Firebase realtime DB - limitations of paths and keys?

Question

In Firebase Realtime DB, what are the limits on:

• keys
• paths
• nesting level

?

Meaning restrictions on lengths as well as disallowed/special chars/values. And any other restrictions (or discouragements) there might be.

Is this deprecated pre-Google-integration document (link here) still up to date?

Length of a key: 768 bytes

Depth of child nodes: 32

I don't see max path length mentioned there.

What is the non-deprecated location for this documentation?

I cannot find an equivalent in https://firebase.google.com/docs/ . As if some of the docs "got lost in the shuffle"...

Thanks for any hints.

EDIT: I've broadened it slightly - not just lengths but any restrictions that might apply.

Answer 1

The Firebase documentation says 768 bytes is still the limit for a Key, and that they use UTF-8 encoding. With UTF-8, a character is 1-4 bytes.

However, most characters are 1 byte, unless you use a character such as ♥, which is 3 bytes. Therefore, for normal use of a key, the character limit is 768. If you want to anticipate some outlandish characters, it may be best to be conservative and limit total characters to 500 ,600, or 700. Depends on how you want to use the keys.

Test your characters and strings here: https://mothereff.in/byte-counter

Documentation here: https://firebase.google.com/docs/database/usage/limits

Answer 2

This documentation mentions that firebase realtime database can be nested up to 32 levels. But as its mentioned there itself that it is not a good practice to nest your data. Denormalisation of data though seems redundant, it gives more flexibility when writing rules and when writing queries to the database.