Set function calculation in a database

A non-transitory computer readable medium comprising instructions thereon to cause one or more processors of a computer to perform a computer implemented method of calculating a set function, including criteria, defined against fields in a table in a database, the method comprising:

• creating an index list, using a processor of the computer, from at least one of the fields, the index list comprising nodes and having position counters in at least each node of the index list and further the index list having positional awareness whereby each of the nodes is enabled to identify its relative position within the index list;
• traversing the index list, using the processor of the computer, and finding values of the index list consistent with the criteria;
• utilizing the positional awareness by identifying a first positional counter corresponding to a first value of the index list, and a second positional counter value corresponding to a second value of the index list, and determining a number of records, associated with the first value based on the first and second positional counters, without reading the records;
• calculating a set function from the positional awareness of the index list;
• and
• using the calculation to provide a response to a query to the database.

A computer system comprising:

• a memory;
• and
• one or more processors communicatively coupled to the memory wherein, the memory comprises instructions stored therein to cause the one or more processors to perform a computer implemented method of calculating a set function, including criteria, defined against fields in a table in a database, the method comprising:
• creating an index list, using a processor of the computer, from at least one of the fields, the index list comprising nodes and having position counters in at least each node of the index list and further the index list having positional awareness whereby each of the nodes is enabled to identify its relative position within the index list;
• traversing the index list, using the processor of the computer, and finding values of the index list consistent with the criteria;
• utilizing the positional awareness by identifying a first positional counter corresponding to a first value of the index list, and a second positional counter value corresponding to a second value of the index list, and determining a number of records, associated with the first value based on the first and second positional counters, without reading the records;
• calculating a set function from the positional awareness of the index list;
• and
• using the calculation to provide a response to a query to the database.