Firebase: How to add an index for a nested field? - firebase

Question

I have a locations-orders table that looks like this:
{
"0BW3H9T3R7HJB" : {
"orders" : {
"01750ea0-4980-4bc4-58b2-988c02324e671478636582396" : {
"created_at" : 1478636560000,
},
"01750ea0-4980-4bc4-58b2-988c02324e671478636582483" : {
"created_at" : 1478636560000,
}
}
}
Each location-orders node has an orders node with multiple keys/objects. Those objects have a created_at field on it.
I added this to my database Rules:
{
"rules": {
".read": true,
".write": true,
"users": {
".indexOn": "merchantId"
},
"merchants": {
".indexOn": "locations"
},
"locations-orders": {
".indexOn": ["orders/created_at"]
}
}
}
However, Firebase is still complaining that I'm missing an index:
Using an unspecified index. Consider adding ".indexOn": "created_at" at /locations-orders/1JS53G0TT5ZQD/orders to your security rules for better performance
Am I supposed to run something to create the index? Or is it written incorrectly?
=== UPDATE ===
I changed my file to look into:
{
"rules": {
".read": true,
".write": true,
"users": {
".indexOn": "merchantId"
},
"merchants": {
".indexOn": "locations"
},
"locations-orders": {
"$location_id": {
".indexOn": ["orders/created_at", "orders/status_updated_at"]
}
}
}
}
but I still get the same warning:
Using an unspecified index. Consider adding ".indexOn": "created_at" at /locations-orders/1JS53G0TT5ZQD/orders to your security rules for better performance

Answer 1

If you look at your data structure, there is no orders/created_at under /location-order/$orderId.
{
"rules": {
".read": true,
".write": true,
"users": {
".indexOn": "merchantId"
},
"merchants": {
".indexOn": "locations"
},
"locations-orders": {
"$someid": {
".indexOn": ["orders/created_at"]
}
}
}
}

Answer 2

Try this:
{
"rules": {
".read": true,
".write": true,
"users": {
".indexOn": "merchantId"
},
"merchants": {
".indexOn": "locations"
},
"locations-orders": {
"orders": {
"$orderid": {
".indexOn": "created_at"
}
}
}
}
}