Firebase Realtime Database：选择短路径/键名称是否可降低使用成本？

Great question—this is a critical detail for anyone looking to optimize Firebase RTDB costs, since unlike Firestore, RTDB charges based on the total volume of data downloaded rather than the number of operations.

Let’s break this down clearly:

• Yes, all keys (including path segments like path1/path2 and individual key-value pair keys) are included in the downloaded data volume. When you call something like database.child(path1).child(path2).getData(), RTDB sends the full JSON structure at that location to your client. This structure includes every key in the hierarchy (from the top-level path segments down to each individual key in your 1 million key-value pairs) along with their corresponding values. Every character in those keys contributes to the total bytes downloaded, which directly impacts your billing.

• Shortening key lengths will absolutely reduce your usage costs. In your specific scenario:

  • A boolean value (true/false) only takes 4-5 bytes in JSON.
  • If you cut each key from 200 characters to 10, you’re saving ~190 bytes per key (assuming UTF-8 encoding, where most characters are 1 byte). For 1 million keys, that’s a total savings of ~190MB of downloaded data. Since RTDB bills per GB downloaded, this will translate directly to lower costs over time.

As a quick best practice: If cost efficiency is a priority, keep your path segments and key names as concise as possible without sacrificing readability for your team. Every byte adds up, especially when dealing with large datasets like your 1 million entry example.

内容的提问来源于stack exchange，提问作者lukasniessen