Create a collection - Vector Retrieval Service - Alibaba Cloud Documentation Center

This topic describes how to create a collection by using the SDK for Java.

Prerequisites

A cluster is created. For more information, see Create a cluster.
An API key is obtained. For more information, see Manage API keys.
The SDK of the latest version is installed. For more information, see Install DashVector SDK.

API definition

Java

// class DashVectorClient

// Create a collection by specifying the name and number of vector dimensions.
public Response<Void> create(String name, int dimension);

// Create a collection by using a CreateCollectionRequest object.
public Response<Void> create(CreateCollectionRequest request);

Example

Note

You need to replace YOUR_API_KEY with your API key and YOUR_CLUSTER_ENDPOINT with the endpoint of your cluster in the sample code for the code to run properly.

Java

import com.aliyun.dashvector.DashVectorClient;
import com.aliyun.dashvector.common.DashVectorException;
import com.aliyun.dashvector.models.requests.CreateCollectionRequest;
import com.aliyun.dashvector.models.responses.Response;
import com.aliyun.dashvector.proto.CollectionInfo;
import com.aliyun.dashvector.proto.FieldType;

public class Main {
    public static void main(String[] args) throws DashVectorException {
        DashVectorClient client = new DashVectorClient("YOUR_API_KEY", "YOUR_CLUSTER_ENDPOINT");

        // Create a collection by using a CreateCollectionRequest object.
      
        // Create a collection and set its name to quickstart, the number of vector dimensions to 4, 
        // vector data type to the default value of DataType.FLOAT, 
        // and distance metric to dotproduct.
        // Predefine the name, weight, and age fields, and set their data types to STRING, FLOAT, and INT, respectively.
        CreateCollectionRequest request = CreateCollectionRequest.builder()
            .name("quickstart")
            .dimension(4)
            .metric(CollectionInfo.Metric.dotproduct)
            .dataType(CollectionInfo.DataType.FLOAT)
            .fieldSchema("name", FieldType.STRING)
            .fieldSchema("weight", FieldType.FLOAT)
            .fieldSchema("age", FieldType.INT)
            .build();
      
        Response<Void> response = client.create(request);

        System.out.println(response);
        // Output example:
        // {"code":0,"message":"","requestId":"883716a3-32f8-4220-ae54-245fa9b87bf0"}
    }
}

Request parameters

You can use a CreateCollectionRequestBuilder instance to build a CreateCollectionRequest object. The following table describes the methods that can be called by the instance.

Method	Required	Default value	Description
name(String name)	Yes	-	Sets the name of the collection to be created.
dimension(int dimension)	Yes	-	Sets the number of vector dimensions.
dataType(CollectionInfo.DataType dataType)	No	DataType.FLOAT	Sets the vector data type. Valid values: `DataType.INT` `DataType.FLOAT`
fieldsSchema(Map<String, FieldType> fieldsSchem)	No	-	Sets fields. Valid data types: `FieldType.BOOL` `FieldType.STRING` `FieldType.INT` `FieldType.FLOAT`
fieldSchema(String key, FieldType value)	No	-
metric(CollectionInfo.Metric metric)	No	Metric.cosine	Sets the distance metric. Valid values: `Metric.cosine` `Metric.euclidean` `Metric.dotproduct` If the metric is `cosine`, the `datatype()` method must set the field data type to `FLOAT`.
metric(CollectionInfo.Metric metric)	No	Metric.cosine
timeout(Integer timeout)	No	-	Sets the timeout period. If you set `timeout` to null, the method works in synchronous mode and returns a response when the collection is successfully created. If you set `timeout` to -1, the method works in asynchronous mode. If you set `timeout` to a value greater than or equal to 0, the method works in synchronous mode and waits for the operation result within the specified timeout period. The method returns a timeout error if the collection fails to be created within the specified timeout period.


build()	-	-	Builds a `CreateCollectionRequest` object.

Note

For more information about the advantages of predefining fields during collection creation, see Schema-free.

Response parameters

Note

A Response<Void> object is returned, which contains the operation result, as described in the following table.

Method	Type	Description	Example
getCode()	int	The returned status code. For more information, see Status codes.	0
getMessage()	String	The returned message.	success
getRequestId()	String	The unique ID of the request.	19215409-ea66-4db9-8764-26ce2eb5bb99
isSuccess()	Boolean	Specifies whether the operation is successful.	true