在 Firebase 实时数据库中，.indexOn 规则会增加数据库的容量吗？

Question

Based on this answer which states:

It creates some indexes ahead of time, but you need to tell it when you want to query with nested children with orderByChild orderByValue.

Does this mean that the DB multiplies the branch for each.indexOn rule added + 1?

Lets say I have 3 Megs of data on branch A which is indexed by $key.

If I use a rule:

"A": {".indexOn":["fieldA", "fieldB"]}

Now under the hood Firebase will Create a subbranch of A that will re-insert the indices already found on 'A' but this time under a the key defined in the.indexOn rule:

A--|
   |__rule_field_a
          |
          |_val_of_field_a_1 -> :value_a
          |
          |_val_of_field_a_2 -> :value_b
          |
          etc... etc...

This means that the 2 indexOn rules will multiple the volume of the branch from 3 to 9 Megs.

Is this correct?

Will this get reflected on the pricing?

Answer 1

firebaser here

Indexes that you define on the Firebase Realtime Database inside your security rules are not stored in your database itself, and you are not charged for them.