The provider currently implements GetAsync by placing the document ID (and partition key) in the SQL WHERE clause; this is quite bad for performance and isn't the way Cosmos is meant to be used. Point reads - where a document is fetched via its ID and partition key - are performed via a specialized ReadItem call, which makes the Cosmos SDK directly and efficiently read the document from the right partition.

Also, for non-ReadItem queries that do use SQL, partition keys should not be in the WHERE clause, but rather passed separately to the SDK in the request, against for far more efficient retrieval.