Load 和 Release

对 Collection 执行 Load 操作是在 Collection 中进行 Search 和 Query 的前提条件。本节主要介绍如何 Load 和 Release Collection。

Load Collection

在加载 Collection 时，Zilliz Cloud 会将所有向量列的索引文件和所有标量列的数据加载到QueryNode，从而快速响应搜索和查询请求。在 Collection 加载后插入的数据会自动完成索引和加载。

您可以参考如下代码 Load Collection。

Python

from pymilvus import MilvusClient

client = MilvusClient(
    uri="YOUR_CLUSTER_ENDPOINT",
    token="YOUR_CLUSTER_TOKEN"
)

# 7. Load the collection
client.load_collection(
    collection_name="customized_setup_1"
)

res = client.get_load_state(
    collection_name="customized_setup_1"
)

print(res)

# Output
#
# {
#     "state": "<LoadState: Loaded>"
# }

Java

import io.milvus.v2.service.collection.request.LoadCollectionReq;
import io.milvus.v2.service.collection.request.GetLoadStateReq;
import io.milvus.v2.client.ConnectConfig;
import io.milvus.v2.client.MilvusClientV2;

String CLUSTER_ENDPOINT = "YOUR_CLUSTER_ENDPOINT";
String TOKEN = "YOUR_CLUSTER_TOKEN";

// 1. Connect to Milvus server
ConnectConfig connectConfig = ConnectConfig.builder()
        .uri(CLUSTER_ENDPOINT)
        .token(TOKEN)
        .build();

MilvusClientV2 client = new MilvusClientV2(connectConfig);

// 6. Load the collection
LoadCollectionReq loadCollectionReq = LoadCollectionReq.builder()
        .collectionName("customized_setup_1")
        .build();

client.loadCollection(loadCollectionReq);

// 7. Get load state of the collection
GetLoadStateReq loadStateReq = GetLoadStateReq.builder()
        .collectionName("customized_setup_1")
        .build();

Boolean res = client.getLoadState(loadStateReq);
System.out.println(res);

// Output:
// true

NodeJS

import { MilvusClient, DataType } from "@zilliz/milvus2-sdk-node";

const address = "YOUR_CLUSTER_ENDPOINT";
const token = "YOUR_CLUSTER_TOKEN";
const client = new MilvusClient({address, token});

// 7. Load the collection
res = await client.loadCollection({
    collection_name: "customized_setup_1"
})

console.log(res.error_code)

// Output
// 
// Success
// 

res = await client.getLoadState({
    collection_name: "customized_setup_1"
})

console.log(res.state)

// Output
// 
// LoadStateLoaded
// 

Go

import (
    "context"
    "fmt"
    "log"

    "github.com/milvus-io/milvus/client/v2/milvusclient"
)

loadTask, err := cli.LoadCollection(ctx, milvusclient.NewLoadCollectionOption("customized_setup_1"))
if err != nil {
    // handle error
}

// sync wait collection to be loaded
err = loadTask.Await(ctx)
if err != nil {
    // handle error
}

cURL

export CLUSTER_ENDPOINT="YOUR_CLUSTER_ENDPOINT"
export TOKEN="YOUR_CLUSTER_TOKEN"

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/collections/load" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "collectionName": "customized_setup_1"
}'

# {
#     "code": 0,
#     "data": {}
# }

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/collections/get_load_state" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "collectionName": "customized_setup_1"
}'

# {
#     "code": 0,
#     "data": {
#         "loadProgress": 100,
#         "loadState": "LoadStateLoaded",
#         "message": ""
#     }
# }

Load 部分字段

为了节约内存资源，您可以选择让 Zilliz Cloud 仅加载参与 Search 和 Query 的部分字段，提升搜索性能。

如下代码中假设名为 customized_setup_1 的 Collection 中有名为 my_id 和 my_vector 两个字段。

Python

client.load_collection(
    collection_name="custom_quick_setup",
    # highlight-next-line
    load_fields=["my_id", "my_vector"], # Load only the specified fields
    skip_load_dynamic_field=True # Skip loading the dynamic field
)

res = client.get_load_state(
    collection_name="custom_quick_setup"
)

# Output
#
# {
#     "state": "<LoadState: Loaded>"
# }

Java

// 6. Load the collection
LoadCollectionReq loadCollectionReq = LoadCollectionReq.builder()
        .collectionName("custom_quick_setup")
        .loadFields(Arrays.asList("my_id", "my_vector"))
        .build();

client.loadCollection(loadCollectionReq);

