Optimizing aggregate processing

A method for making a computer implemented process to enable processing of an aggregate function, said method comprising:

• instantiating first computer instructions onto a computer readable medium, said first computer instructions configured to, if a first argument of the aggregate function is a nested function, generate a composite structure that includes a tagging template for the nested function and generate an intermediate result structure for each row to be processed by the aggregate function, wherein each intermediate result structure references the tagging template;
• instantiating second computer instructions onto a computer readable medium, said second computer instructions configured to group rows that contain a reference to intermediate result structures to form groups, wherein each of the intermediate result structures holds intermediate results including argument input values to represent different levels of nested functions;
• and
• instantiating third computer instructions onto a computer readable medium, said third computer instructions configured to, for each group, form aggregate element structures in memory from the intermediate result structures and, if the aggregate function specifies ordering, sort the aggregate element structures based on a sort key in memory.