variable-length strings with a specified maximum length.

Enum value maps for DataType.

Enum value maps for DataType.

Enum value maps for FieldState.

Enum value maps for FieldState.

For special fields such as bigdecimal, array...

clustering distribution info of a certain data unit, it can be segment, partition, etc.

* @brief Collection schema.

* @brief Field schema.

Scalar field clustering info todo more definitions: min/max, etc.

beta, api may change.

vector field clustering info.

* @brief Field data type.