Collection schema contains all the base information of a collection including **collection name**, **description**, **autoID** and **fields**. Collection description is defined by database manager to describe the collection. **autoID** determines whether the ID of each row of data is user-defined. If **autoID** is true, our system will generate a unique ID for each data. If **autoID** is false, user need to give each entity a ID when insert.
**Fields** is a list of **FieldSchema**. Each schema should include Field **name**, **description**, **dataType**, **type_params** and **index_params**.
FieldSchema struct is shown as follows:
```protobuf
message FieldSchema {
string name = 1;
string description = 2;
DataType data_type = 3;
repeated common.KeyValuePair type_params = 4;
repeated common.KeyValuePair index_params = 5;
}
```
**Field schema** contains all the base information of a field including field **name**, **description**, **data_type**, **type_params** and **index_params**. **data_type** is a enum type to distingush different data type.Total enum is shown in the last of this doc
**type_params** contains the detailed information of data_type. For example, vector data type should include dimension information. You can give a pair of <dim,8> to let the field store 8-dimension vector.
**index_params**：For fast search, you build index for field. You specify detailed index information for a field. Detailed information about index can be seen in chapter 2.2.3
**Returns:**
- **common.Status**
```protobuf
message Status {
ErrorCode error_code = 1;
string reason = 2;
}
```
**Status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**CollectionName** contains only a string named **collection_name**. Collection with the same collection_name is going to be deleted.
**Returns:**
- **common.Status**
```protobuf
message Status {
ErrorCode error_code = 1;
string reason = 2;
}
```
**Status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**CollectionName** contains only a string named **collection_name**. The server finds the collection through collection_name and judge whether the collection exists.
**Returns:**
- **BoolResponse**
```protobuf
message BoolResponse {
common.Status status = 1;
bool value = 2;
}
```
**status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**value** represents whether the collection exists. If collection exists, value will be true. If collection doesn't exist, value will be false.
**CollectionName** contains only a string named **collection_name**. The server finds the collection through collection_name and get detailed collection information
**Returns:**
- **CollectionDescription**
```protobuf
message CollectionDescription {
common.Status status = 1;
schema.CollectionSchema schema = 2;
repeated common.KeyValuePair statistics = 3;
}
```
**status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**schema** is collection schema same as the collection schema in [CreateCollection](#311-createcollection).
**statitistics** is a statistic used to count various information, such as the number of segments, how many rows there are, the number of visits in the last hour, etc.
**status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**values** is a list contains all collections' name.
**PartitionName** contains only a string named **partition_name**. The server creates partition with the partition_name
- **Returns:**
- **common.Status**
```protobuf
message Status {
ErrorCode error_code = 1;
string reason = 2;
}
```
**Status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**PartitionName** contains only a string named **partition_name**. Partition with the same partition_name is going to be deleted.
**Returns:**
- **common.Status**
```protobuf
message Status {
ErrorCode error_code = 1;
string reason = 2;
}
```
**Status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**PartitionName** contains only a string named **partition_name**. Partition with the same partition_name is going to be tested.
**Returns:**
- **BoolResponse**
```protobuf
message BoolResponse {
common.Status status = 1;
bool value = 2;
}
```
**status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**value** represents whether the partition exists. If partition exists, value will be true. If partition doesn't exist, value will be false.
**PartitionName** contains only a string named **partition_name**. The server finds the partition through partition_name and get detailed partition information
**Returns:**
- **PartitionDescription**
```protobuf
message PartitionDescription {
common.Status status = 1;
PartitionName name = 2;
repeated common.KeyValuePair statistics = 3;
}
```
**status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**name** is partition_name same as the PartitionName in [CreatePartition](#316-createpartition).
**statitistics** is a statistic used to count various information, such as the number of segments, how many rows there are, the number of visits in the last hour, etc.
**CollectionName** contains only a string named **collection_name**. Partition with the same collection_name is going to be listed.
**Returns:**
- **StringListResponse**
```protobuf
message StringListResponse {
common.Status status = 1;
repeated string values = 2;
}
```
**status** represents the server error code. It doesn't contains grpc error but contains the server error code. We can get the executing result in common status. **error_code** is a enum type to distingush the executing error type. The total Errorcode is shown in the last of this code. And the **reason** field is a string to describes the detailed error.
**values** is a list contains all partitions' name.
