How to Define a Custom Analyzer and Run a Diacritic-Insensitive Query

Navigate to the Atlas Search page for your project.

1. If it is not already displayed, select the organization that contains your desired project from the Organizations menu in the navigation bar.

2. If it is not already displayed, select your desired project from the Projects menu in the navigation bar.

3. Click your cluster's name.

4. Click the Search tab.

Click Create Index.

Select JSON editor for the Configuration Method and click Next.

Enter the Index Name, and set the Database and Collection.

1. In the Index Name field, enter default.

   Note

   If you name your index default, you don't need to specify an index parameter when using the $search pipeline stage. Otherwise, you must specify the index name using the index parameter.

2. In the Database and Collection section, find the sample_mflix database, and select the movies collection.

Specify an index definition.

Use the JSON Editor in the Atlas user interface to create the index.

1. Replace the default definition with the following:

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{
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  "mappings": {
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    "fields": {
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      "genres": {
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        "type": "string"
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      },
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      "title": {
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        "analyzer": "diacriticFolder",
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        "type": "string"
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      }
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    }
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  },
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  "analyzers": [{
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    "charFilters": [],
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    "name": "diacriticFolder",
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    "tokenizer": {
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      "type": "keyword"
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    },
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    "tokenFilters": [{
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      "type": "icuFolding"
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    }]
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  }]
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}

This index definition for the genres and title fields specifies a custom analyzer, diacriticFolder, using the following:

• keyword tokenizer that tokenizes the entire input as a single token.

• icuFolding token filter that applies character foldings such as accent removal and case folding.

The index definition specifies a string type for the genres and title fields. It also applies the custom analyzer named diacriticFolder on the title field.

2. Click Next.

Click Create Search Index.

Close the You're All Set! Modal Window.

A modal window appears to let you know your index is building. Click the Close button.

Wait for the index to finish building.

The index should take about one minute to build. While it is building, the Status column reads Build in Progress. When it is finished building, the Status column reads Active.