Processing query predicates involving fine-grained privacy-preserving columns

A system of processing query predicates involving fine-grained privacy-preserving columns, comprising:

• at least one processor;
• and
• at least one memory communicatively coupled to the at least one processor and comprising computer-readable instructions that upon execution by the at least one processor cause the at least one processor to perform operations comprising:
• receiving a query predicate involving a fine-grained privacy-preserving column, wherein the fine-grained privacy-preserving column contains secret information;
• searching a predicate catalog table and determining whether there is a first match between identification information and operator information in a first row of the predicate catalog table and information associated with the query predicate, wherein each row of the predicate catalog table comprises identification information identifying a particular fine-grained privacy-preserving column and a particular predicate survivor user, operator information indicating one or more predicate operators, a quantity limit that the particular predicate survivor user is allowed to query the particular fine-grained privacy-preserving column using the one or more predicate operators, and an interval at which the quantity limit is to be reset;
• determining whether a value of a quantity limit in the first row is greater than zero in response to determining that there is the first match between the identification information and the operator information in the first row and the information associated with the query predicate;
• executing the query predicate in response to determining that the value of the quantity limit in the first row is greater than zero;
• and
• automatically reducing the value of the quantity limit in the first row by one and automatically updating the predicate catalog table.

A non-transitory computer-readable storage medium, storing computer-readable instructions that upon execution by a processor cause the processor to implement operations comprising:

• receiving a query predicate involving a fine-grained privacy-preserving column, wherein the fine-grained privacy-preserving column contains secret information;
• searching a predicate catalog table and determining whether there is a first match between identification information and operator information in a first row of the predicate catalog table and information associated with the query predicate, wherein each row of the predicate catalog table comprises identification information identifying a particular fine-grained privacy-preserving column and a particular predicate survivor user, operator information indicating one or more predicate operators, a quantity limit that the particular predicate survivor user is allowed to query the particular fine-grained privacy-preserving column using the one or more predicate operators, and an interval at which the quantity limit is to be reset;
• determining whether a value of a quantity limit in the first row is greater than zero in response to determining that there is the first match between the identification information and the operator information in the first row and the information associated with the query predicate;
• executing the query predicate in response to determining that the value of the quantity limit in the first row is greater than zero;
• and
• automatically reducing the value of the quantity limit in the first row by one and automatically updating the predicate catalog table.