Firebase Realtime Database indexing for query optimization

fiebaseIndexing.js

Data Format: 
_DB
___Collction
______Sub Collection
__________Data


TestChatHistory --------------------------------------->(Main DB)
>268  ------------------------------------------------->(Collection)
>>2691680604235655  ----------------------------------->(Sub-collection)
----------groupChatRoomId : "2691680604235655" -------->(Data)
----------hisId:"0"
----------timestamp:1680604235865
>>2691680607831444
>>2701680602838840
>269


-------------------Firebase Roles------------------------
{
  "rules": {
    ".write": "now < 1683741600000",  // 2023-5-11
    "268": {
    	".indexOn": ["timestamp"]
  },
  }
}