Database

Milvus introduces a database layer above collections, providing a more efficient way to manage and organize your data while supporting multi-tenancy.

What is a database

In Milvus, a database serves as a logical unit for organizing and managing data. To enhance data security and achieve multi-tenancy, you can create multiple databases to logically isolate data for different applications or tenants. For example, you create a database to store the data of user A and another database for user B.

Create database

You can use the Milvus RESTful API or SDKs to create data programmatically.

from pymilvus import MilvusClient

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

client.create_database(
    db_name="my_database_1"
)

import io.milvus.v2.client.MilvusClientV2;
import io.milvus.v2.client.ConnectConfig;
import io.milvus.v2.service.database.request.*;

ConnectConfig config = ConnectConfig.builder()
        .uri("http://localhost:19530")
        .token("root:Milvus")
        .build();
MilvusClientV2 client = new MilvusClientV2(config);

CreateDatabaseReq createDatabaseReq = CreateDatabaseReq.builder()
        .databaseName("my_database_1")
        .build();
client.createDatabase(createDatabaseReq);

import {MilvusClient} from '@zilliz/milvus2-sdk-node';
const client = new MilvusClient({ 
    address: "http://localhost:19530",
    token: 'root:Milvus' 
});

await client.createDatabase({
    db_name: "my_database_1"
 });

cli, err := milvusclient.New(ctx, &milvusclient.ClientConfig{
    Address: "localhost:19530",
    Username: "Milvus",
    Password: "root",
})
if err != nil {
    // handle err
}

err = cli.CreateDatabase(ctx, milvusclient.NewCreateDatabaseOption("my_database_1"))
if err != nil {
    // handle err
}

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

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/databases/create" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "dbName": "my_database_1"
}'

You can also set properties for the database when you create it. The following example sets the number of replicas of the database.

client.create_database(
    db_name="my_database_2",
    properties={
        "database.replica.number": 3
    }
)

Map<String, String> properties = new HashMap<>();
properties.put("database.replica.number", "3");
CreateDatabaseReq createDatabaseReq = CreateDatabaseReq.builder()
        .databaseName("my_database_2")
        .properties(properties)
        .build();
client.createDatabase(createDatabaseReq);

await client.createDatabase({
    db_name: "my_database_2",
    properties: {
        "database.replica.number": 3
    }
});

err := cli.CreateDatabase(ctx, milvusclient.NewCreateDatabaseOption("my_database_2").WithProperty("database.replica.number", 3))
if err != nil {
    // handle err
}

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

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/databases/create" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "dbName": "my_database_2",
    "properties": {
        "database.replica.number": 3
    }
}'

View databases

You can use the Milvus RESTful API or SDKs to list all existing databases and view their details.

# List all existing databases
client.list_databases()

# Output
# ['default', 'my_database_1', 'my_database_2']

# Check database details
client.describe_database(
    db_name="default"
)

# Output
# {"name": "default"}

import io.milvus.v2.service.database.response.*;

ListDatabasesResp listDatabasesResp = client.listDatabases();

DescribeDatabaseResp descDBResp = client.describeDatabase(DescribeDatabaseReq.builder()
        .databaseName("default")
        .build());

await client.describeDatabase({ 
    db_name: 'default'
});

// List all existing databases
databases, err := cli.ListDatabase(ctx, milvusclient.NewListDatabaseOption())
if err != nil {
    // handle err
}
log.Println(databases)

db, err := cli.DescribeDatabase(ctx, milvusclient.NewDescribeDatabaseOption("default"))
if err != nil {
    // handle err
}
log.Println(db)

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

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/databases/describe" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "dbName": "default"
}'

Manage database properties

Each database has its own properties, you can set the properties of a database when you create the database as described in Create database or you can alter and drop the properties of any existing database.

The following table lists possible database properties.

Property Name	Type	Property Description
database.replica.number	integer	The number of replicas for the specified database.
database.resource_groups	string	The names of the resource groups associated with the specified database in a common-separated list.
database.diskQuota.mb	integer	The maximum size of the disk space for the specified database, in megabytes (MB).
database.max.collections	integer	The maximum number of collections allowed in the specified database.
database.force.deny.writing	boolean	Whether to force the specified database to deny writing operations.
database.force.deny.reading	boolean	Whether to force the specified database to deny reading operations.

Alter database properties

You can alter the properties of an existing database as follows. The following example limits the number of collections you can create in the database.

client.alter_database_properties(
    db_name: "my_database_1",
    properties: {
        "database.max.collections": 10
    }
)

client.alterDatabaseProperties(AlterDatabasePropertiesReq.builder()
        .databaseName("my_database_1")
        .property("database.max.collections", "10")
        .build());

await milvusClient.alterDatabaseProperties({
  db_name: "my_database_1",
  properties: {"database.max.collections", "10" },
})

err := cli.AlterDatabaseProperties(ctx, milvusclient.NewAlterDatabasePropertiesOption("my_database_1").
    WithProperty("database.max.collections", 1))
if err != nil {
    // handle err
}

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

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/databases/alter" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "dbName": "my_database",
    "properties": {
        "database.max.collections": 10
    }
}'

Drop database properties

You can also reset a database property by dropping it as follows. The following example removes the limit on the number of collections you can create in the database.

client.drop_database_properties(
    db_name: "my_database_1",
    property_keys: [
        "database.max.collections"
    ]
)

client.dropDatabaseProperties(DropDatabasePropertiesReq.builder()
        .databaseName("my_database_1")
        .propertyKeys(Collections.singletonList("database.max.collections"))
        .build());

await milvusClient.dropDatabaseProperties({
  db_name: my_database_1,
  properties: ["database.max.collections"],
});

err := cli.DropDatabaseProperties(ctx, milvusclient.NewDropDatabasePropertiesOption("my_database_1", "database.max.collections"))
if err != nil {
    // handle err
}

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

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/databases/alter" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "dbName": "my_database",
    "propertyKeys": [
        "database.max.collections"
    ]
}'

Drop database

Once a database is no longer needed, you can drop the database. Note that:

• Default databases cannot be dropped.

• Before dropping a database, you need to drop all collections in the database first.

You can use the Milvus RESTful API or SDKs to create data programmatically.

client.drop_database(
    db_name="my_database_2"
)

client.dropDatabase(DropDatabaseReq.builder()
        .databaseName("my_database_2")
        .build());

await milvusClient.dropDatabase({
  db_name: "my_database_2",
});

err = cli.DropDatabase(ctx, milvusclient.NewDropDatabaseOption("my_database_2"))
if err != nil {
    // handle err
}

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

curl --request POST \
--url "${CLUSTER_ENDPOINT}/v2/vectordb/databases/drop" \
--header "Authorization: Bearer ${TOKEN}" \
--header "Content-Type: application/json" \
-d '{
    "dbName": "my_database"
}'