc.title,
    description: doc.description
  }

Combining Phrase Search with other Techniques

Phrase search is not limited to finding full and exact tokens in a particular order. It also lets you search for prefixes, strings with wildcards, etc. in the specified order. See the object tokens description of the PHRASE() function for a full list of options.

AQL queries

Match movies where the title has a token that starts with Härr (normalized to harr), followed by six arbitrary tokens and then a token that contains eni:

FOR doc IN imdb
  SEARCH PHRASE(doc.title, {STARTS_WITH: TOKENS("Härr", "text_en")[0]}, 6, {WILDCARD: "%eni%"}, "text_en")
  RETURN doc.title

The search terms used in object tokens need to be pre-processed manually as shown above with STARTS_WITH.