Can my FireBase database layout cause issues if I use this approach? - firebase-realtime-database

Question

I have a FireBase structure that looks like this. I want to represent all countries in the world.
In this sample code there is only 9 countries and only United States and Venezuela have data to demonstrate my problem.
I have denormalization and flattens the data as much as I can.
What happens her is that user can search for street addresses like
US/California/Orange County/Orange/3138 E Maple Ave
In the db below it looks like this:
US/ADMINISTRATIVE_AREA_LEVEL_1/
US/ADMINISTRATIVE_AREA_LEVEL_2
US/LOCALITY
US/STREET_ADDRESS
....
....
"AE": {
"name": "United Arab Emirates"
},
"GB": {
"name": "United Kingdom"
},
"US": {
"name": "United States"
"ADMINISTRATIVE_AREA_LEVEL_1": {
"hjg86tghg8hubyhiuhb88ihi": {
"level1": "California"
},
},
"ADMINISTRATIVE_AREA_LEVEL_2": {
"hjg86tghg8hubyhiuhb88ihi": {
"level2": "Orange County"
},
},
"LOCALITY": {
"hjg86tghg8hubyhiuhb88ihi": {
"level2": "Orange"
},
},
"STREET_ADDRESS": {
"hjg86tghg8hubyhiuhb88ihi": {
"3138 E Maple Ave": {
}
}
},
"USER_LIST": {
"hjg86tghg8hubyhiuhb88ihi": {
"name": "Jhon Doe",
}
},
"CHAT_LIST": {
"hjg86tghg8hubyhiuhb88ihi": {
"title": "Wam-Bam-CHAT",
}
},
"chat_members": {
"hjg86tghg8hubyhiuhb88ihi": {
}
},
"chat_messages": {
"hjg86tghg8hubyhiuhb88ihi": {
},
},
"UM": {
"name": "United States Minor Outlying Islands"
},
"UY": {
"name": "Uruguay"
},
"UZ": {
"name": "Uzbekistan"
},
"VU": {
"name": "Vanuate"
},
"VE": {
"name": "Venezuela"
"ADMINISTRATIVE_AREA_LEVEL_1": {
"swdkewsjdr34378943489324": {
"level1": "California"
},
},
"ADMINISTRATIVE_AREA_LEVEL_2": {
"swdkewsjdr34378943489324": {
"level2": "Orange County"
},
},
"LOCALITY": {
"swdkewsjdr34378943489324": {
"level2": "Orange"
},
},
"STREET_ADDRESS": {
"swdkewsjdr34378943489324": {
"3138 E Maple Ave": {
}
}
},
"USER_LIST": {
"swdkewsjdr34378943489324": {
"name": "Jhon Doe",
}
},
"CHAT_LIST": {
"swdkewsjdr34378943489324": {
"title": "Wam-Bam-CHAT",
}
},
"chat_members": {
"swdkewsjdr34378943489324": {
}
},
"chat_messages": {
"swdkewsjdr34378943489324": {
},
},
"VN": {
"name": "Viet Nam"
....
....
When I create the Realtime Database Rules likes this: I have to create 240 root nods because of 240 countries right.
There´s a loot of ".read": "$uid === auth.uid" and a loot of duplicate json since all ADMINISTRATIVE_AREA_LEVEL_1 and others looks the same.
If i put the ADMINISTRATIVE_AREA_LEVEL_1 as a root i will maybe have miljons of entries and for the STREET_ADDRESS there is 154 million alone for United States not to speak of the "world". So I group them like this, having the Country as key root node.
Small sample:
{
"rules": {
"SE": {
"ADMINISTRATIVE_AREA_LEVEL_1": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
}
},
"VE": {
"ADMINISTRATIVE_AREA_LEVEL_1": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
}
}
}
}
My question is how can I furthermore make this more efficient and what bottleneck(s) can I look forward to. Is there a way to have this structure and centrally set a rule without explicitly writing it at all location
UPDATE
Probably i get this wrong but anyway here goes, after #FrankvanPuffelen answer I try this: Must test run this but does this work on all 240 countries in my above code..
{
"rules": {
"$country": {
"ADMINISTRATIVE_AREA_LEVEL_1": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
},
"ADMINISTRATIVE_AREA_LEVEL_2": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
},
"LOCALITY": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
},
....and more
}
}
}
UPDATE
Yes it works with a little tweek
{
"rules": {
"$hubaBuba": {
"ADMINISTRATIVE_AREA_LEVEL_1": {
".read": "auth != null",
".write": "auth != null",
},
"ADMINISTRATIVE_AREA_LEVEL_2": {
".read": "auth != null",
".write": "auth != null",
},
"LOCALITY": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
},
....and more
}
}

Answer 1

If the rules for each country are the same, you can use a wildcard for the country:
{
"rules": {
"$country": {
"ADMINISTRATIVE_AREA_LEVEL_1": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
}
}
}
}