Enable the metadata management feature and select a retrieval mode - Object Storage Service

Call the OpenMetaQuery operation to enable the metadata management feature for a bucket and select a retrieval mode. After you enable this feature, Object Storage Service (OSS) creates a metadata index library for the bucket. OSS then builds metadata indexes for all objects in the bucket. After the index library is created, OSS performs Near Real-Time incremental scans to track and build indexes for new objects.

Notes

By default, an Alibaba Cloud account has the permission to enable the metadata management feature. If you want to use a Resource Access Management (RAM) user to enable this feature, make sure that the RAM user is granted the oss:OpenMetaQuery permission. For more information, see Grant custom permissions to a RAM user.
For more information about data indexing, see Data indexing.

Request syntax

POST /?metaQuery&comp=add&mode=basic HTTP/1.1
Host: BucketName.oss-cn-hangzhou.aliyuncs.com
Date: GMT Date
Authorization: SignatureValue

Request headers

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

Request elements

Name

Type

Required

Example

Description

mode

String

Yes

basic

The retrieval mode. Valid values:

basic (default): Scalar search
semantic: Semantic search

role

String

my-oss-role

The name of the RAM role used to access OSS. You can grant permissions to the role in the console to ensure secure access.

Response headers

All headers in the response to a DescribeRegions request are common response headers. For more information, see Common response headers.

Examples

Request example

POST /?metaQuery&comp=add&mode=basic HTTP/1.1
Host: oss-example.oss-cn-hangzhou.aliyuncs.com
Date: Thu, 17 Apr 2025 13:08:38 GMT
Authorization: OSS4-HMAC-SHA256 Credential=LTAI********************/20250417/cn-hangzhou/oss/aliyun_v4_request,Signature=a7c3554c729d71929e0b84489addee6b2e8d5cb48595adfc51868c299c0c218e

Response example

HTTP/1.1 200 OK
x-oss-request-id: 5C1B138A109F4E405B2D****
Date: Mon, 26 Jul 2021 13:08:38 GMT
Content-Length: 0
Connection: keep-alive
Server: AliyunOSS
x-oss-request-id: 5C06A3B67B8B5A3DA422299D
x-oss-server-time: 544

SDK

You can call this operation using the following SDKs:

ossutil command-line interface

For information about the ossutil command that corresponds to the OpenMetaQuery operation, see open-meta-query.