Query vectors with Go SDK V2 - Object Storage Service

Use the Go SDK V2 to call QueryVectors and run a similarity search against a vector index.

Permissions

By default, an Alibaba Cloud account has full permissions. Resource Access Management (RAM) users and RAM roles have no permissions by default — grant access using a RAM policy or a bucket policy.

API	Action	Description
QueryVectors	`oss:QueryVectors`	Queries vector data.

Method definition

func (c *VectorsClient) QueryVectors(ctx context.Context, request *QueryVectorsRequest, optFns ...func(*oss.Options)) (*QueryVectorsResult, error)

Request parameters

Parameter	Type	Required	Description
`ctx`	`context.Context`	Yes	The request context.
`request`	`*QueryVectorsRequest`	Yes	The query parameters, including the query vector, filter condition, and the number of results to return. See QueryVectorsRequest.
`optFns`	`...func(*Options)`	No	Interface-level configuration options. See Options.

Return values

Parameter	Type	Description
`result`	`*QueryVectorsResult`	The query result. Valid only when `err` is nil. See QueryVectorsResult.
`err`	`error`	The error. nil if the operation succeeds.

Sample code

The example below submits a similarity search with a metadata filter, returning the top 10 matches with their metadata and distances.

package main

import (
	"context"
	"flag"
	"log"

	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss/credentials"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss/vectors"
)

var (
	region     string
	bucketName string
	accountId  string
	indexName  string
)

func init() {
	flag.StringVar(&region, "region", "", "The region in which the vector bucket is located.")
	flag.StringVar(&bucketName, "bucket", "", "The name of the vector bucket.")
	flag.StringVar(&accountId, "account-id", "", "The ID of the vector account.")
	flag.StringVar(&indexName, "index", "", "The name of the vector index.")
}

func main() {
	flag.Parse()
	if len(bucketName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, bucket name required")
	}

	if len(region) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, region required")
	}

	if len(accountId) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, accountId required")
	}

	if len(indexName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, index required")
	}

	// Load credentials from environment variables
	cfg := oss.LoadDefaultConfig().
		WithCredentialsProvider(credentials.NewEnvironmentVariableCredentialsProvider()).
		WithRegion(region).WithAccountId(accountId)

	client := vectors.NewVectorsClient(cfg)

	request := &vectors.QueryVectorsRequest{
		Bucket:    oss.Ptr(bucketName),
		IndexName: oss.Ptr(indexName),
		// Filter using $and + $in: match vectors where "type" is "comedy" or "documentary"
		Filter: map[string]any{
			"$and": []map[string]any{
				{
					"type": map[string]any{
						"$in": []string{"comedy", "documentary"},
					},
				},
			},
		},
		QueryVector: map[string]any{
			"float32": []float32{float32(32)},
		},
		ReturnMetadata: oss.Ptr(true),
		ReturnDistance: oss.Ptr(true),
		TopK:           oss.Ptr(10),
	}

	result, err := client.QueryVectors(context.TODO(), request)
	if err != nil {
		log.Fatalf("failed to query vectors %v", err)
	}
	log.Printf("query vectors result:%#v\n", result)
}

References

For the complete sample, see query_vectors.go.