Solr Atomic update change value and field name

[Hup Chen]

I am new to Solr. I tried to do Atomic update by using .json file update. 
$SOLR/bin/post not only changing field values, but field name also has become 
"fieldname.set", for instance, "price" become "price.set".  Update by curl 
/update handler was working well but since I have several millions of records, 
I can't update by calling curl several million times, that will be extremely 
slow.

Any help will be appreciated.


    # /usr/local/solr/bin/solr version
    8.5.1

    # curl http://localhost:8983/solr/books/select?q=id%3A0371558727
    "response":{"numFound":1,"start":0,"docs":[
      {
        "id":"0371558727",
        "price":19.0,
        "_version_":1667214802265571328}]
    }

    # cat test.json
    [
    {"id":"0371558727",
     "price":{"set":19.95}
    }
    ]

    # /usr/local/solr/bin/post -p 8983 -c books test.json

    # curl http://localhost:8983/solr/books/select?q=id%3A0371558727
    "response":{"numFound":1,"start":0,"docs":[
      {
        "id":"0371558727",
        "price.set":[19.95],
        "_version_":1667214933776924672}]
    }