// 7. Get load state of the collection
GetLoadStateReq loadStateReq = GetLoadStateReq.builder()
        .collectionName("custom_quick_setup")
        .build();

Boolean res = client.getLoadState(loadStateReq);
System.out.println(res);

NodeJS

await client.load_collection({
  collection_name: "custom_quick_setup",
  load_fields: ["my_id", "my_vector"], // Load only the specified fields
  skip_load_dynamic_field: true //Skip loading the dynamic field
});

const loadState = client.getCollectionLoadState({
    collection_name: "custom_quick_setup",
})

console.log(loadState);

Go

import (
    "context"
    "fmt"
    "log"

    "github.com/milvus-io/milvus/client/v2/milvusclient"
)

ctx, cancel := context.WithCancel(context.Background())
defer cancel()

loadTask, err := cli.LoadCollection(ctx, milvusclient.NewLoadCollectionOption("custom_quick_setup").
    WithLoadFields("my_id", "my_vector"))
if err != nil {
    // handle error
}

// sync wait collection to be loaded
err = loadTask.Await(ctx)
if err != nil {
    // handle error
}

cURL

# REST 缺失

需要注意的是，当您选择只加载部分字段时，只有在 load_fields 中的字段可以做为过滤条件（filter）和输出字段（Output Fields）使用。请务必在 load_fields 包含主键和至少一个已创建索引的向量字段。

您还可以使用 skip_load_dynamic_field 来决定是否加载 Dynamic Field。Dynamic Field 是一个名为 $meta 的预留 JSON 字段，用于以键值对的形式存放各 Entity 中所有未在 Schema 中定义的字段及其值。在加载 Dynamic Field 时，字段中所有键都会被加载，并可用于过滤和输出。如果 Dynamic Field 中的键无须参与过滤或输出，您可以将 skip_load_dynamic_field 设置为 True。

如果在执行本操作后需要 Load 更多字段，请务必先对 Collection 执行 Release 操作，避免因索引结构发生变化而引发系统报错。

Release Collection

由于 Search 和 Query 操作会占用较多的内存资源。为了减少资源消耗，您可以对暂时不需要使用的 Collection 执行 Release 操作，将相关数据从内存中释放出来。

如下示例演示了如何 Release Collection。

Python

# 8. Release the collection
client.release_collection(
    collection_name="custom_quick_setup"
)

res = client.get_load_state(
    collection_name="custom_quick_setup"
)

print(res)

# Output
#
# {
#     "state": "<LoadState: NotLoad>"
# }

Java

import io.milvus.v2.service.collection.request.ReleaseCollectionReq;

// 8. Release the collection
ReleaseCollectionReq releaseCollectionReq = ReleaseCollectionReq.builder()
        .collectionName("custom_quick_setup")
        .build();

client.releaseCollection(releaseCollectionReq);

GetLoadStateReq loadStateReq = GetLoadStateReq.builder()
        .collectionName("custom_quick_setup")
        .build();
Boolean res = client.getLoadState(loadStateReq);
System.out.println(res);

// Output:
// false

NodeJS

// 8. Release the collection
res = await client.releaseCollection({
    collection_name: "custom_quick_setup"
})

console.log(res.error_code)

// Output
// 
// Success
// 

res = await client.getLoadState({
    collection_name: "custom_quick_setup"
})

console.log(res.state)

// Output
// 
// LoadStateNotLoad
// 

Go

import (
    "context"

    "github.com/milvus-io/milvus/client/v2/milvusclient"
)

err := cli.ReleaseCollection(ctx, milvusclient.NewReleaseCollectionOption("custom_quick_setup"))
if err != nil {
    // handle error
}

cURL

export CLUSTER_ENDPOINT="YOUR_CLUSTER_ENDPOINT"
export TOKEN="YOUR_CLUSTER_TOKEN"

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/collections/release" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "collectionName": "custom_quick_setup"
}'

# {
#     "code": 0,
#     "data": {}
# }

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/collections/get_load_state" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "collectionName": "custom_quick_setup"
}'

# {
#     "code": 0,
#     "data": {
#         "loadProgress": 0,
#         "loadState": "LoadStateNotLoaded",
#         "message": ""
#     }
# }