Database / Supabase Intermediate to Advanced Interview Questions

How is Storage object access controlled compared to table-level Row Level Security?

Supabase Storage objects are actually tracked as rows in an internal storage.objects table, so access control uses the exact same Row Level Security mechanism as any other table — policies with USING and WITH CHECK expressions — rather than a separate, bucket-specific permission system.

A typical policy restricts access based on the object's path, for example allowing a user to read or write only within a folder matching their own user ID: bucket_id = 'avatars' and (storage.foldername(name))[1] = auth.uid()::text. This means the same mental model, and the same debugging techniques, used for table RLS apply directly to file access — there's no separate storage-permissions language to learn.

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What underlying mechanism controls access to Storage objects? The same Row Level Security policies used for regular tables

✓ Correct! Well done.

A completely separate, storage-specific permission language

✗ Try again, that's not it.

File system permissions on the server's disk

✗ Try again, that's not it.

IP address whitelisting only

✗ Try again, that's not it.

What table internally tracks Storage objects for policy purposes? public.files

✗ Try again, that's not it.

storage.objects

✓ Correct! Well done.

realtime.messages

✗ Try again, that's not it.

auth.users

✗ Try again, that's not it.

More Related questions...

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