Patent attributes
A constraint system enforces projection constraints on data values stored in specified columns of a shared dataset when queries are received by a database system. A projection constraint identifies that the data in a column may be restricted from being projected (e.g., presented, read, outputted) in an output to a received query, while allowing specified operations to be performed on the data and a corresponding output to be provided. For example, the projection constraint may indicate a context for a query that triggers the constraint, such as based on the user that submitted the query. Enforcing projection constraints on queries received at the database system allows for data to be shared and used anonymously by entities to perform various operations without the need to tokenize the data.
