searchIterator()

This method returns a search iterator to iterate search results.

public SearchIterator searchIterator(SearchIteratorReq request)

Request Syntax

searchIterator(SearchIteratorReq.builder()
        .collectionName(String collectionName)
        .databaseName(String databaseName)
        .outputFields(List<String> outputFields)
        .expr(String expr)
        .batchSize(long size)
        .vectorFieldName(String vectorFieldName)
        .vectors(List<BaseVector> vectors)
        .params(String params)
        .topK(int topk)
        .metricType(IndexParam.MetricType metricType)
        .consistencyLevel(ConsistencyLevel consistencyLevel)
        .roundDecimal(int decimal)
        .ignoreGrowing(boolean ignoreGrwing)
        .groupByFieldName(String fieldName)
        .build());

BUILDER METHODS:

• collectionName(String collectionName)

  The name of an existing collection.

• databaseName(String databaseName)

The database to which the collection belongs. You can ignore it if the database is the default.

• outputFields(List<String> outputFields)

  A list of field names to include in each entity in return.

  The value defaults to None. If left unspecified, all fields in the collection are selected as the output fields.

• expr(String expr)

  A scalar filtering condition to filter matching entities.

  You can set this parameter to an empty string to skip scalar filtering. To build a scalar filtering condition, refer to Boolean Expression Rules.

• batchSize(long size)

A value to define the number of entities returned per batch.

• vectorFieldName(String vectorFieldName)

The target vector field name to do ANN search.

• vectors(List<BaseVector> vectors)

Set the target vectors to do ANN search.

BaseVector is a base class for abstract vector classes. The following classes are derived from BaseVector. Choose the correct class as input according to DataType of the vector field.

Class Name	Constructors	Description
FloatVec	FloatVec(List\ data)FloatVec(float[] data)	For DataType.FloatVector type field.
BinaryVec	BinaryVec(ByteBuffer data)BinaryVec(byte[] data)	For DataType.BinaryVector type field.
Float16Vec	Float16Vec(ByteBuffer data)Float16Vec(byte[] data)Float16Vec(List\ data)	For DataType.Float16Vector type field.
BFloat16Vec	BFloat16Vec(ByteBuffer data)BFloat16Vec(byte[] data)BFloat16Vec(List\ data)	For DataType.BFloat16Vector type field.
SparseFloatVec	SparseFloatVec(SortedMap\ data)	For DataType.SparseFloatVector type field.

• params(String params)

A JSON format string for extra parameters.

• topK(int topk)

The topk value.

• consistencyLevel(ConsistencyLevel consistencyLevel)

  The consistency level of the target collection.

  The value defaults to the one specified when you create the current collection, with options of Strong (0), Bounded (1), Session (2), and Eventually (3).

  what is the consistency level?

  Consistency in a distributed database specifically refers to the property that ensures every node or replica has the same view of data when writing or reading data at a given time.

  Milvus supports four consistency levels: Strong, Bounded Staleness, Session, and Eventually. The default consistency level in Milvus is Bounded Staleness.

  You can easily tune the consistency level when conducting a vector similarity search or query to make it best suit your application.

• roundDecimal(int decimal)

How many digits are reserved after the decimal point.

• ignoreGrowing(boolean ignoreGrwing)

Ignore growing segments or not.

• groupByFieldName(String fieldName)

Sets the field name to do grouping for results.

RETURN TYPE:

SearchIterator

RETURNS:

A SearchIterator object to iterate search results.

METHODS:

• List<QueryResultsWrapper.RowRecord> next()

Return a batch of results.

• close()

Release the cache results.

EXCEPTIONS:

• MilvusClientExceptions

  This exception will be raised when any error occurs during this operation.

Example

List<Float> vector = generateFloatVector();
SearchIterator searchIterator = client.searchIterator(SearchIteratorReq.builder()
        .collectionName(COLLECTION_NAME)
        .outputFields(Lists.newArrayList("vector"))
        .batchSize(50L)
        .vectorFieldName("vector")
        .vectors(Collections.singletonList(new FloatVec(vector)))
        .expr("id > 100")
        .params("{\"range_filter\": 15.0, \"radius\": 20.0}")
        .topK(300)
        .metricType(IndexParam.MetricType.L2)
        .consistencyLevel(ConsistencyLevel.BOUNDED)
        .build());

while (true) {
    List<QueryResultsWrapper.RowRecord> res = searchIterator.next();
    if (res.isEmpty()) {
        System.out.println("Search iteration finished, close");
        searchIterator.close();
        break;
    }

    for (QueryResultsWrapper.RowRecord record : res) {
        System.out.println(record);
    }
}