Check Collection Information

This topic describes how to check the information of the collection in Milvus.

Check if a collection exists

Verify if a collection exists in Milvus.

from pymilvus import utility
utility.has_collection("book")

await milvusClient.hasCollection({
  collection_name: "book",
});

hasColl, err := milvusClient.HasCollection(
  context.Background(), // ctx
  collectionName,       // CollectionName
)
if err != nil {
  log.Fatal("failed to check whether collection exists:", err.Error())
}
log.Println(hasColl)

R<Boolean> respHasCollection = milvusClient.hasCollection(
  HasCollectionParam.newBuilder()
    .withCollectionName("book")
    .build()
);
if (respHasCollection.getData() == Boolean.TRUE) {
  System.out.println("Collection exists.");
}

describe collection -c book

curl -X 'GET' \
  'http://localhost:9091/api/v1/collection/existence' \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
    "collection_name": "book"
  }'

{
  "status":{},
  "value":true
}

Check collection details

Check the details of a collection.

from pymilvus import Collection
collection = Collection("book")  # Get an existing collection.

collection.schema                # Return the schema.CollectionSchema of the collection.
collection.description           # Return the description of the collection.
collection.name                  # Return the name of the collection.
collection.is_empty              # Return the boolean value that indicates if the collection is empty.
collection.num_entities          # Return the number of entities in the collection.
collection.primary_field         # Return the schema.FieldSchema of the primary key field.
collection.partitions            # Return the list[Partition] object.
collection.indexes               # Return the list[Index] object.
collection.properties       # Return the expiration time of data in the collection.

await milvusClient.describeCollection({          // Return the name and schema of the collection.
  collection_name: "book",
});

await milvusClient.getCollectionStatistics({     // Return the statistics information of the collection.
  collection_name: "book",
});

collDesc, err := milvusClient.DescribeCollection(               // Return the name and schema of the collection.
  context.Background(),   // ctx
  "book",                 // CollectionName
)
if err != nil {
  log.Fatal("failed to check collection schema:", err.Error())
}
log.Printf("%v\n", collDesc)

collStat, err := milvusClient.GetCollectionStatistics(          // Return the statistics information of the collection.
  context.Background(),   // ctx
  "book",                 // CollectionName
)
if err != nil {
  log.Fatal("failed to check collection statistics:", err.Error())
}

R<DescribeCollectionResponse> respDescribeCollection = milvusClient.describeCollection(
  // Return the name and schema of the collection.
  DescribeCollectionParam.newBuilder()
    .withCollectionName("book")
    .build()
);
DescCollResponseWrapper wrapperDescribeCollection = new DescCollResponseWrapper(respDescribeCollection.getData());
System.out.println(wrapperDescribeCollection);

R<GetCollectionStatisticsResponse> respCollectionStatistics = milvusClient.getCollectionStatistics(
  // Return the statistics information of the collection.
  GetCollectionStatisticsParam.newBuilder()
    .withCollectionName("book")
    .build()
  );
GetCollStatResponseWrapper wrapperCollectionStatistics = new GetCollStatResponseWrapper(respCollectionStatistics.getData());
System.out.println("Collection row count: " + wrapperCollectionStatistics.getRowCount());

describe collection -c book

curl -X 'GET' \
  '${MILVUS_HOST}:${MILVUS_PORT}/v1/vector/collections/describe' \
  -H 'Authorization: Bearer ${TOKEN}' \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
    "collectionName": "book"
  }'

// Output of describeCollection
{
    "code": 200,
    "data": {
        "collectionName": "string",
        "description": "string",
        "fields": [
            {
                "autoId": true,
                "description": "string",
                "name": "string",
                "primaryKey": true,
                "type": "string"
            }
        ],
        "indexes": [
            {
                "fieldName": "string",
                "indexName": "string",
                "metricType": "string"
            }
        ],
        "load": "string",
        "shardsNum": 0,
        "enableDynamic": true
    }
}

List all collections

List all collections in this Milvus Instance.

from pymilvus import utility
utility.list_collections()

await milvusClient.showCollections();

listColl, err := milvusClient.ListCollections(
  context.Background(),   // ctx
)
if err != nil {
  log.Fatal("failed to list all collections:", err.Error())
}
log.Println(listColl)

R<ShowCollectionsResponse> respShowCollections = milvusClient.showCollections(
    ShowCollectionsParam.newBuilder().build()
  );
System.out.println(respShowCollections);

list collections

curl -X 'GET' \
  '${MILVUS_HOST}:${MILVUS_PORT}/v1/vector/collections' \
  -H 'Authorization: Bearer ${TOKEN}' \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json'

// Output of list collections
{
   code: 200,
   data: [
         "collection1",
         "collection2",
         ...
         "collectionN",
         ]
}

What’s next

• Learn more basic operations of Milvus:
  • Insert data into Milvus
  • Create a partition
  • Build an index for vectors
  • Conduct a vector search
  • Conduct a hybrid search