Is DynamoDB a good choice for a multi-tenant file management service?

I am planning to build a file management microservice for a multi-tenant SaaS platform that uses Amazon S3 as the file storage backend. I intend to use DynamoDB as the database because it is fast and scalable. The platform may host many tenants, with each tenant having many users, and each user having many files in their storage space. I need to keep a record of each file's metadata and the user directory structure (hierarchy) in the database. However, I'm uncertain if DynamoDB is the best choice. A user might want to list all their directories and files, search by name, or sort them alphabetically or by creation date. This could lead to the "hot partition" problem (at least for Global Secondary Indexes). The situation could become even more challenging when tracking all the files uploaded by all users within a tenant. Therefore, I am considering a hybrid approach: using PostgreSQL for relational data and DynamoDB for storing file information and directory hierarchies. What are your thoughts on this idea? Can anyone point me in the right direction? Thanks in advance.