Stop

The stop filter removes specified stop words from tokenized text, helping to eliminate common, less meaningful words. You can configure the list of stop words using the stop_words parameter.

Configuration

The stop filter is a custom filter in Milvus. To use it, specify "type": "stop" in the filter configuration, along with a stop_words parameter that provides a list of stop words.

analyzer_params = {
    "tokenizer": "standard",
    "filter":[{
        "type": "stop", # Specifies the filter type as stop
        "stop_words": ["of", "to", "_english_"], # Defines custom stop words and includes the English stop word list
    }],
}

Map<String, Object> analyzerParams = new HashMap<>();
analyzerParams.put("tokenizer", "standard");
analyzerParams.put("filter",
        Collections.singletonList(
                new HashMap<String, Object>() {{
                    put("type", "stop");
                    put("stop_words", Arrays.asList("of", "to", "_english_"));
                }}
        )
);

const analyzer_params = {
    "tokenizer": "standard",
    "filter":[{
        "type": "stop", # Specifies the filter type as stop
        "stop_words": ["of", "to", "_english_"], # Defines custom stop words and includes the English stop word list
    }],
};

analyzerParams = map[string]any{"tokenizer": "standard",
    "filter": []any{map[string]any{
        "type":       "stop",
        "stop_words": []string{"of", "to", "_english_"},
    }}}

# restful
analyzerParams='{
  "tokenizer": "standard",
  "filter": [
    {
      "type": "stop",
      "stop_words": [
        "of",
        "to",
        "_english_"
      ]
    }
  ]
}'

The stop filter accepts the following configurable parameters.

Parameter

Description

stop_words

A list of words to be removed from tokenization. By default, the filter uses the built‑in _english_ dictionary. You can override or extend it in three ways: Built‑in dictionaries – supply one of these language aliases to use a predefined dictionary: "_english_", "_danish_", "_dutch_", "_finnish_", "_french_", "_german_", "_hungarian_", "_italian_", "_norwegian_", "_portuguese_", "_russian_", "_spanish_", "_swedish_" Custom list – pass an array of your own terms, e.g. ["foo", "bar", "baz"]. Mixed list – combine aliases and custom terms, e.g. ["of", "to", "_english_"]. For details on the exact content of each predefined dictionary, refer to stop_words.

The stop filter operates on the terms generated by the tokenizer, so it must be used in combination with a tokenizer. For a list of tokenizers available in Milvus, refer to Standard Tokenizer and its sibling pages.

After defining analyzer_params, you can apply them to a VARCHAR field when defining a collection schema. This allows Milvus to process the text in that field using the specified analyzer for efficient tokenization and filtering. For details, refer to Example use.

Examples

Before applying the analyzer configuration to your collection schema, verify its behavior using the run_analyzer method.

Analyzer configuration

analyzer_params = {
    "tokenizer": "standard",
    "filter":[{
        "type": "stop", # Specifies the filter type as stop
        "stop_words": ["of", "to", "_english_"], # Defines custom stop words and includes the English stop word list
    }],
}

Map<String, Object> analyzerParams = new HashMap<>();
analyzerParams.put("tokenizer", "standard");
analyzerParams.put("filter",
        Collections.singletonList(
                new HashMap<String, Object>() {{
                    put("type", "stop");
                    put("stop_words", Arrays.asList("of", "to", "_english_"));
                }}
        )
);

// javascript

analyzerParams = map[string]any{"tokenizer": "standard",
    "filter": []any{map[string]any{
        "type":       "stop",
        "stop_words": []string{"of", "to", "_english_"},
    }}}

# restful

Verification using run_analyzer

# Sample text to analyze
sample_text = "The stop filter allows control over common stop words for text processing."

# Run the standard analyzer with the defined configuration
result = MilvusClient.run_analyzer(sample_text, analyzer_params)
print(result)

// java

// javascript

// go

# restful

Expected output

['The', 'stop', 'filter', 'allows', 'control', 'over', 'common', 'stop', 'words', 'text', 'processing']