載入與釋放

載入資料集是在資料集中進行相似性檢索和查詢的先決條件。本頁重點介紹載入和釋放集合的程序。

載入資料集

當你載入一個資料集時，Milvus 將索引檔案和所有欄位的原始資料載入記憶體，以便快速回應搜尋和查詢。在集合載入後插入的實體會被自動索引和載入。

以下程式碼片段示範如何載入集合。

from pymilvus import MilvusClient

client = MilvusClient(
    uri="http://localhost:19530",
    token="root:Milvus"
)

# 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>"
# }

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 = "http://localhost:19530";
String TOKEN = "root:Milvus";

// 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

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

const address = "http://localhost:19530";
const token = "root:Milvus";
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
// 

import (
    "context"
    "fmt"
    "log"

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

defer cli.Close(ctx)

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

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

export CLUSTER_ENDPOINT="http://localhost:19530"
export TOKEN="root:Milvus"

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": ""
#     }
# }

載入特定欄位

Milvus 可以只載入搜尋和查詢所涉及的欄位，減少記憶體使用量並改善搜尋效能。

以下程式碼片段假設您建立了一個名為customized_setup_2 的集合，且集合中有兩個名為my_id和my_vector的欄位。

client.load_collection(
    collection_name="customized_setup_1",
    # 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="customized_setup_1"
)

print(res)

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

// 6. Load the collection
LoadCollectionReq loadCollectionReq = LoadCollectionReq.builder()
        .collectionName("customized_setup_1")
        .loadFields(Arrays.asList("my_id", "my_vector"))
        .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);

await client.load_collection({
  collection_name: "customized_setup_1",
  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: "customized_setup_1",
})

console.log(loadState);

import (
    "context"
    "fmt"
    "log"

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

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

loadTask, err := cli.LoadCollection(ctx, client.NewLoadCollectionOption("customized_setup_1").
    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
}

# REST 缺失

如果您選擇載入特定欄位，值得注意的是，只有包含在load_fields 中的欄位才能在搜尋和查詢中作為篩選器和輸出欄位使用。您應該始終在load_fields 中包含主要欄位和至少一個向量欄位的名稱。

您也可以使用skip_load_dynamic_field 來決定是否載入動態欄位。動態欄位是一個保留的 JSON 欄位，名為$meta，並將所有非模式定義的欄位及其值儲存在鍵值對中。載入動態欄位時，欄位中的所有鍵都會載入，並可用於篩選和輸出。如果動態欄位中的所有鍵都不參與元資料篩選和輸出，請將skip_load_dynamic_field 設為True 。

若要在集合載入後載入更多欄位，需要先釋放集合，以避免因索引變更而提示可能的錯誤。

釋放集合

搜尋和查詢是記憶體密集的作業。為了節省成本，建議您釋放目前不使用的集合。

以下程式碼片段示範如何釋放集合。

# 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>"
# }

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

// 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
// 

import (
    "context"

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

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

export CLUSTER_ENDPOINT="http://localhost:19530"
export TOKEN="root:Milvus"

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": ""
#     }
# }