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FieldTermMatchCount

Last Updated: Sep 09, 2021

Overview

Calculates the number of terms that match a search query in a field. For example, the terms in the title field after analysis are field, match, ratio, user, and guide, and the terms in a search query after analysis are OpenSearch, user, and guide. In this case, the number of terms that match the search query in the title field is 2.

Functions

Function

Description

FieldTermMatchCount create(OpsScorerInitParams params, CString indexName, CString fieldName)

Creates a FieldTermMatchCount object. This function is a factory function.

void setGroupScoreMergeOp(CString opName)

Sets an aggregation method for the FieldTermMatchCount scores of multiple query groups. Supported aggregation methods are sum and max. The default aggregation method is sum.

double evaluate(OpsScoreParams params)

Calculates the number of terms that match a search query in a field.

Function details

FieldTermMatchCount create(OpsScorerInitParams params, CString indexName, CString fieldName)

Creates a FieldTermMatchCount object based on a specified index and a specified field. This function is a factory function. Parameters: params: the parameters that are used for initialization. For more information, see OpsScorerInitParams. indexName: the name of an index. The name must be a constant. The analyzer can be the general analyzer for Chinese, a custom analyzer, the single character analyzer for Chinese, an analyzer for English, or the analyzer for fuzzy searches. fieldName: the name of a field in the specified index. The name must be a constant. The field must be of the TEXT or SHORT_TEXT type.

void setGroupScoreMergeOp(CString opName)

Sets an aggregation method for the FieldTermMatchCount scores of multiple query groups. This function must be invoked in the init function. Parameter: opName: the name of an operator. Supported operators are sum and max. The sum operator calculates a sum of multiple scores. The max operator returns the maximum value among multiple scores. The default value is sum.

double evaluate(OpsScoreParams params)

Calculates the number of terms that match a search query in a field. Parameter: params: the parameters that are used for score calculation. For more information, see OpsScoreParams. Return value: the number of terms that match a search query in a field. Sample code:

package users.scorer;
import com.aliyun.opensearch.cava.framework.OpsScoreParams;
import com.aliyun.opensearch.cava.framework.OpsScorerInitParams;
import com.aliyun.opensearch.cava.features.similarity.fieldmatch.FieldTermMatchCount;

class BasicSimilarityScorer {
    FieldTermMatchCount _fieldTermMatchCount;
    boolean init(OpsScorerInitParams params) {
        _fieldTermMatchCount = FieldTermMatchCount.create(params, "title_index", "title");
        _fieldTermMatchCount.setGroupScoreMergeOp("max");
        return true;
    }

    double score(OpsScoreParams params) {
        return _fieldTermMatchCount.evaluate(params);
    }
}