[Bug]: For pk field, it was not allowed to firstly load the index and then load the field data.

[v1incent]

Is there an existing issue for this?

• I have searched the existing issues

Environment

- Milvus version: master branch
- Deployment mode(standalone or cluster):
- MQ type(rocksmq, pulsar or kafka):    
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

For sealed segment and pk field, it was not allowed to firstly load the index and then load the field data.
The related code is in LoadFieldData in SegmentSealedImpl.cpp,

AssertInfo(insert_record_.empty_pks(), "already exists");

Expected Behavior

No response

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

[yanliang567]

/assign @liliu-z
please help to take a look at this issue and related pr

/unassign