Object Storage Service:QueryVectors

Permissions

By default, an Alibaba Cloud account has full permissions, whereas a RAM user or RAM role has none. The Alibaba Cloud account owner or an administrator must grant permissions by using a RAM policy or a bucket policy.

Request syntax

The recall rate for QueryVectors calls may be low for up to 30 seconds after a vector index is created. Data written by using the PutVectors operation becomes available for querying in approximately 2 to 3 seconds.

POST /?queryVectors HTTP/1.1
Host: examplebucket-123***456.cn-hangzhou-internal.oss-vectors.aliyuncs.com
Date: GMT Date
Authorization: SignatureValue
Content-type: application/json

{
   "filter": {
       "$and": [{
           "type": {
               "$in": ["comedy", "documentary"]
           }
       }, {
           "year": {
               "$eq": "2020"
           }
       }]
    },
   "indexName": "string",
   "queryVector": {
       "float32":[float]
    },
   "returnDistance": boolean,
   "returnMetadata": boolean,
   "topK": int
}

Request headers

This operation uses only common request headers. For more information, see Common HTTP headers.

Request parameters

// Simple equality (uses $eq by default when the operator is omitted)
{"category": "finance"}

// Explicit equality / inequality
{"category": {"$eq": "finance"}}
{"category": {"$ne": "archived"}}

// Numeric comparison
{"created_year": {"$gt": 2023}}
{"created_year": {"$gte": 2024}}
{"created_year": {"$lt": 2026}}
{"created_year": {"$lte": 2025}}

// Array matching
{"language": {"$in": ["zh", "en"]}}
{"language": {"$nin": ["ja", "ko"]}}

// Existence check
{"author": {"$exists": true}}

// Logical combination
{"$and": [{"category": {"$eq": "finance"}}, {"created_year": {"$gte": 2024}}]}
{"$or": [{"category": {"$eq": "finance"}}, {"category": {"$eq": "tech"}}]}
{"$nor": [{"category": {"$eq": "finance"}}, {"category": {"$eq": "tech"}}]}

// Multiple conditions on the same field (range)
{"score": {"$gte": 0.6, "$lte": 0.95}}

Response headers

This operation uses only common response headers. For more information, see Common HTTP headers.

Response elements

Examples

POST /?queryVectors HTTP/1.1
Host: examplebucket-123***456.cn-hangzhou-internal.oss-vectors.aliyuncs.com
Date: Thu, 17 Apr 2025 01:33:47 GMT
Authorization: OSS4-HMAC-SHA256 Credential=LTAI********************/20250417/cn-hangzhou/oss/aliyun_v4_request,Signature=a7c3554c729d71929e0b84489addee6b2e8d5cb48595adfc51868c299c0c218
Content-type: application/json

{
   "filter": {
       "$and": [{
           "category": {
               "$in": ["technology", "science"]
           }
       }, {
           "year": {
               "$eq": "2020"
           }
       }]
    },
   "indexName": "vectorindex1",
   "queryVector": {
       "float32": [0.15, 0.25, 0.35, 0.45, 0.55]
    },
   "returnDistance": true,
   "returnMetadata": true,
   "topK": 5
}

Sample response

HTTP/1.1 200 OK
x-oss-request-id: 534B371674E88A4D8906****
Date: Thu, 17 Apr 2025 01:33:47 GMT
Connection: keep-alive
Server: AliyunOSS
Content-type: application/json

{
   "vectors": [ 
      { 
         "distance": 0.12,
         "key": "doc-001",
         "metadata": {
             "category": ["technology", "ai"],
             "title": "Introduction to Vector Search",
             "year": "2020"
         }
      },
      { 
         "distance": 0.25,
         "key": "doc-003",
         "metadata": {
             "category": ["science"],
             "title": "Advanced Vector Operations",
             "year": "2020"
         }
      }
   ]
}

SDK

The QueryVectors operation is available in the following SDKs:

• Retrieve vectors (Python SDK V2)

• Retrieve vectors (Go SDK V2)

ossutil CLI

You can use the query-vectors command in the ossutil command-line tool to perform this operation.

Error codes