Case-insensitive Search with ArangoSearch

You can normalize values for case-insensitive matching and to ignore diacritics, also in combination with other search techniques

Normalizing a Single Token

Dataset

IMDB movie dataset

Custom Analyzer

Create a norm Analyzer in arangosh to normalize case to all lowercase and to remove diacritics:

//db._useDatabase("your_database"); // Analyzer will be created in current database
var analyzers = require("@arangodb/analyzers");
analyzers.save("norm_en", "norm", { locale: "en", accent: false, case: "lower" }, ["frequency", "norm", "position"]);

View definition

search-alias View

db.imdb_vertices.ensureIndex({ name: "inv-ci", type: "inverted", fields: [ { name: "title", analyzer: "norm_en" } ] });
db._createView("imdb_alias", "search-alias", { indexes: [ { collection: "imdb_vertices", index: "inv-ci" } ] });

arangosearch View

{
  "links": {
    "imdb_vertices": {
      "fields": {
        "title": {
          "analyzers": [
            "norm_en"
          ]
        }
      }
    }
  }
}

AQL queries

Example: Full string matching

Match movie title, ignoring capitalization and using the base characters instead of accented characters (full string).

search-alias View:

FOR doc IN imdb_alias
  SEARCH doc.title == TOKENS("thé mäTRïX", "norm_en")[0]
  RETURN doc.title

arangosearch View:

FOR doc IN imdb
  SEARCH ANALYZER(doc.title == TOKENS("thé mäTRïX", "norm_en")[0], "norm_en")
  RETURN doc.title

Example: Prefix matching

Match a title prefix (case-insensitive).

search-alias View:

FOR doc IN imdb_alias
  SEARCH STARTS_WITH(doc.title, "the matr")
  RETURN doc.title

arangosearch View:

FOR doc IN imdb
  SEARCH ANALYZER(STARTS_WITH(doc.title, "the matr"), "norm_en")
  RETURN doc.title