Database

Firebase

Firebase is an app development platform built around non-relational technologies. The Firebase Wrapper supports connecting to below objects.

  1. Authentication Users (read only)
  2. Firestore Database Documents (read only)

Preparation

Before you get started, make sure the wrappers extension is installed on your database:


_10
create extension if not exists wrappers with schema extensions;

and then create the foreign data wrapper:


_10
create foreign data wrapper firebase_wrapper
_10
handler firebase_fdw_handler
_10
validator firebase_fdw_validator;

Secure your credentials (optional)

By default, Postgres stores FDW credentials inide pg_catalog.pg_foreign_server in plain text. Anyone with access to this table will be able to view these credentials. Wrappers is designed to work with Vault, which provides an additional level of security for storing credentials. We recommend using Vault to store your credentials.


_11
-- Save your Firebase credentials in Vault and retrieve the `key_id`
_11
insert into vault.secrets (name, secret)
_11
values (
_11
'firebase',
_11
'{
_11
"type": "service_account",
_11
"project_id": "your_gcp_project_id",
_11
...
_11
}'
_11
)
_11
returning key_id;

Connecting to Firebase

We need to provide Postgres with the credentials to connect to Firebase, and any additional options. We can do this using the create server command:

Creating Foreign Tables

The Firebase Wrapper supports reading data from below Firebase's objects:

FirebaseSelectInsertUpdateDeleteTruncate
Authentication Users✅❌❌❌❌
Firestore Database Documents✅❌❌❌❌

For example:


_10
create foreign table firebase_users (
_10
uid text,
_10
email text,
_10
created_at timestamp,
_10
attrs jsonb
_10
)
_10
server firebase_server
_10
options (
_10
object 'auth/users'
_10
);

Note there is a meta column attrs in the foreign table, which contains all the returned data from Firebase as json format.

Foreign table options

The full list of foreign table options are below:

  • object - Object name in Firebase, required.

    For Authenciation users, the object name is fixed to auth/users. For Firestore documents, its format is firestore/<collection_id>, note that collection id must be a full path id. For example,

    • firestore/my-collection
    • firestore/my-collection/my-document/another-collection

Query Pushdown Support

This FDW doesn't support query pushdown.

Examples

Some examples on how to use Firebase foreign tables.

firestore

To map a Firestore collection provide its location using the format firestore/<collection_id> as the object option as shown below.


_10
create foreign table firebase_docs (
_10
name text,
_10
created_at timestamp,
_10
updated_at timestamp,
_10
attrs jsonb
_10
)
_10
server firebase_server
_10
options (
_10
object 'firestore/user-profiles'
_10
);

Note that name, created_at, and updated_at, are automatic metadata fields on all Firestore collections.

auth/users

The auth/users collection is a special case with unique metadata. The following shows how to map Firebase users to PostgreSQL table.


_10
create foreign table firebase_users (
_10
uid text,
_10
email text,
_10
created_at timestamp,
_10
attrs jsonb
_10
)
_10
server firebase_server
_10
options (
_10
object 'auth/users'
_10
);